PHOTOPTICS 2018 Abstracts


Area 1 - Lasers

Full Papers
Paper Nr: 7
Title:

Research Progress of Fiber-based Coherent Polarization Beam Combining for Free-Space Optical Communications in IOE, CAS

Authors:

Yan Yang, Chao Geng, Xinyang Li, Feng Li and Guan Huang

Abstract: Multi-aperture receiver with phased array is an effective approach to overcome the atmospheric turbulence effect on the performance of the fiber-based free-space optical (FSO) communications, where how to combine the multiple beams received by the sub-apertures efficiently is one of the key techniques. In this paper, we report on the research progress of the fiber-based coherent polarization beam combining (CPBC) in IOE, CAS, which is a promising beam combining solution for coherent FSO communications employing the multi-aperture receiver. Phase-locking control and polarization-transforming control were proposed to combine linearly polarized beams with orthogonal polarizations into one linearly polarized beam efficiently, and three fiber-based CPBC schemes were proposed and experimentally validated.

Paper Nr: 16
Title:

Research Progress of Multi-aperture Laser Transceiving Control for Beam Combining Applications in IOE, CAS

Authors:

Feng Li, Xinyang Li, Chao Geng, Guan Huang and Yan Yang

Abstract: Nowadays, the development of fiber laser beam combining faces new challenges during propagating through the real long-range atmosphere. Aberrations in such transmission systems include turbulence-induced dynamic aberrations located at the path from the fiber laser array to the target, besides the inherent phase errors like phase noises and tip/tilt errors. Existing techniques, e.g., target-in-the-loop and delayed stochastic parallel gradient descent, are difficult to deal with the fast-changing turbulence-induced tip/tilt aberrations. But correcting these aberrations is critical for obtaining combined laser beams on the target with the best beam quality. In this paper, research progress of multi-aperture laser transceiving control for beam combining applications in IOE, CAS is presented. These novel techniques presented here provide efficient ways to achieve tip/tilt control for the beam coupling from space to fiber and the outgoing laser beams in the beam combining applications.

Paper Nr: 38
Title:

Continuous Tunable Terahertz Wave Generation via a Novel CW Optical Beat Laser Source

Authors:

Muhammad A. Ummy, Simeon Bikorimana, Abdullah Hossain and Roger Dorsinville

Abstract: A novel technique of generating two colors or dual-wavelength in a fiber hybrid compound-ring resonator is discussed. Generation of continuous-wave terahertz radiation is demonstrated by using a dual-wavelength widely tunable C-band SOA-based fiber compound-ring laser as a light source, which excites a continuous-wave terahertz photomixer operating at 1.55 µm telecom optical wavelengths. The proposed dual-wavelength fiber laser has a hybrid compound-ring resonator structure and external reflectors that allow output power upscaling and single or dual-output port operation, respectively. Wavelength selection and continuous tunability are achieved by a widely tunable optical filter sandwiched between two fiber-Bragg grating filters of similar Bragg center wavelength. The difference wavelength tuning range of 20.42 nm (i.e., 2.51 THz) is demonstrated in the C-band. Continuous-wave terahertz radiation with continuous tunability between 0.8 and 2.51 THz at room temperature using only a fiber laser source is achieved via photomixing.

Paper Nr: 73
Title:

Parallel 1d3v Particle in Cell/Monte Carlo Collision (PIC/MCC) Simulation of a Glow Discharge Millimeter Wave Detector

Authors:

Cemre Kusoglu-Sarikaya, Hakan Altan and Demiral Akbar

Abstract: Glow discharge detectors can be a good alternative to existing Schottky diodes, Golay cells and pyroelectric detectors because they are inexpensive and can detect mm-wave and sub-mm radiation successfully. This detection occurs as a result of the interaction of the radiation with the electrons in the plasma. It is required to understand this interaction mechanism to obtain optimum detection parameters. Previous methods have focused on understanding the interaction using analytical models, where the radiation is generally thought to increase the collision frequency of electrons in the plasma, however these theories were not tested against real discharge parameters. For that reason, in this study, the plasma formed inside the detector is simulated by using parallel 1d3v PIC/MCC code, which was previously developed (Kusoglu-Sarikaya et al., 2016) to better understand how the glow discharge forms under different pressure and gas concentrations. The effectiveness of the simulation is compared with mm-wave experiments performed on both commercially obtained and home-built glow discharge detectors. Initial results show that the 1d3v PIC/MCC code can simulate the discharge parameters that are observed in the measurements. Using this platform future studies will focus on understanding the effect of the sub-THz radiation on the collision frequency and observed parameters of the discharge.

Short Papers
Paper Nr: 29
Title:

Laser Drilling of a 7-layer Flexible Printed Circuit Board using a Pulsed Ytterbium Fiber Laser System

Authors:

Chih-Chung Yang, Yi-Cheng Lin, Tzu-Chieh Peng, Kuo-Cheng Huang and Yu-Hsuan Lin

Abstract: Recently, laser-processing industry is becoming increasingly popular because of its advantages of low cost, fast and good energy efficiency. The electric circuit board manufacturers also began to import related laser processing technology to improve the productivity. This paper presents the laser drilling process and quality analysis of the 7-layer flexible printed circuit (FPCB). A laser drilling system pulsed Ytterbium fiber laser, expander device, focal lens, galvanometric scanner and XY-axis manual stage was used to perform the hole cutting of the multilayer-layer FPCB. This study succeeded in establishing a comparing procedure, which enabled the characteristic comparison between the various experimental conditions. We believe that this study provides a useful database for FPCB drilling technology.

