Fig. 1
From: Pockels laser directly driving ultrafast optical metrology
Concept of integrated Pockels laser for optical metrology applications. a Outlook of Pockels lasers and their potential applications. Bottom: Schematic of the integrated eDBR-based Pockels laser. b Schematic of laser frequency stabilization via PDH locking. Top: Conventional PDH locking configuration. Bottom: Simplified PDH locking using Pockels laser. AOM acousto-optic modulator, PC polarization controller, AMP optical amplifier, PD photodetector. c Schematic of distance metrology and velocimetry measurements by FMCW LiDAR. Top: normal detection regime for FMCW LiDAR. Bottom: false detection caused by large velocity and/or short distance. d Optical microscopic images of the integrated eDBR-based Pockels laser. e Schematic of the cross-section of the DBR section. f Scanning electron microscopic images of the DBR section. g Left and middle: Photo and its zoomed-in view of the laser device under testing. Right: Photo of the full TFLN external cavity PIC chip (compared with a penny coin shown in the background). h Simulated reflection spectrum (left two figures) and coupling coefficient κ (right figure) of the DBR at varied etch depth and cladding thickness. The DBR grating in simulation has a period of 400 nm (corresponding to an optical frequency centered around 192.8 THz), with a total number of 10,000 periods
