We demonstrate a high peak power and high burst energy linear-polarization, narrowband, GHz-adjustable burst-mode fiber-bulk hybrid laser with central wavelength of 1064 nm and its second-harmonic generation. The active modulated burst-mode seed provides the tunability of temporal parameters and the pre-compensation of burst envelope distortion. Three-stage polarization maintained fiber amplifier cascading

We present the machine learning inspired design of two types of GaN zero contrast subwavelength gratings (SWGs): a polynomial-shaped grating and, for reference, a conventional rectangular grating, using the differential evolution algorithm to optimize the designs for high broadband reflectivity and separately for large fabrication tolerance. Two wavelength regimes with 500 nm and 1.55 μm center wavelengths

A method to calibrate the errors of polarization information measured by division-of-focal-plane polarimeters is demonstrated. The principle of this method is explained, and its feasibility is verified by theoretical simulation and experiment. The simulation and experimental results show that this method can obviously improve the measuring precision of polarization information, and compared with other

The state-of-the-art optical coherence technology (OCT) has its limitation, such as bulky and quite expensive. Miniaturization and integration of the OCT system are promising to get a compact, less costly, and more stable device. In this paper, we report the influence of optical power splitting on the sensitivity and axial resolution in spectral-domain OCT (SD-OCT) on silicon chip using tandem Mach-Zehnder

Early stage cancer detection technologies can provide functional information and potentially decrease the mortality rate caused by cervical cancer. In our previous work, a miniaturized ultrasound and photoacoustic endoscopic system has been developed to image the cervical tissue through the cervical canal to fulfills the need for a safe, low-cost, and high-resolution functional diagnostic system. However

An optical approach for pigmented lesions detection in human skin is presented. As differences between normal skin tissue and pigmentation tissue (and even a change in pigmentation development) can be detected by their optical properties, this paper presents a new, potentially noninvasive approach for skin cancer detection. Since each wavelength has different penetration depth into the tissue and different

To advancement in security applications, for the first time, a bio-chaotic key generated from the emerging biometric trait “finger knuckle print (FKP)” has been proposed for data security and authentication. In the system, the feasibility to generate multiple keys from the single FKP image has been exploited to secure multiple information, which results in significant enhancement of the security strength

In this work, we propose and numerically investigate a scheme for reservoir computing (RC) based on two parallel reservoirs under identical electrical message injection, in which two semiconductor lasers (SLs) under optical feedback are utilized as two parallel reservoirs. For simplifying the system, only one mask signal is employed in this scheme. After multiplying with input data, the masked information

A 1/1.5 μm dual-band mode-locked fiber laser is experimentally demonstrated. The laser is based upon an architecture in which the 1 μm and the 1.5 μm signals are generated in independent cavities that share the identical active fiber. The mode-locking of the 1 μm laser is realized via nonlinear polarization evolution (NPE), whilst the 1.5 μm laser is mode-locked through cross-phase modulation (XPM)

We investigated room-temperature pulsed lasing in heavily doped Fe:ZnSe single crystals. The active elements were pumped by a Q-switched Cr 3+ :Yb 3+ :Ho 3+ :YSGG laser operating at 2.87 μm. Our results show that the generation of short laser pulses has a deep high-frequency modulation associated with relaxation dynamics in Fe:ZnSe. The lasing regime obtained in this study provides a straightforward

In this manuscript, a method of generating an ultra-long optical needle (depth-to-width ratio 37.5:1) is proposed and demonstrated by focusing an azimuthally polarized beam. In theory, the action mechanism between the incident beam and the amplitude modulation element, the spiral phase modulation element, the focusing lens were studied based on the Richards and Wolf's theory. The relationship between

In this work we report the results of high density multi-channel optical multiprobes with pitches of 25 ${\mu }\rm{m}$ and 50 ${\mu }\rm{m}$ that provide edge-coupling used for on-wafer parallel testing of photonic integrated circuits. The probes are fabricated in an oxynitride platform and test demonstrations were carried out of edge-coupled indium-phosphide based photonic integrated circuits (PICs)