Paper Nr: 31
Title:

Surface Formation of Nano- / Micro- Structures on Titanium Alloy Composites using Picosecond Laser Scanning Technology

Authors:

Yi-Cheng Lin, Chih-Chung Yang, Shih-Feng Tseng, Donyau Chiang, Yu-Hsuan Lin, Kuo-Cheng Huang and Wen-Tse Hsiao

Abstract: This study reports on the development of picosecond laser system to titanium alloy surface treatment applications. In the picosecond laser-scanning system, that is based on the fiber-optics laser source and integrated with a designed optics / optical machine design and control technology of scanning system. To analyze the laser material interaction, the laser fluence, pulse repetition frequency of laser source, position of focused points, scan speed and pulse duration were adjusted. After laser surface treatment, the surface roughness and surface morphologies of treated surface were evaluated by using a field emission scanning electron microscope. Moreover, the contact angle measurement was used to analyze the hydrophilic and hydrophobic properties of the treatment surface with micro- / nano- structures.

Paper Nr: 50
Title:

Transmitter Design Proposal for the BB84 Quantum Key Distribution Protocol using Polarization Modulated Vertical Cavity Surface-emitting Lasers

Authors:

Ágoston Schranz and Eszter Udvary

Abstract: Vertical cavity surface-emitting lasers (VCSELs) have multiple beneficial properties for applications in quantum key distribution (QKD). However, polarization switching (PS) characteristic of these lasers can be problematic if it is unwanted. The origin and properties of PS is discussed. We propose a new transmitter design for the BB84 protocol using only two VCSELs – both corresponding to one of the two bases in which polarized photons are sent –, which are modulated in polarization, purposely generating switches between two orthogonally polarized modes. Advantages and design difficulties of this design are outlined. We also consider the possibility of a spectral attack, originating from the frequency splitting between these modes, and offer a solution that can protect the key from eavesdroppers utilizing this kind of attack.

Paper Nr: 76
Title:

Narrow Bandwidth Tunable Watt Level Tm:YAP Laser using Two Etalons

Authors:

Uzziel Sheintop, Eytan Perez and Salman Noach

Abstract: Narrow band, tunable, end pump Tm:YAP laser is demonstrated in this paper. The 35 nm wavelength tunability, ranges continuously from 1917 to 1951 nm, having a spectral linewidth of 0.15 nm FWHM. The tuning and spectral band narrowing was obtained using a pair of YAG Fabry-Perot Etalons with thicknesses of 25 and 500 μm. Watt level output power were measured along the laser tunable range. Maximum output power of 3.84 W was achieved at 1934 nm. Slope efficiency of 43.2% was calculated for an absorbed pump power of 12.1 W. The combination of the narrow bandwidth with tunability at those levels of output power, makes this laser a promising tool for bio-medical, sensing and material processing applications.

Posters
Paper Nr: 41
Title:

Optimization Parameters for Laser-induced Forward Transfer of Al and Cu on Si-wafer Substrate

Authors:

Mohammad Hossein Azhdast, Hans Joachim Eichler, Klaus Dieter Lang and Veronika Glaw

Abstract: The research goal is to perform a laser-writing study to deposition of micro/nano particles on the substrate as interconnection usage. The threshold of laser energy, pulses per laser shot, as well as pulse overlapping is crucial to achieve the best deposition results possible. The present study aims to the novel technique by laser deposition of Aluminium and Copper nano particles on silicon wafer substrate. Thin µm films have been deposited from one-side coated glass to Silicon wafers by sputtering nano particles using laser radiation. Distance between donor film and substrate (ε) was up to several 100 µm and it has been optimized as 300 µm. A step-by-step optimization guide for deposition parameters were first developed and presented. The identification of laser energy threshold, pulses per laser shot, in addition to pulse overlapping is essential if the best deposition results are going to be drawn by laser direct writing method. This technique is regarded as the most important direct-write alternative for lithographic processes in order to generate patterns with high-resolution.

Area 2 - Optics

Full Papers
Paper Nr: 9
Title:

Nanoscale Non-Contact Laser Measurement of Precision Machine Tooling and Optical Surfaces

Authors:

Schubert Soãres

Abstract: Optical and semiconductor products are fabricated utilizing industrial technology that is steadily progressing to nanometre accurate operations. Reliable non-invasive contact-free sensors and techniques are required to monitor in situ manufacturing parameters in parallel with product formation. The real-time evaluation and analysis of precision fabrication processes could lead to intelligent, computerized, sensor-actuated implementation, with automated compensating feedback loops to facilitate nanometre accuracy and consistently provide high quality products in abundant yield. Laser triangulation is demonstrated herewith as a versatile solution to simultaneously measure machine tool components and monitor the product in process. Optically levered reflection resolved on a nanometre resolution displacement sensor, enables the analysis of spindle axial and rotational error, stage linear error, the impact of these error-motion components on a diamond tool edge and its progression to wear, while inspecting the compliance of the product to the desired surface finish and shape. Scanning optical scatterometry is utilized to image and analyse edges, surfaces, defects, and thin film structure. This sensor technology is highly adaptable, and may be utilized in scales ranging from small μm-size to large meter-size products manufactured from a variety of materials.

