Waveguide Grating Router PhaseTrimming for a Fine ResolutionPhotonic Spectral Processor

Thesis Type:

MSc thesis


Spectrally dispersed light from a fine resolution waveguide grating router (WGR) of 25 GHz free spectral range (FSR) that radiates to free-space is spatially filtered at ~1 GHz resolution using a liquid crystal on Silicon (LCoS) spatial light modulator (SLM). Fabrication imperfections leading to phase errors on the 32 waveguide arms of the WGR are measured by the pair-wise far-field interference of adjacent waveguide pairs. The phase errors are then corrected using a UV pulsed laser to inscribe permanent optical path changes to the waveguides. WGR phase errors are permanently trimmed waveguide-by-waveguide with an excimer laser by inducing stress in the glass cladding above the waveguide for coarse setting and using the photosensitivity effect for fine setting. The WGR was then mated with an LCoS SLM located at the Fourier plane to form a photonic spectral processor (PSP), for arbitrary spectral amplitude and phase manipulations.

Publisher's Version

Last updated on 10/25/2016