In this work, we analyze the effects of the presence of waveguides in a wireless on-chip optical channel, which act as obstacles for the rays composing the propagating signal. The analysis has been performed numerically by using the FDTD method, and the simulation results have been validated by the experimental characterization. This work focuses on the relationship between the received signal and

In this study, the trajectory of a 90° bend is divided into two symmetric halves that are mirror images of each other as referenced to the symmetry axis at 45°, and each half is segmented into small curved sections. The bending radius and waveguide width for every section are parameters to be determined using a particle swarm optimization algorithm. The optimization is performed to maximize the transmission

The estimation of the degree of polarization of backscattered light and target light is the key to realize scattering removal in underwater polarimetric imaging. In this paper, a new polarization scattering removal method is proposed by realizing polarimetric calculation of the target light with each pixel of the scene automatically, which is conducive to the restoration of the details of underwater

In this paper, we demonstrate ultrastable radio-frequency (RF) transfer over long-haul optical fiber link. Our stabilized RF transfer technique is based on high-performance dual phase locked loops (dual-PLL) configuration which improves signal to noise ratio (SNR) of the round trip transmitted signals. At the local site, the frequency conversion phase-lock receiver (FCPLR) accomplishes high-quality

In this paper, a microfiber knot resonator (MKR) was encapsulated in polydimethylsiloxane (PDMS), and its capability to sense temperature was experimentally evaluated. A very high sensitivity of -12 nm/°C was recorded for the MKR device, with a microfiber diameter of 2μm and a ring diameter of 95 μm. However, light-loss was significant in the small MKR. We attribute this to the low ratio of ring-length

A novel photonic vector THz-wave signal generation at terahertz-wave (THz-wave) band by Mach Zendell modulator (MZM) -based optical frequency comb and in-phase and quadrature (IQ) modulator for signal modulation scheme is proposed. And we demonstrate 16 quadrature-amplitude-modulation (QAM) vector THz-wave signal generation and transmission by simulation. The IQ modulator is driven by a 2-Gbaud/3-Gbaud

In this paper, we propose a novel 3-dimension multi wings chaotic encryption scheme for PAM-DMT-based optical wireless access network. In our proposed scheme, one dimension (x) is used for XOR operation, one dimension (y) is used for confusion of PAM signal's amplitude and one dimension (z) is use for DMT subcarrier scrambling. We experimentally demonstrate the 3-dimension multi wings chaotic encryption

Carrier velocity modulation by asymmetrical concave quantum barriers to improve the performance of AlGaN-based deep-ultraviolet light emitting diodes has been investigated. The concave structure is realized by inserting a low Al composition AlGaN layer in the barrier, and thus forming a concave region on energy band. The measured device performance shows a significant improvement under 0–250 mA operation

We report the first experimental observation, to the best of our knowledge, of soliton molecules in a robust all polarization-maintaining (PM) mode-locked fiber laser with a nonreciprocal phase bias that results in a low self-starting threshold and stable mode locking. Through elaborately tuning the waveplate in the cavity, calibrating the laser pulse from conventional soliton to soliton molecules

To protect image information security, we propose an encryption algorithm based on chaotic sequences and bits' cross-diffusion. First, two chaotic sequences are generated by two-dimensional logic-sine coupling mapping, and the original image is scrambled with the two sequences. Secondly, the scrambled image is transformed into a one-dimensional sequence, and the low-order bits between every two pixels

In this work, by utilizing ionic liquid as the gain medium solvent, which is a new category of materials, we demonstrated a droplet-based dye laser system in a co-flowing microfluidic device. We characterized the droplet laser system and achieved a lasing threshold of 40.1 μJ/mm 2 . Owning to the unique properties of ionic liquids, such as negligible vapor pressure and good thermal and chemical stability

We demonstrate experimentally an optoelectronic oscillator (OEO) in which high side-mode suppression is achieved by cascading a phase modulator-based single passband tunable microwave photonic (MWP) filter with an optoelectronic feedback loop-based infinite impulse response (IIR) MWP filter. The OEO provides an RF oscillation that can be tuned from 6.5 GHz to 17.8 GHz with a phase noise lower than