Paper Nr: 13
Title:

On the Probability Density Function of Inter-core Crosstalk Power in Birefringent Homogeneous Multi-core Fibers

Authors:

Ricardo O. J. Soeiro, Tiago M. F. Alves and Adolfo V. T. Cartaxo

Abstract: In this paper, the inter-core crosstalk (ICXT) of the polarization directions and the probability density functions (PDFs) of the ICXT power of the polarization directions in weakly coupled birefringent homogeneous multi-core fibers (MCFs) are studied through numerical simulation. The numerical simulator is based on the coupled local mode theory (CLMT), which is a rigorous model that has the downside of requiring long computational times to compute the ICXT field and PDFs of the ICXT power. Conversely, a dual-polarization discrete changes model (DP-DCM) that allows for much faster estimates of the ICXT field is presented. It is shown that, for perfectly homogeneous MCFs, the mean ICXT power distribution between the polarization directions is similar, despite the power distribution at the MCF input, for a mean linear birefringence parameter ranging from 10􀀀7 (low birefringence) to 10􀀀4 (high birefringence), and for different MCF bending radii. It is also shown that the mean ICXT power estimates obtained with the CLMT and DP-DCM are very similar. Furthermore, using the CLMT, the PDFs of the ICXT power of the polarization directions are shown to be chi-squared distributions with two degrees of freedom, and the PDF of the sum of the ICXT power of the polarizations is shown to follow a chi-squared distribution with four degrees of freedom.

Paper Nr: 22
Title:

Titanium Dioxide based Electrochromic Iris - Preparation, Characterization and Application

Authors:

C. Kortz, A. Hein and E. Oesterschulze

Abstract: The miniaturization of a classical iris consisting of blades which are moved towards the path of light is limited, due to the size of the actuators and the additional space needed for blade storage when the iris is completely open. To overcome these limitations we present a fast switching, non-mechanical micro iris based on electrochromic molecules, namely viologens, which are adsorbed onto a titanium dioxide nanoporous electrode. Measurements of the energy consumption, the response time and the spectral light transmission are presented. The complete fabrication route and the life time of the device are discussed in detail.

Paper Nr: 23
Title:

Photonic Sensing and Characterisation of Multiphase Water Flows - Computational Sensing and Imaging

Authors:

Sergio L. Carrasco-Ortiz, Eduardo Valero, Maria Morant and Roberto Llorente

Abstract: This paper presents and demonstrates experimentally a photonic sensor based on laser excitation and CMOS array detection of light interactions in a bubbling water column. Bubbling water columns are multiphase water flows, which can be produced by cavitation effect in screws and pump-jets, or by water-air mixing in the dam intakes and spillways in hydroelectric energy generation plants. The proposed optical sensor comprises a CMOS array with a polymeric tuneable optical lens sampling the area illuminated by a diode laser operating at 532 nm. By computational imaging, the sensor is able to measure the size, shape and speed of the bubbles inside the water column and the corresponding bubble concentration. The developed laser-assisted sensor is demonstrated experimentally in the laboratory with a water column at 0.05 MPa with good results employing Optical Flow, SIFT and SURF computational methods.

Paper Nr: 39
Title:

Impact of Inter-core Crosstalk on the Performance of Multi-core Fibers-based SDM Systems with Coherent Detection

Authors:

Bruno R. P. Pinheiro, João L. Rebola and Adolfo V. T. Cartaxo

Abstract: Inter-core crosstalk (ICXT) can limit the multi-core fiber (MCF) systems performance and transmission reach. Over the last years, the impact of the ICXT on the performance of MCF optical communication systems with coherent detection has been investigated in several works. However, the influence of the MCF parameters and transmitted signal characteristics on the ICXT mechanism and the degradation induced by it on the performance of coherent detection MCF systems are still to be completely assessed. In this work, the impact of the ICXT on the performance of coherent detection MCF-based transmission systems is assessed through numerical simulation considering fiber linear propagation. The metrics used to assess the MCF system performance are the bit error rate (BER) and the optical signal-to-noise ratio (OSNR) penalty due to the ICXT. Our results show that the BER and the OSNR penalty due to the detected ICXT, in MCF-based systems with coherent detection, are influenced by the skew, time misalignment between the transmitted signals and the roll-off factor of the transmitted signals. In the range of skew and roll-off factors analyzed, the maximum reduction of maximum ICXT level for a 1 dB OSNR penalty by appropriate choice of skew and roll-off factor does not exceed 1.7 dB.

Paper Nr: 54
Title:

High-Dynamic and High-resolution Automatic Photon Counting OTDR for Optical Fiber Network Monitoring

Authors:

Felipe Calliari, Luis E. Y. Herrera, Jean Pierre von der Weid and Gustavo C. Amaral

Abstract: In this work, the development of a hybrid structure for the monitoring of optical fibers, using two types of Photon Counting Optical Time Domain Reflectometers (n-OTDR), is presented. While one n-OTDR presents a 32 dB dynamic range with spatial resolution of 6 m and minute-range measurements, the other has a 14 dB dynamic range and a resolution of 3 cm with hour-range measurements. By employing a trend filter capable of detecting fiber faults in the n-OTDR fiber profile and interchanging between either OTDR techniques in an automatic fashion, we were able to harness the qualities of both in the minimum amount of measurement time. Our experimental results performed with multiple optical fiber links attest the structure’s capability of automatically detecting faults in an optical fiber link with ultra-high-resolution and minute-range measurements. Furthermore, tunability of the hybrid structure enabling the monitoring of wavelength-division multiplexed optical networks has been demonstrated.

