Optical Science and Engineering ETDs

Publication Date

Summer 8-1-2022

Abstract

We demonstrate two applications based on grating coupled phase matching to a slab waveguide: lab-on-a-chip spectrometer using a transversely chirped grating and indoor lidar plenoptic sensor array for Time of flight (ToF) position mapping system. In the first application, a chirped grating waveguide coupler serves as a spatially dependent narrow-band filter. The transversely-chirped-input grating is fabricated on a SiO2-Si3N4-SiO2 waveguide atop a Si substrate by interferometric lithography. Light with wavelength from 400- nm to 700 nm couples into Si3N4 waveguide through transversely chirped grating incident at a 33.5⁰ angle and is detected by a 2048-element linear CMOS detector array. A wavelength dependent resolution of2. The goal of second application is to fabricate a time-of-flight sensor array based on grating-coupled waveguide looking in many different directions and covering a large azimuth/altitude footprint by standard microelectronic manufacturing. Light emitted by 940 nm VCSEL is scattered from objects and grating coupled into a slab waveguide. Light is coupled into one or more grating detectors and rejected by others due to phase mismatching with different grating periods and orientations. The acceptance angle of scattered light is determined by the waveguide properties and grating period/orientation of the detector. As the grating coupler works as narrow-band filter, the plenoptic sensor displayed a good immunity to background light sources. Devices were fabricated in a commercial foundry process, making this amenable to low-cost, large-scale manufacturing.

Degree Name

Optical Science and Engineering

Level of Degree

Doctoral

Department Name

Optical Science and Engineering

First Committee Member (Chair)

Steven R. J. Brueck

Second Committee Member

Payman Zarkesh-Ha

Third Committee Member

Tito Busani

Fourth Committee Member

Tara Drake

Keywords

integrated grating coupler, chirped grating, indoor lidar

Sponsors

ARPA-E

Document Type

Dissertation

Language

English

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