We propose and numerically demonstrate the generation of wideband millimeter-wave (mmW) flat chaos with controllable power spectrum by injection of chaotic signal from external cavity semiconductor laser (ECSL) into optical time lens with noise phase modulation. Simulation results indicate consistent elimination of the ECSL relaxation oscillation frequency domination over the RF spectrum for large

We propose and demonstrate a 100 Gbit/s silicon photonic (SiPh) coherent receiver (Rx) with advanced digital signal processing (DSP) for dual-polarization quadrature-phase-shift-keying (DP-QPSK) transmission. It employs integrated 2D polarization-splitting grating couplers (2D-GCs), modified hybrid mixers and high speed silicon-germanium (SiGe) photodiodes (PDs). The 2D-GC replaced the polarization

Reconfigurable photonic technology combining multiple functionalities in a single gain-chip is a crucial light-based platform for enabling hybrid applications. Here, we report on achieving a widely tunable and reconfigurable blue laser source using a single-port gain medium based on an InGaN/GaN superluminescent diode (SLD). As compared to tunable laser-diode emitters based solely on stimulated emission

In this paper, a design of a silicon mode (de)multiplexer based on cascaded counter-tapered couplers is proposed and investigated. By using the particle swarm optimization algorithm and finite difference time domain method, structural parameters of each counter-tapered coupler in our proposed mode (de)multiplexer are optimized so that high conversion efficiencies can be obtained and coupling lengths

In this paper, we experimentally demonstrate a 450-nm laser underwater optical wireless transmission system, in which a comprehensive investigation is made to show the significant performance improvement of the discrete Fourier transform spread discrete multi-tone (DFT-S DMT) as compared to the conventional quadrature amplitude modulation discrete multi-tone (QAM-DMT) modulation. DFT-S DMT outperforms

All-dielectric metasurfaces offer unconventional optical functional behaviors for manipulating light, due to the strong localization of light with negligible dissipative loss. Here, we propose a compact design for a light emission cavity consist of an all-dielectric grating reflector and an all-dielectric symmetry-breaking metasurface supporting “dark” mode. The “dark” mode of the asymmetric metasurface

The optical properties of nonpolar AlGaN multiple quantum wells (MQWs) emitting at 280 nm were investigated intensively using temperature-dependent and time-resolved photoluminescence spectra associated with the characterization of structural properties. The densities of superficial pits and basal-plane stacking faults (BSFs) were reduced by 33.8% and 35.9%, respectively, for nonpolar AlGaN MQWs due

Recent advancements in photonic-electronic integration push towards denser multichannel fiber to silicon photonic chip coupling solutions. However, current packaging schemes based on suitably polished fiber arrays do not provide sufficient scalability. Alternatively, lithographically-patterned fused silica glass interposers have been proposed, allowing for the integration of fanout waveguides between

A broadband and compact TE-pass/TM-stop polarizer is presented based on hybrid plasmonic grating (HPG) on an x-cut Lithium-Niobate-on-isolator (LNOI) platform. By comprehensively analyzing the effects of metal width on mode effective index, mode similarity, and mode conversion, we demonstrate the structure with a narrow metal layer. The simulation results indicate that the polarizer with a compact

Surgeons need surgical navigation and intraoperative imaging for accurate surgery. However, current clinical surgical navigation systems have many drawbacks, including the need of fiducial markers, the lack of real-time registration update, and lack of functional imaging. We have developed a novel Real-time Fluorescence Imaging Topography Scanning (RFITS) system that delivers simultaneous real-time

A method to get balanced output power of a current-controlled in-line semiconductor laser based on REC technique is investigated. By mapping the contour lines of the P-I contour diagram of this in-line tunable laser into the wavelength-current contour map, the maximum output power and the tuning curve is obtained. Numerical studies are carried on under linear and quadratic relations, as well as an

We report on the characterization and analysis of a GaN-based distributed feedback laser diode (DFB-LD) with 3 rd -order laterally etched sidewall gratings centered at a wavelength of 420 nm. We also compare the device parameters with two commonly used Fabry-Perot (FP) devices operating at 450 nm and 520 nm. Intrinsic properties of the devices were extracted, including damping factor, carrier and photon