Paper Nr: 56
Title:

The Role of a Discontinuous Free-Electron Density in Harmonic Generation from Metal Surfaces

Authors:

Michael Scalora, Maria Vincenti, Domenico de Ceglia, Neset Akozbek, Mark Bloemer, Jose Trull and Crina Cojocaru

Abstract: We discuss a dynamical model of harmonic generation that arises from surfaces that demarcate regions of discontinuous free electron densities. These circumstances can arise from a simple metal mirror, to more complex structures such as layered structures composed of different metals or a metal and a conducting oxide. Using a modified hydrodynamic model we examine the simple case of a metal mirror, assuming the surface is characterized by an electron cloud that spills out into vacuum and shields the internal portions of the remaining medium. We also assess the relative importance of additional nonlinear sources that arise when a free electron discontinuity is present, and show that under the right circumstances both second and third harmonic generation can be very sensitive to the nature, density and thickness of the free electron cloud. Our findings suggest the possibility to control surface harmonic generation through surface charge engineering.

Paper Nr: 71
Title:

High Peak Power Er-doped Tapered Fiber Amplifier

Authors:

M. M. Khudyakov, A. E. Levchenko, V. V. Velmiskin, K. K. Bobkov, D. S. Lipatov, A. N. Guryanov, M. M. Bubnov and M. E. Likhachev

Abstract: A novel tapered Er3+-doped fiber design for high peak power amplification has been developed and tested. The fiber core was based on P2O5-Al2O3-SiO2 glass matrix, which allowed simultaneous achievement of low NA and high Er content. The core diameter was changing along the fiber length from 22.5 µm (single-mode operation) to 86 µm along 2.5 meters. Amplifier based on counter propagation signal (coupled to the thin tapered fiber end) and pump (coupled into thick fiber end) was developed and a nearly diffraction-limited beam quality (M2<1.27) of the output signal has been achieved. Amplification of 80 ns single frequency Gaussian-shaped pulses has resulted in peak power of 20 kW in 55 ns pulses (1.5 mJ) limited by available pump power.

Short Papers
Paper Nr: 3
Title:

A New Technique for Phase Shift Measurements based on Amplitude Estimations

Authors:

Tatiana Yakovleva

Abstract: The paper presents a new original technique for the accurate real time measuring of the phase shift between two quasi-harmonic optical signals based upon the estimation of amplitudes of the both initial quasi-harmonic signals and the third signal that is formed by summation the first two ones. The required phase difference is then calculated as an angle of a triangle formed by the reconstructed undistorted signals’ amplitudes values. An important peculiarity of the proposed technique consists in the fact that the phase data are obtained as a result of the amplitude measurements only what significantly decreases the demands to the measuring equipment. For the amplitude values estimation the methods of the Rician data analysis are proposed to be applied. The paper provides both the mathematical substantiation of the technique and its computer simulation results. The elaborated method is meaningful for various applied tasks to be solved in numerous ranging and communication systems.

Paper Nr: 5
Title:

Identifying Isolated Glioblastoma Tissues in Human Patients through Their Optical and Spectral Properties

Authors:

Hussein Mehidine, Fanny Poulon, Ali Ibrahim, Marjorie Juchaux, Pascale Varlet, Bertrand Devaux, Johan Pallud and Darine Abi Haidar

Abstract: Survival rates and health-related quality of life of adult patients suffering from glioblastoma depend significantly on the extent (no residual tumor tissue) and precision (no collateral damage) of the surgical resection. Assistance in defining the borders of the infiltrating component of the glioblastoma would be valuable to improve outcomes. A tissue can be defined by its optical properties : absorption, scattering, intensity of fluorescence, that will give a unique signature. In this work we look at the absorption and scattering coefficients of glioblastoma and control tissues from adult patients using an integrating sphere, spectral measurements were also took on the samples using a fiber endoscope. The preliminary results show the potential of using endogenous fluorescence for intraoperative identification of residual glioblastoma tissue in the wall of the surgical cavity of resection.

Paper Nr: 11
Title:

Characterization of High Speed Optical Detectors for Purpose of OM4 Fibre Qualification: Selective Mode Detection

Authors:

F. J. Achten and D. Molin

Abstract: The most important characterization of OM4 fibre is the ‘Differential Mode Delay’ (DMD) measurement. The measured DMD profile is some kind of ‘roadmap’ of the OM4 fibre; it contains all relevant data from which the main optical parameters are computed (for instance ‘Effective Modal Bandwidth’). Most requirements for the measurement equipment are well defined within standardization documents. However the requirements for the detector are still under discussion. This paper shows the state of the art of commercially available detectors (high speed optical electrical converters, fibre coupled) from different manufacturers. A method to characterize these detectors is suggested, and it shows the ‘ideal’ detector is not yet commercially available.

Paper Nr: 14
Title:

Resonant Tunnelling and Optical-mechanical Analogy - Overcoming of Blackout Problem

Authors:

Anna Bogatskaya, Nikolay Klenov and Alexander Popov

Abstract: We report on using the optical mechanical analogy to study the propagation of the electromagnetic wave in through the plasma layer surrounding the hypersonic object moving in dense gaseous medium. This analogy allows us to consider plasma sheath surrounding the object as a potential barrier and analyse the process of electromagnetic wave tunneling. The idea is to embed a dielectric layer as a «resonator» between the surface of the object and plasma sheath which is supposed to provide an effective tunneling regime. We discuss the peculiarities of optical mechanical analogy applicability and analyse the radio frequency wave tunnelling regime in detail. The cases of normal and oblique incidence of radiofrequency waves on the vehicle surface are studied. The analysis is applied for a problem of overcoming of the communication blackout during the hypersonic vehicle re-entry into the Earth's atmosphere.

