Optimization Of Coupling Efficiency Research Articles

Research on Optical Fiber Ring Resonator Q Value and Coupling Efficiency Optimization.

The coupling efficiency of the fiber ring resonator has an important influence on the scale factor of the resonant fiber gyroscope. In order to improve the scale factor of the gyroscope, the coupling efficiency of the fiber ring resonator and its influential factors on the scale factor of the gyroscope are analyzed and tested. The results show that the coupling efficiency is affected by both the splitting ratio of the coupler and the loss in the cavity. When the coupling efficiency approaches 0.75 at the under-coupling state, the scaling factor of the gyroscope is the highest. This provides a theoretical reference and an experimental basis for the enhancement of the scaling factor of the resonant fiber gyroscope with the fiber ring resonator as the sensitive unit, providing options for multiple applications such as sea, land, sky and space.

Optimization of Coupling Efficiency in Butterfly Optical Communication Laser Based on Chaotic Adaptive Seeker Optimization Algorithm.

A chaotic adaptive seeker optimization algorithm (CASOA) is proposed in this study to improve the coupling efficiency and accuracy of a butterfly optical communication laser. It primarily relies on chaotic disturbance to improve seeker search performance. The chaotic disturbance enables the algorithm to jump out from local extremes. Furthermore, chaos is associated with a novel strategy for optimizing search paths with a small population. A simulation and experiment are conducted to demonstrate that the CASOA with a few seekers has an excellent search success rate with few iterations in the coupling alignment. These results indicate that the proposed CASOA can reliably improve the coupling accuracy and efficiency of laser diodes and single-mode fibers.

A Semi-Automated System for Wafer-Scale Optical Waveguide Characterization.

Integrated photonic waveguide systems are used in biomedical sensing and require robust, high-throughput methods of characterization. Here, we demonstrate a semi-automated robotic system to characterize waveguides at the wafer-scale with minimal human intervention based on imaging the outscattered light to measure the propagation loss. We demonstrate automated input coupling efficiency optimization using closed-loop control of the input fiber position. The automated characterization system collects and combines multiple images of the waveguide to measure the propagation loss. This system allows high-throughput characterization of integrated photonic waveguides and lays the foundation for a fully automated and high throughput system to characterize photonic waveguides at the wafer scale.Clinical Relevance- This method enables high precision, high throughput characterization of optoelectrical neural probes to maximize the yield of surgical implantation and electrophysiology recording.

Coupling Efficiency Optimization for the Optical Fiber Lens with Oval-Shaped Endfaces by Applying Uniform Design and Kriging Interpolation

Coupling Efficiency Optimization for the Optical Fiber Lens with Oval-Shaped Endfaces by Applying Uniform Design and Kriging Interpolation

An all-fiber mode converter assisted by coiled-fiber long-period grating

An all-fiber mode converter assisted by coiled-fiber long-period grating (CFLPG), which is formed by periodically coiling one thin tapered single-mode fiber (SMF) onto one thick straight tapered few-mode fiber (FMF), is experimentally demonstrated. Owing to the strong periodic modulation of the coiled tapered SMF to evanescent field of the straight tapered FMF, specific higher-order modes in the FMF can be successfully excited from the fundamental mode of the SMF. Moreover, coupling efficiency from fundamental mode of the SMF to specific higher-order mode of the FMF can be optimized by adjusting the number of the coiling period, which is beneficial for the design and fabrication of mode converter. This proposed structure can be extended to even higher-order mode conversion, and has flexibility in coupling efficiency optimization and compatibility with current optical fiber communication systems.

Tunability and Optimization of Coupling Efficiency in Tamm Plasmon Modes

A Tamm plasmon polariton is a plasmonic resonance excited at the boundary between a photonic crystal and a metal. In this paper, a novel approach based on admittance loci is proposed to demonstrate the relation between thin-film structures and the corresponding Tamm plasmon modes. The tunability of the resonance wavelength and optimization of coupling efficiency are demonstrated. In addition, by using different metals to couple Tamm plasmon modes in the visible spectrum, silver has 4.7 times larger Q-factor than gold and 84 times larger than aluminum at 700 nm. The near-field enhancement of silver Tamm plasmon modes could be up to eight times larger than incident EM waves.

Compact modulated and tunable microdisk laser using vertical coupling and a feedback loop

A study of vertical coupling conditions between microdisk based resonators and waveguides is presented using an analytical model. The coupling efficiency optimization is investigated and compared to 3D FDTD computations. We also demonstrate that coupling losses can be exploited to favor high quality factor modes in circular resonators. In addition, we propose to modify the shape of the coupled waveguide to enhance mode selectivity and obtain a very compact structure with mode hoping capacities. Lower thresholds and modulation are also expected.

Investigation of dilute SF6 discharges for application to SiC reactive ion etching

Impedance matching and power coupling efficiency optimization of SF6 gas discharges diluted with Ar and He have been compared in relation to reactive ion etch rates and etched feature anisotropy of hexagonal (6H) silicon carbide (SiC). In contrast to the measured radio frequency (rf) power coupling efficiency, He diluted mixtures resulted in greater etch rates by up to 50%, with superior anisotropy and surface morphology than comparable Ar:SF6 mixtures. The superior etched surface finish for the He diluted mixtures possibly arises from the less severe sputtering damage of SiC for He+ and SFX+, compared to Ar+ with the same energy. Etch rates over 3300 Å/min have been achieved with excellent surface morphologies and anisotropy. These results conflict with the notion that Ar+ ions are expected to enhance the ion assisted etch mechanism in technical gas mixtures. We observed superior, SiC etch performance for He:SF6 mixtures, compared to Ar:SF6, over the entire 10%–90% fractional ratios investigated. This result appears to be due to differing bulk discharge chemistries which control the flux of radicals and ions to the substrate, resulting in optimal surface polymerization conditions. This suggestion is based on our estimated bulk E/n values, known partial ionization cross sections, production rate coefficients for SF3+ and SF5+, and higher electron energy distributions for He dilution. In addition, we provide further evidence for the generic nature of utilizing the complex electrical characteristics of the rf discharge to optimize plasma etch conditions. On the other hand, we have demonstrated that understanding the details of gas phase kinetics is also necessary to fully exploit the power coupling optimization scheme for rf discharges, which are specific to the gas mixtures being utilized.