We demonstrate Zn-diffusion 940 nm VCSELs, which exhibits high-power (6.8 mW), highly single-mode (SMSR>50 dB) performances over the full range of bias currents. A wide -3-dB E-O bandwidth (18 GHz) and a short rise/fall time (20/11 ps) can also be achieved simultaneously.
We demonstrate through simulation the excitation of guided modes on a gold waveguide by a perpendicularly oriented Si3N4 waveguide. We can achieve 55% coupling efficiency for a 70 nm Au nanowire, and the ability for mode selection on larger Au nanowires supporting multiple modes.
We investigate the coupling performance between conventional silicon strip (Aeff ~ 0.06 µm2) and novel ultra-low mode area V-groove waveguides (Aeff ~ 0.005 µm2) in a directional coupler configuration. We find high peak coupling efficiencies and examine fabrication tolerances and operating bandwidth.
A nanolaser using AlGaAs nanodisk is theoretically demonstrated based on anapole state. The radius and height of the nanodisk are optimized to be 240nm and 120nm through geometry tuning based on Mie scattering theory. We have achieved near-field lasing at 1017nm with linewidth around 3.5nm.
We proposed a temperature sensor by selectively infiltrating refractive index liquid (RIL) in the central airhole of a dual core photonic crystal fiber (PCF). The temperature dependent propagation characteristics of modes in the dual core PCF are analyzed numerically.
A cascaded string of six intrinsic Fabry-Perot Interferometer sensors was fabricated inside a silica fiber using ultrafast laser direct writing, then interrogated by fast white-light interferometer demodulation. Temperature sensitivity between 4.4-13.4nm/0C for up to 8000C at a spatial resolution of 1-cm was acquired.
Dispersion tailoring of asymmetric vertical-dual slot waveguides in Silicon-on-Insulator is performed. The asymmetry introduced in widths and position of dual slots are utilized to engineer the dispersion characteristics of the photonic waveguide.
An optimal resource allocation scheme is proposed for cooperative hybrid FSO/mmW 5G fronthaul network to optimize network reliability, average transmitted power and average BER. The numerical results reveal achieving significant improvements in network performance by implementing the proposed scheme, especially at severe weather conditions.
Thermal crosstalk and fabrication variations are detrimental to accurate control of integrated photonic systems. We build a calibration-based control algorithm accounting for these factors in a dual Mach-Zehnder Interferometer (MZI) structure, and experimentally demonstrate automated control of optical transmission with only 3% error.
In this paper, we propose methods to reduce modulation depth requirements of optical modulators in an optical full adder while still maintain the accuracy by optimizing parameters using algorithms. Results show that it is capable of reducing power consumption effectively.
Starting from the well-known transmission matrix of four port ring resonators we develop a simplified generalized scattering matrix of their phase response for their use in linear coherent optical networks.
1310nm Fabry-Perot QW lasers with ultra-short cavity are fabricated. The shortest cavity length is 25mm, and the laser has mW-class output with low threshold currents. At room temperature, an opened eye diagram with 28Gb/s transmission rate and 25Gb/s eye patterns from 15oC to 65oC are demonstrated.
An oxide aperture strained quantum well VCSEL model was built based on measured results. The indium composition of MQW was changed to maximize the frequency response. The simulation result shows that the bandwidth can be improved and reach 30.88GHz.
When operated in the coherently coupled regime, microcavity laser diode arrays have an electrical signature in their differential series resistance. The mechanism of this effect is explained using a complex coupling coefficient in coupled mode rate equation theory.
We present preliminary characterization results of the first InAs/InAlGaAs/InP 1.3μm quantum dots (QDs) laser directly grown on (001) silicon. A threshold current density of 1.05 kA/cm2 under pulsed current injection has been obtained. A 50 ns width optical pulse was observed under gain-switching measurement.
We present a thin silicon nitride waveguide array that achieves a broadband near-zero dispersion profile at near-infrared (1350 - 1800 nm). Multiple mode couplings are introduced at four different wavelengths by coupling different orders of modes.
We investigate the interactions of solitons in a dual-core system where one core is uniform and has cubic-quintic nonlinearity and the other is linear with a Bragg grating. The effects of system parameters on the outcomes of the interactions are discussed.
The existence and stability of moving gap solitons in a coupled fiber Bragg gratings with dispersive reflectivity in a cubic-quintic nonlinear medium are investigated. The effect of dispersive reflectivity on the stability of solitons is analyzed.
We present a novel digital design process to synthesize unequal cavity lengths of multi-etalon structures in order to enhance their FSR. As an example, we synthesize a multicavity system with the stop-band rejection of -40dB and 15 times FSR enhancement from a given configuration.
We present dynamic optical strain measurements on a metallic cylinder asymmetrically loaded by explosives bands using 24 fiber Bragg gratings distributed along three fibers. The 100 MHz dispersive spectrometer reveals resonances without any electromagnetic perturbations compared to slower electrical strain gauges.
We investigate the oxidization confinement method applied in the active layer of the ridge waveguide Quantum Cascade Laser (QCL). Threshold current of the ridge oxidized QCL is lower than the conventional one, suggesting that the current is constricted by the oxidized layers.
We experimentally demonstrate that the relative intensity noise of a quantum cascade laser is insensitive to optical feedback. The feedback induced noise variation is less than 2.5 dB up to a feedback ratio of 31%. Rate equation analysis agrees well with the experimental observation.
We theoretically demonstrate that strong optical feedback can reduce the frequency noise of quantum cascade lasers by two orders of magnitude, which is almost independent on the feedback phase. In addition, the spectral linewidth of the laser with optical feedback is analytically derived.