Paper Nr: 26
Title:

Tapered Fibre Optic Biosensor (TFOBS) by Optically Controlled Etching for Label-Free Glucose Concentration Monitoring - Biomedical Optics

Authors:

Sergio Mena, Maria Morant, Juan Hurtado and Roberto Llorente

Abstract: This paper proposes, designs and demonstrates experimentally a tapered fibre optic biosensor (TFOBS) fabricated by an optically controlled HF chemical etching. The fabricated device is demonstrated to operate properly as a label-free sensor for glucose concentration detection. This work presents a novel fabrication method of a single-mode TFOBS controlling the reaction rate by changing the HF concentration and monitoring the optical power variation at the fibre output. Two TFOBS fabricated with different cladding diameters are evaluated experimentally to sense different glucose concentrations observing the changes in the refractive index of the medium in various solvents. The sensing capabilities are evaluated by modal interferometry measurement of both intensity and phase variations of the received optical signal.

Paper Nr: 27
Title:

Mueller Optical Coherence Tomophraphy Technique for Non-Invasive Glucose Monitoring

Authors:

Tseng-Lin Chen, Quoc-Hung Phan and Yu-Lung Lo

Abstract: A new and novel technique for non-invasive (NI) glucose sensing based on Mueller optical coherence tomography (OCT) technique is proposed. The feasibility of the proposed technique is demonstrated by detecting the optical rotation angle and depolarization index of phantom solution containing de-ionized water (DI), glucose solutions with concentrations ranging from 0~4000 mg/dL and 0.02% lipofundin. The practical applicability of the proposed technique is demonstrated by measuring the optical rotation angle and depolarization index properties of the human fingertip of normal healthy volunteers.

Paper Nr: 30
Title:

Benchtop Mini Preform Fabrication for Specialty Optical Fibers

Authors:

W. J. Lai, L. Zhang, V. J. J. Yeo, D. J. M. Ho and C. H. Tse

Abstract: We propose and demonstrate a benchtop version of the mini preform and hence short length fiber fabrication system. The system is compact, low cost, fast and flexible compared to the standard fabrication systems. We mimic the recipe used in standard Modified Chemical Vapour Deposition (MCVD) preform fabrication process. Incorporating with solution doping technique, we have fabricated several short length rare earth doped silica fibers, including Ytterbium and Erbium. The results obtained serve as a good indication on the composition of the rare earth elements to be used in the standard processes. The technique is promising and suitable for rapid specialty optical fiber prototyping.

Paper Nr: 40
Title:

Holographic Real-time Image Projection with Data Compression

Authors:

Paula Adrianna Kochanska, Michal Makowski, Izabela Ducin, Karol Kakarenko, Jarosław Suszek and Marcin Bieda

Abstract: Computer-generated holography is a technique of forming images using spatial light modulators. One of its applications is real-time holographic projection. This method is very resource-consuming, as it requires calculating the hologram using numerical methods (FFT), which is why it can’t be sufficiently executed on mobile devices. The idea to overcome this problem is to perform calculations on remote servers (in the cloud). However, currently there is no good method of data compression, which makes the transmission inefficient. In this paper we present new approach to holographic data compression which was implemented in real-time holographic transmission with on-the-fly data compression and projection in colour between computers in Poland and Japan. Two algorithms, which implement bitplanes extractions are discussed.

Paper Nr: 48
Title:

Nonlinear Trapping and Interfering Modes in a Quasi-One-Dimensional Microcavity Laser

Authors:

Maciej Pieczarka, Christian Schneider, Sven Höfling and Grzegorz Sęk

Abstract: Experimental studies of the emission from one-dimensional microcavity laser structure under nonresonant optical excitation are presented. The one-dimensional laser was prepared by electron-beam lithography and reactive ion etching from a planar microcavity sample. Below the lasing threshold, the system was in the strong coupling regime, where the emission exhibits the common exciton-polariton far-field dispersion. Above the threshold, the system switched to the weak coupling regime and the photon lasing was observed. Interestingly, under higher pumping powers above the threshold, a strong blueshift of the lasing mode was observed, with localisation of the far-field emission at finite wavevectors. The near-field images showed interference fringes corresponding to the interference of propagating modes in k-space. This is interpreted in terms of self-interfering modes confined between the pumping spot and the edges of the 1D microlaser.

Paper Nr: 49
Title:

LIBS based Tissue Differentiation for Er:YAG Surgical Laser

Authors:

Fanuel Mehari, Benjamin Lengenfelder, Robert Figura, Florian Klämpfl and Michael Schmidt

Abstract: The analytical technique laser-induced breakdown spectroscopy (LIBS) is becoming an attractive technique in the field of medicine. One emerging application is the differentiation of biological tissues in real-time during laser surgery. This work attempts to further investigate the use of LIBS together with a surgical Er:YAG laser. The main goal here is to investigate the effect of body fluids as potential contaminants during LIBS based differentiation of soft tissues. Furthermore, the work attempts to exploit the use of the surgical laser as a cleaning laser and compares the effect when only the LIBS laser is used for tissue differentiation. The study shows that body fluids have a significant influence on the LIBS spectra and that a surgical laser might serve as an in-vivo cleaner leading to improved tissue classification during laser surgery.

Paper Nr: 51
Title:

Development of Mid-IR Fiber Bundle for Thermal Imaging

Authors:

Andrea Ventura, Joris Lousteau, Fedia Ben Slimen, Nicholas White and Francesco Poletti

Abstract: We present and discuss the fabrication and characterization of a Mid-Infrared (Mid-IR) transparent flexible bundle based on 1200 fibers whose cores consist of a Ge30As13Se32Te25 chalcogenide glass and the cladding of a Fluorinated Ethylene Propylene (FEP). The Mid-IR fiber bundle was manufactured using the stack and draw method. The high index contrast between the glass and the cladding allows for strong field confinement of the well guided modes within the chalcogenide glass core transparent across the Mid-IR. Higher order modes, which could be prone to cross talk, suffered high losses thanks to the high attenuation offered by the polymer cladding. Additionally, the FEP cladding confers the bundle mechanical flexibility. Following a qualitative thermal imaging assessment, we also present and discuss the experimental loss measurements of the fiber bundle and we compare them to values obtained through modelling to conclude on the potential prospect of the manufactured bundle and its possible improvements.

