On-Chip Planar Lens Architectures for Optical Beam Steering

Free-space optical beam steering is an important technological capability because of its applications in optical communication links and sensing such as light detection and ranging (lidar). Over the past decade, there has been significant efforts to develop a beam steering architecture that can lead...

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Bibliographic Details
Main Author: López, Josué Jacob
Other Authors: Soljačić, Marin
Format: Thesis
Published: Massachusetts Institute of Technology 2022
Online Access:https://hdl.handle.net/1721.1/144588
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author López, Josué Jacob
author2 Soljačić, Marin
author_facet Soljačić, Marin
López, Josué Jacob
author_sort López, Josué Jacob
collection MIT
description Free-space optical beam steering is an important technological capability because of its applications in optical communication links and sensing such as light detection and ranging (lidar). Over the past decade, there has been significant efforts to develop a beam steering architecture that can lead to solid-state lidar with lower size, weight, power consumption, and cost (SWaP-C) while still meeting a high level of sensing performance and reliability. Herein, is the experimental demonstration of two novel planar lens-based architectures for optical beam steering in two dimensions. The first experimental demonstration is an aplanatic lens designed via the paraxial ray approximation and ray tracing. The second experimental demonstration is a Luneburg lens that is designed with a gradient in the refractive index along the radius of the lens. This second system uses a circularly symmetric grating to emit the optical beam over a wide field of view. Both planar lens architectures leverage a near-infrared tunable laser, a Mach-Zehnder interferometer switch tree, the lens that collimates and steers an optical mode in-the-plane of the chip, and a wavelength dependent grating for out-of-plane coupling. Various grating designs are presented towards the improvement of the effective aperture length and optical power emitted from the grating including double-layer grating designs and apodization schemes for the grating fill-fraction. Both devices are fabricated using a wafer-scale fabrication process and pave the way for two-dimensional optical beam steering with low electronic complexity and a large field of view. Lastly, remaining architecture challenges for a high performance lidar-on-a-chip system are discussed.
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spelling mit-1721.1/1445882022-08-30T03:11:33Z On-Chip Planar Lens Architectures for Optical Beam Steering López, Josué Jacob Soljačić, Marin Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Free-space optical beam steering is an important technological capability because of its applications in optical communication links and sensing such as light detection and ranging (lidar). Over the past decade, there has been significant efforts to develop a beam steering architecture that can lead to solid-state lidar with lower size, weight, power consumption, and cost (SWaP-C) while still meeting a high level of sensing performance and reliability. Herein, is the experimental demonstration of two novel planar lens-based architectures for optical beam steering in two dimensions. The first experimental demonstration is an aplanatic lens designed via the paraxial ray approximation and ray tracing. The second experimental demonstration is a Luneburg lens that is designed with a gradient in the refractive index along the radius of the lens. This second system uses a circularly symmetric grating to emit the optical beam over a wide field of view. Both planar lens architectures leverage a near-infrared tunable laser, a Mach-Zehnder interferometer switch tree, the lens that collimates and steers an optical mode in-the-plane of the chip, and a wavelength dependent grating for out-of-plane coupling. Various grating designs are presented towards the improvement of the effective aperture length and optical power emitted from the grating including double-layer grating designs and apodization schemes for the grating fill-fraction. Both devices are fabricated using a wafer-scale fabrication process and pave the way for two-dimensional optical beam steering with low electronic complexity and a large field of view. Lastly, remaining architecture challenges for a high performance lidar-on-a-chip system are discussed. Ph.D. 2022-08-29T15:57:39Z 2022-08-29T15:57:39Z 2022-05 2022-06-21T19:15:21.121Z Thesis https://hdl.handle.net/1721.1/144588 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle López, Josué Jacob
On-Chip Planar Lens Architectures for Optical Beam Steering
title On-Chip Planar Lens Architectures for Optical Beam Steering
title_full On-Chip Planar Lens Architectures for Optical Beam Steering
title_fullStr On-Chip Planar Lens Architectures for Optical Beam Steering
title_full_unstemmed On-Chip Planar Lens Architectures for Optical Beam Steering
title_short On-Chip Planar Lens Architectures for Optical Beam Steering
title_sort on chip planar lens architectures for optical beam steering
url https://hdl.handle.net/1721.1/144588
work_keys_str_mv AT lopezjosuejacob onchipplanarlensarchitecturesforopticalbeamsteering