Structured illumination microscopy (SIM) is one of the most powerful and versatile super-resolution methods due to its live-cell imaging ability of subcellular structures with high speed. In this paper, we propose an alternative SIM assisted by Bloch surface wave (BSW). Through replacing the conventional laser interference fringes with sub-diffraction BSW counterparts with higher spatial frequency

Light field manipulation is an important technology for improving system-level efficiency of optical wireless power transfer (OWPT). In this paper, we propose and compare the Gerchberg-Saxton algorithm, direct binary search and genetic algorithm enabled light field optimization for adapting photovoltaic cells in different geometric arrangements. Under static condition, photoelectric conversion efficiency

The coexistence of double Fano interference originating from anti-phased and in-phased lattice resonances is observed in a novel plasmonic lattice array, which being consists of a horizontal double-stacked rectangular metal-insulator block. Based on a classic model analysis of coupled harmonic oscillators, the observed double Fano interference is revealed as a result of the interaction between a bright

A high-performance Bloch surface wave (BSW) sensor based on the hollow fiber (HF) inner coated with the one-dimensional photonic crystal (1DPC) consisting of TiO 2 and SiO 2 bilayers is proposed. Performances including sensitivity and figure of merit (FOM) of the sensor are investigated theoretically with the ray transmission model. Several structure parameters such as the center wavelength of 1DPC

We propose and demonstrate a cost-effective liquid refractive index (RI) sensor in polymer materials by employing a Mach-Zehnder interferometer (MZI) formed with the conventional strip waveguide. The proposed sensor can attain high sensitivity by choosing a suitable reference arm length to reduce optical path difference (OPD) between the two arms of the employed MZI. Our fabricated devices, which have

We presented a machine learning-based method to recognize suspension by distinguishing dispersoid-dependent speckle patterns using a convolutional neural network. The dispersoid size and concentration-related transmissive speckle patterns were recorded by a lensless camera when a coherent He-Ne laser irradiated the suspension. Firstly we realized the recognition of the polystyrene microspheres-dispersed

Non-contact, cost-efficient, and long-range precision metrology is essential for applications in diverse areas, from 3D sensing and robotics to automated manufacturing, and multiwavelength interferometry is a compelling candidate. Here, we present a new arithmetic approach for multiwavelength phase unwrapping, with the maximum theoretical range and tolerance to measurement noise in phase. We supplement

A CS 2 -filled Er-doped fiber, which can provide high nonlinearity and gain, low and flat all-normal dispersion profile, low loss and single-mode operation in the wavelength range of 1500–2500 nm, is proposed and analyzed by numerical simulation. When the 1900-nm 0.1-ps initial pulse with a peak power of 30 kW is injected into the active fiber, the generated supercontinuum (SC) spectrum has a double-hump

This paper proposes a novel return light cancellation technique using an adaptive interference equalizer in the wavelength division multiplexed passive optical network (WDM–PON) transmission system employing the single-wavelength bidirectional transmission scheme. In this scheme, the same wavelength is assigned to both the uplink and the downlink. In other words, the number of the wavelengths allocated

Self-homodyne optical orthogonal frequency division multiplexing (OFDM) transmission system is a variant of self-coherent systems with a relaxed laser linewidth requirement as opposed to a full coherent system. The system is designed by transmitting a carrier together with the subcarriers, ensuring a strong phase-correlation between them at a receiver compared to the coherent system where only the

Polarimetry in the far ultraviolet (FUV) is a powerful tool in many applications such as UV/EUV ellipsometry, characterization and control of the beam polarization status in large scale facilities and solar physics. FUV polarizers are among the most difficult components to manufacture, mainly due to the lack of dichroic and transparent materials in this spectral range. Although many different solutions

To verify the feasibility of Brillouin optical time domain reflector (BOTDR) applied in space station, three kinds of commercial fibers, YOFC fiber (about 1 km), Corning fiber (about 1 km) and Fujikura fibers (about 1.5 km), have been radiated by Co 60 in radiation experiment. Based on the Brillouin Gain Spectrum (BGS) along sensing fiber, we analyze power curve of Brillouin backscattered light, Brillouin