Paper Nr: 60
Title:

Hyperspectral Compressive Sensing Imaging via Spectral Sparse Constraint

Authors:

Qi Wang, Hong Xu, Lingling Ma, Chuanrong Li, Yongsheng Zhou and Lingli Tang

Abstract: The existing algorithms to reconstruct hyperspectral compressive sensing images mainly use the sparse property of spatial information and some simple non-adaptive spectral constraint such as the low-rank property. However, these strategies cannot remove the spectral redundancy efficiently and a new method to make full use of the abundant redundancy of spectral information and improve the quality for hyperspectral CS reconstruction is necessary. A new CS sampling and reconstruction model based on spectral sparse representation was proposed in this paper. The spectral sparse dictionary was constructed from training samples to enhance the effect of sparse representation and the total variation constraint of spatial images was also considered to further enhance the precision during the reconstruction. The experiment to reconstruct AVIRIS hyperspectral images of 200 bands show that the hyperspectral image was almost perfectly reconstructed at 25% sampling rate and the spatial and spectral precision was higher than traditional methods which only adopt the spatial sparsity and simple non-adaptive spectral constraint in the same condition.

Paper Nr: 67
Title:

Fredholm Integral Equation for Finite Fresnel Transform

Authors:

Tomohiro Aoyagi, Kouichi Ohtsubo and Nobuo Aoyagi

Abstract: The fundamental formula in an optical system is Rayleigh diffraction integral. In practice, we deal with Fresnel diffraction integral as approximate diffraction formula. We seek the function that its total power is maximized in finite Fresnel transform plane, on condition that an input signal is zero outside the bounded region. This problem is a variational one with an accessory condition. This leads to the eigenvalue problems of Fredholm integral equation of the first kind. The kernel of the integral equation is Hermitian conjugate and positive definite. Therefore, eigenvalues are nonnegative and real number. By discretizing the kernel, the problem depends on the eigenvalue problem of Hermitian conjugate matrix in finite dimensional vector space. By using the Jacobi method, we compute the eigenvalues and eigenvectors of the matrix. We applied it to the problem of approximating a function and evaluated the error.

Paper Nr: 72
Title:

Constrained Coding for Hardware-friendly Intensity Modulation

Authors:

Gilbert J. M. Forkel, Tom J. Wettlin and Peter A. Hoeher

Abstract: An advanced signal design for boosting the performance of binary-modulated IM/DD communication systems is presented. Multiple light sources are jointly modulated so that the optical signals superimpose at the receiver. The superimposed signal is of high rate. The switching sequences are constrained to match the physical properties of the transmit hardware. A graph-based representation is used to design a low-complexity block code, enabling the use of the binary superposition modulation scheme under investigation in a practical IM/DD setup. Based on this coded signal design measurement results on power consumption and simulation results on bit error rate performance are presented.

Posters
Paper Nr: 21
Title:

Pixel Apodization for the Suppression of Higher Diffractive Orders in Computer Holography

Authors:

Joanna Starobrat and Michal Makowski

Abstract: Demand for a next generation of head-up displays have increased the demand for the applicable holographic displays. From the available spatial light modulators (SLM), Liquid Crystal on Silicon (LCoS) SLMs are the most popular for the simplicity of addressing and their relatively low costs. However, improving its efficiency demands reduction of higher diffraction orders. In this work we propose a new solution, that is the pixel apodization as the means to redirect the light intensity from the undesirable images to the main image. The higher diffraction orders are the result of the rectangular shape of the pixels of the SLM, as it can be concluded from the Fourier Transform (FT) analysis. Hence we exploit the known property that a Gaussian function is, up to a constant multiple, its own FT. The presented simulations support the theoretical conclusions, as the apodization allows for a significant lowering of the intensity of the third and higher diffraction orders, in the same time increasing the intensity directed to the main image.

Paper Nr: 32
Title:

Diluted Chemical Identification by Total Internal Reflection Photonic Sensing - Biomedical Optics

Authors:

Eduardo Valero, Sergio L. Carrasco-Ortiz, Maria Morant and Roberto Llorente

Abstract: A novel optical sensor architecture for the rapid identification of liquid samples is proposed and evaluated experimentally. The proposed architecture is based on total internal reflection transmission of a laser beam. A CMOS sensor is used to acquire the reflection produced by a narrow laser beam when interacting with the liquid sample on the surface of an equilateral prism. Using digital image processing techniques, the critical angle of the transmission is calculated and the identification of the refractive index of the liquid sample is obtained. In the present work, distinct liquid substances were evaluated experimentally using a red He-Ne laser at 632.8 nm wavelength obtaining the refractive index with a deviation of less than 0.0014 from the value. Sensing by refractive index changes are of great importance in biomedical (e.g. optical diagnosis and laser treatments) and chemical applications.

