Fiber Optic Valley

In this paper, proton implantation with different combinations of MeV energies and doses from 2×109 to 1×1011 cm-2 is used to create defects in the drift region of 10 kV 4H-SiC PiN diodes to obtain a localized drop in the SRH lifetime. On-state and reverse recovery behaviors are measured to observe how MeV proton implantation influences these devices and values of reverse recovery charge Qrr are extracted. These measurements are carried out under different temperatures, showing that the reverse recovery behavior is sensitive to temperature due to the activation of incompletely ionized p-type acceptors. The results also show that increasing proton implantation energies and fluencies can have a strong effect on diodes and cause lower Qrr and switching losses, but also higher on-state voltage drop and forward conduction losses. The trade-off between static and dynamic performance is evaluated using Qrr and forward voltage drop. Higher fluencies, or energies, help to improve the turn-off performance, but at a cost of the static performance.

This work describes the use of FBGs inscribed in optical fiber with electrodes for voltage sensing. The results show a quadratic voltage dependence. The device can be explored for a multipoint, single-ended voltage sensing device.

We demonstrate a tunable narrow-linewidth laser based on a semiconductor optical amplifier and a linearly chirped FBG. High tuning resolution and small power variation over 40 nm tuning range were achieved by optimizing the drive current. © 2019 The Author(s)

Optofluidics is exploited in an all-fiber component to detect and identify through fluorescence particles flowing at high rate and inertially focused in a capillary. The system represents a first step towards an in-fiber flow cytometer.

The integration of a microspherical whispering gallery mode (WGM) resonator inside a microstructured optical fiber taper is demonstrated. Preliminary WGM spectra of this in-fiber resonator in transmission mode are presented and discussed.

An all-fiber dye laser is demonstrated. The dye solution is kept under flow, allowing for high repetition rate pumping. Threshold average pump power of 2.15 mW and conversion slope efficiency of ~8.5% are achieved.

We present a novel all-vapor phase fabrication method for producing Yb-doped fibers by atomic layer deposition (ALD) in combination with the well-established modified chemical vapor deposition (MCVD) technique. An MCVD soot-preform with a porous layer of SiO2 is coated with layers of Yb2O3 and Al2O3 prior to sintering, using a gas-phase ALD method. An Yb-doped fiber fabricated by this technique shows low background attenuation, uniform longitudinal Yb-doping profile, and good laser characteristics with a slope efficiency of 80%.

Fibers with internal electrodes are driven electrically. They allow for the control of polarization, wavelength tuning, nanosecond light gating, Q-switching and mode-locking of lasers. These are some of the applications discussed in this paper.

Paper 82580P