Basic module for an integrated optical phase difference measurement and correction system

Abstract

A basic module for an integrated optical phase difference measurement and correction system was developed and fabricated in the GaAs-AlGaAs material system. The implemented device made it possible to measure the relative phase difference between two waveguides using a small fraction of the power (<10%) for diagnostic purposes. This proof-of-concept device incorporated waveguides, waveguide couplers and Y-junctions, phase modulators, and photodetectors on the same substrate. This thesis describes the design, fabrication and operation of the implemented device. Waveguide phase modulators with Vx=5.0V for =-0.865gm were fabricated. Selective Be ion implantation and rapid thermal annealing was used to form the p+-n--n + modulator structure. The phase was modulated via the linear electrooptic effect in the reverse-biased p+-n--n + structure. A Y-junction interferometer was used to obtain the relative phase difference between the two waveguides. Integrated MSM photodetectors, 17x69gm in size, with TIR mirror coupling were used for signal detection. Both, the interferometer and detector were fabricated and operated between two, 30gtm separated waveguides. A phase dither detection system made it possible to determine the relative phase between two waveguides largely independent of the power ratio between the individual guides.

InP-based PIC for an optical phased array antenna at 1.06 μm

“…We have investigated the feasibility of the InGaAsP-InP technology for the realization of a PIC for phase control of optical transmission at 1.06 m. This PIC is to be integrated in an optical phased telescope array system [1]. A similar PIC based on AlGaAs-GaAs technology has already been reported earlier [2]. In this letter, InGaAsP-InP is preferred over the AlGaAs-GaAs material system because of the better resistance to cosmic radiation of InP and the superior efficiency of InP-based detectors (which, in a next step, will be integrated on the PIC) at the 1.06-m wavelength.…”