Paper Nr: 34
Title:

Fast Photoelectric Estimation of Oxygen Transmissibility of Silicone Hydrogel Contact Lens

Authors:

Hsin-Yi Tsai, Chih-Ning Hsu, Yu-Hsuan Lin, Kuo-Cheng Huang and Patrick Joi-Tsang Shum

Abstract: Nominal oxygen transmissibility (Dk/t) values on commercial product packages are usually of the lens material instead of the actual values of contact lenses (CLs) derived based on their power. To evaluate the Dk/t values of CLs of different powers, we developed a rapid photoelectric method. In the experiment, a photodiode was employed to detect variations in the light intensity passing through silicone hydrogel (Si-Hy) CLs over a period. Light intensity variations can indicate the water content (WC) and power of Si-Hy CLs and help calculate the Dk/t of Si-Hy CLs of different powers. Experimental results indicated that the WC and specific power of Si-Hy CLs were determined by the initial attenuation voltage, which ranged from 0.73 to 1.15 V for the lenses tested herein, whereas the WC varied from 38% to 56%. The Dk/t of Si-Hy CLs at -3.00 D was determined from the voltage variation over 3 min after reaching the peak voltage and the Dk/t corresponding to a specific power could be evaluated from the ratio of initial attenuation voltage of a lens having a specific power to that having -3.00 D. The results of this study can serve as reference information for quality control in factories.

Paper Nr: 74
Title:

Laser Spectroscopy for Trace Matter Detection in Air

Authors:

T. Stacewicz, Z. Bielecki, J. Wojtas, P. Magryta and M. Winkowski

Abstract: The article describes implementation of absorption spectroscopy methods for construction of trace compounds sensors in air. Multipass spectroscopy with laser wavelength modulation as well as cavity ring down spectroscopy was applied. High detection limits and good selectivity sensors of nitrogen oxide, dioxide, carbonyl sulphide, ethane, ammonia, methane, carbon oxide, acetone and water vapour were elaborated. The sensors were used in experiments about security and environmental monitoring, human breath analysis as well as for the geophysical research.

Area 3 - Photonics

Full Papers
Paper Nr: 25
Title:

Miniaturized Surface Plasmon Resonance based Sensor System

Authors:

Peter Hausler, Christa Genslein, Carina Roth, Thomas Vitzthumecker, Thomas Hirsch and Rudolf Bierl

Abstract: We describe the miniaturization of the Surface Plasmon Resonance (SPR) technology which mainly finds its applications in pharmaceutical screening and biotechnology so far. SPR spectroscopy is a label-free, non-destructive and highly sensitive measurement principle detecting changes in the refractive index in striking distance to a gold surface. A transfer of this technology to a miniaturized sensor will broaden the range of possible applications. A promising feature which is included in the miniaturized system is the angle-dependent recording of the SPR signals without moving parts. Commercial SPR assays are mainly working with a small number of sensing spots. In contrast, the SPR imaging system shown here will allow to use an array of many sensing spots. In combination with chemical receptors designed as an artificial nose, the simultaneous detection of many analytes is envisioned for future applications.

Paper Nr: 55
Title:

Lithiumniobate Die Assembled by a Low-stress Soldering Technique - Method to Fasten a Surface Acoustic Wave Sensor

Authors:

Pol Ribes-Pleguezuelo, Katherine Frei, Gudrun Bruckner, Erik Beckert, Ramona Eberhardt and Andreas Tünnermann

Abstract: Solderjet bumping technique was applied to assemble a Surface Acoustic Wave (SAW) sensor prototype designed with a lithiumniobate crystal and a base sub-mount made of stainless steel. The assembly was designed with this technology in order to withstand the device’s mechanical strength requirements. The initial performed tests showed that the solderjet bumping technique can be used to assemble brittle components without creating internal damage in the crystal. The selected solder alloy Au80Sn20 used to fasten the lithiumniobate showed proper alloy wettability and joint strength on the crystal and on the substrate material. Finally, a lithiumniobate die device was soldered by soldering means to the stainless steel sub-mount, and withstood the strength device requirements by passing robustness (push) tests.

Short Papers
Paper Nr: 1
Title:

Highly Reliable, Cost-effective and Temperature-stable Top-illuminated Avalanche Photodiode (APD) for 100G Inter-Datacenter ER4-Lite Applications

Authors:

Jack Jia-Sheng Huang, H. S. Chang, Yu-Heng Jan, H. S. Chen, C. J. Ni, E. Chou, S. K. Lee and Jin-Wei Shi

Abstract: One of the key enablers for 100G ER4-Lite optical modules is 25G APD photodetector that can be employed in 30-40km optical links for inter-datacenter applications. In this paper, we demonstrate that a cost-effective top-illuminated InGaAs/InAlAs APD photodetector can be manufactured to meet stringent IEEE standard of 100G ER4-Lite. The 25G APD shows high bandwidth, high sensitivity with superb temperature stability of breakdown voltage. The APD photodetector also possesses excellent durability against harsh optical and electrical overload in both burst and continuous modes. Robust reliability performance based on aging conditions of 85-175°C has also been achieved with an activation energy of 1.18eV.

Paper Nr: 4
Title:

Dye-Sensitized Photoconductivity and Photovoltaic Effect in Silicon

Authors:

Mikhail A. Goryaev and Rene A. Castro

Abstract: In this paper we investigate the influence of organic dyes applied to the semiconductor surface on the effectiveness of the direct current photoconductivity of powdered silicon and photovoltaic effect in the monocrystalline silicon. Dyes on the semiconductor surface effectively increase the photoconductivity of powdered samples in the dye absorption band. The effectiveness of the monocrystal sensitization is smaller because the specific surface area of finely divided powders is several orders of magnitude larger than it is in monocrystals. The optimum concentrations of dye molecules on the semiconductor surface for the internal photo effect sensitization are determined. We also discuss the mechanism of the sensitization based on the theory of non-radiative resonant inductive energy transfer.

