The main hindrance to optical imaging at elevated depths is the scattering of light exhibited by biological tissues. Consequently, various wavefront shaping techniques have been developed in order to achieve focusing in scattering media. In our scattering compensation experiments, the spatial light modulator is replaced by a novel integrated photonics-based wavefront shaper. We work on focusing through a static scatterer using near-infrared light. The photonic integrated circuit (PIC) used in this research consists of a 1D array of optical emitters with independently controlled phases. This PIC-based wavefront shaper was fabricated on a CMOS-compatible platform offering the prospect of large-scale fabrication.
This paper presents the optimization of novel material stacks and functions targeting solid-state phase-front shaping in NIR for sensing (LiDAR, imaging, spectroscopy).
We report on direct time-of-flight and frequency modulated continuous wave detection and ranging (LiDAR) implementing 2D scanners with on-chip optical calibration using Si-based photon-assisted tunneling diodes at 1.55µm. We finally introduce developments towards multi-beam scanning with low divergence, low power phase shifting and advanced light source integration through PIC hybridization with gain media, all key developments for LiDAR and alternative emerging applications, e.g. line-of-sight optical telecom, deep tissue imaging and gas sensing.
Correcting phase errors is key to building low cost, high performance integrated optical phased arrays for mass-market applications such as automotive lidar. In this work, we present a phase interrogator component for optical phased arrays which enables the phase error to be measured immediately before the output array of optical emitters. A 32-element silicon/silicon nitride optical phased array is realized in a dual layer photonics stack to verify the component performance. Silicon enables high density integration of photonic components and the phase interrogator has a compact design which fits between waveguides with a separation of 2.5 μm. The phase interrogators enable correction of the beam without any measurement or evaluation of the far-field.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.