A novel photonic scheme of binary modulated microwave signals generation based on a dual-polarization quadrature phase-shift keying (DP-QPSK) modulator is proposed and experimentally demonstrated. The scheme is highly reconfigurable, amplitude keying signal (ASK), phase-shift keying signal (PSK) or frequency-shift keying (FSK) signal can be generated by appropriately setting the amplitude of the binary

In this paper, we study the thermal dissipation of Raman fiber laser and amplifier utilizing pure passive fiber as gain medium for the first time. Take into account the convective and conductive heat transferring process in the fiber, we consider the heat transferring and Raman conversion model based on the thermal conduction equations and the Raman coupled equations in the fiber. With the simulation

Highly nonlinear multimode optical integrated devices hold great promise for the emerging large-capacity mode division multiplexing (MDM) technology, and they correspondingly enable multimode optical signal processing at nodes of the MDM network. Here, we propose a highly nonlinear multimode organic-silicon slot waveguide (HN-OSSW) whose nonlinearity is greatly improved by the intensive optical field

Micro- and nanoscale photonic structures and devices play important roles in the development of advanced biophotonic systems, in particular, implantable light sources for optogenetic stimulations. In this paper, we numerically investigate silicon (Si) photonics based microprobes that can achieve multi-site, multi-spectral optical excitation in the deep animal brain. On Si substrates, silicon nitride

Reflection spectra based on guided-mode resonance (GMR) are simulated and discussed with transformation between one-dimensional (1-D) and two-dimensional (2-D) photonic lattices by introducing intermediate structures consisting of vertically-stacked 1-D and 2-D gratings. Dependences of reflection spectra on a 2-D fractional ratio are investigated for two examples of narrowband and broadband resonance

Integrating multiple functionalities into one single device is of great importance for ever-growing demand of photonic device. Optical vortex beam contains orbital angular momentum (OAM) and spin angular momentum (SAM) associated with phase and polarization singularities respectively, which has contributed to various application including optical manipulation, optical trapping and high-speed optical

The effects of the jet engine turbulence on a Gaussian Schell-Model (GSM) beam array propagating in a jet engine plume are studied theoretically. The analytical expressions of the cross-spectral density (CSD) function, the spectral degree of coherence (DOC) and the mean-squared beam width for a GSM beam array propagating through a jet engine plume region are derived based on the extended Huyens-Fresnel

We have proposed and experimentally realized an ultra-compact and broadband silicon nitride edge-coupler that enables high coupling efficiency. The proposed coupler was realized by concatenating short tapers in four stages, whose angles were designed to minimize the footprint while preserving the coupling efficiency. The constituting taper segments were designed by carefully sectioning a long adiabatic

By using the quadratic spatial filtering (QSF) operation of interferograms, we propose a fast and accurate phase retrieval algorithm in 2-step phase-shifting interferometry (PSI), in which both the interference signal separation and blind phase shift estimation can be realized. Compared with the existed 2-step PSI algorithms, the proposed QSF algorithm reveals two advantages: First, when the background

Assuming weakly guiding approximation, we examine orbital angular momentum (OAM) mode mixing on account of ellipticity in a fiber and derive a complete set of analytic expressions for spatial crosstalk, using scalar perturbation theory that incorporates fully the existing degeneracy between a spatial OAM mode and its degenerate partner characterized by a topological charge of opposite sign. These expressions

In this research, we present and study an erbium fiber laser with triple-fiber-ring (TFR) scheme for continuous-wave (CW) wavelength-selection. The designed TFR not only can achieve single-longitudinal-mode (SLM) oscillation, but also can spread the tuning range from 1519.0 to 1583.0 nm covering C- and part of L-bands. Moreover, 0 dB power fluctuation can be obtained from 1523.0 nm to 1559.0 nm for

This paper presents aproposal of a new optical multi-context blind scrubbing that can not only increase the soft-error tolerance of the configuration memory of field programmable gate arrays (FPGAs) but also support high-speed dynamic reconfiguration suitable for accelerating FPGA operations. The optical multi-context blind scrubbing operation uses a holographic memory as a soft-error free radiation-hardened