Paper Nr: 20
Title:

Photonics Defined Radio - A New Paradigm for Future Mobile Communication of B5G/6G

Authors:

Zong Baiqing, Zhang Xiaohong, Li Xiaotong, Wang Jianli and Zhang Senlin

Abstract: Photonics defined radio, a new and possibly standardized paradigm, is proposed, converging integrated coherent optics, integrated microwave photonics and photonic DSP, and expected to dominate the designs of future communication and sensing systems. The applications of photonics defined radio are also discussed in the next generation cloud-based radio access network (CloudRAN), sensing and communication integrated system, as well as artificial intelligence radio.

Paper Nr: 42
Title:

New Ga-Free InAs/InAsSb Superlattice Infrared Photodetector

Authors:

J-P. Perez, Q. Durlin, C. Cervera and P. Christol

Abstract: We studied Ga-free InAs/InAsSb type-II superlattice (T2SL) in terms of period, thickness and antimony composition as a photon absorbing active layer (AL) of a suitable XBn structure for full mid-wavelength infrared domain (MWIR, 3-5µm) detection. The SL photodetector structures were fabricated by molecular beam epitaxy (MBE) on n-type GaSb substrate and exhibited cut-off wavelength between 5µm and 5.5µm at 150K. Electro-optical and electrical results of the device are reported and compared to the usual InSb MWIR photodiode.

Paper Nr: 44
Title:

Highly Linearly Polarized Emission from Quantum Dash Excitons - Modelling and Experiment at the 3rd Telecom Window

Authors:

Paweł Mrowiński, Sven Höfling, Johannes P. Reithmaier and Grzegorz Sęk

Abstract: This work is focused on controlling the polarization anisotropy of emission from single self-assembled InAs/InGaAlAs quantum dashes grown by molecular beam epitaxy on InP substrate. We studied the degree of linear polarization of excitonic emission for submicrometer mesa photonic structures of asymmetric in-plane geometry. We present both experimental and numerical analysis performed at 1550 nm wavelength (3rd telecommunication window for optical fibers), and we discussed the impact of anisotropy of the dielectric confinement, which paves the way towards a single photon source characterized by a degree of linear polarization exceeding 0.9.

Paper Nr: 64
Title:

Design, Ion Beam Fabrication and Test of Integrated Optical Elements

Authors:

I. Bányász, S. Pelli, G. Nunzi-Conti, G. C. Righini, S. Berneschi, E. Szilágyi, A. Németh, M. Fried, P. Petrik, E. Agócs, B. Kalas, Z. Zolnai, N. Q. Khanh, I. Rajta, G. U. L. Nagy, V. Havranek, V. Vosecek, M. Veres and L. Himics

Abstract: Various methods, based on the use of ion beams, were used for the fabrication of planar and channel optical waveguides and Bragg gratings in optical crystals and glasses. Some examples of the results of these researches are presented in this review. Researches were initiated on ion beam fabrication of planar and channel optical waveguides in tellurite glasses. The ions used in the experiments were mainly helium, carbon, nitrogen and oxygen. In case of the two dimensional elements, like channel waveguides, both masked ion implantation and direct writing with ion microbeam were used. Optical microscopy (phase contrast, interference and interference contrast (INTERPHAKO), spectroscopic ellipsometry, m-line spectroscopy, Rutherford Backscattering and micro Raman spectroscopy were used to test the integrated optical elements.

Posters
Paper Nr: 36
Title:

Design and Optimization of High-Channel Si3N4 Based AWGs for Medical Applications

Authors:

D. Seyringer, A. Maese-Novo, P. Muellner, R. Hainberger, J. Kraft, G. Koppitsch, G. Meinhardt and M. Sagmeister

Abstract: We present the design and optimization of 80-channel, 50-GHz Si3N4 based AWG. The AWG was designed for TM-polarized light with a central wavelength of 850 nm. The simulations showed that, while the standard channel count AWGs (up to 40) feature gut optical properties and are relatively easy to design, increasing the channel counts (> 40 channels) leads to a rapid increase in the AWG size and this, in turn causes the deterioration of optical performance like higher insertion loss and, in particular, higher channel crosstalk. Optimizing the design we are able to design 80-channel, 50-GHz AWG with satisfying optical properties.

Paper Nr: 58
Title:

FDTD Modeling and Simulation of Organic Light Emitting Diode with Improved Extraction Efficiency using Moth-eye Anti Reflective Coatings

Authors:

B. M. Chaya, M. Venkatesha, Shruthi Neduri and K. Narayan

Abstract: In this work modeling of two dimensional fluorescence based bottom emitting Organic Light Emitting Diode (OLED) using Moth eye Anti Reflective Coatings (ARC) is presented. The Finite Difference Time Domain (FDTD) mathematical modeling has been used to analyze the light extraction efficiency from fluorescence based Organic Light Emitting Diode (OLED). The OLED structure has been simulated by using 2D Moth-eye Anti Reflective coatings. The Finite Difference Time Domain (FDTD) method is used to model and simulate the OLED structure. An enhancement of Light Extraction Efficiency (LEE) has been achieved by inserting Moth-eye Anti Reflective coatings on the surface of the glass substrate which reduces reflection and increases the transmission. Comparative study is carried out between hexagonal photonic crystals and Moth eye Anti reflective coatings by placing these nanostructures on the substrate of OLED. The improvement in the far field intensity of OLED structure is achieved by optimizing the angular distribution of light through the substrate with moth eye anti reflective coatings.