Keywords:Silicon photonics, Hybrid laser, Bragg grating
LiDAR (Light Detection and Ranging) is extending its role in many applications such as autonomous cars and drones. We are developing a one-chip FMCW LiDAR system on Silicon photonics platform using slow-light grating couplers and hybrid lasers . In this system, a tunable 1.55-µm DFB laser with <1-nm tuning range, ~100-kHz scanning speed, while maintaining high power (>100 mW) and narrow linewidth (~few hundred kHz), is required. Distributed feedback via sidewall Bragg grating structure patterned on the sidewalls of the Si waveguide is concerned in this study rather than the conventional top-etched one so as to reduce process complexity and avoid possible thermal issues. In this report, 2-µm-width Si waveguide sidewall Bragg grating was fabricated to check the deviation between design and measurement in terms of the mode coupling coefficient (κ) and scattering loss (αs) as a step towards such DFB lasers.