Fully Integrated FMCW LiDAR Optical Engine on a Single Silicon Chip

Abstract

We present the demonstration of two novel chip-scale FMCW LiDAR optical engines in which all photonic components, including the laser sources, were integrated on single silicon chips. Using the first LiDAR chip design, with an integrated distributed Bragg reflector laser and grating couplers as input/output ports for the receive/transmit light, we demonstrated a maximum range of 28 m limited by transmit light output power of 2 mW. We further demonstrated a maximum range of 75 m using a second LiDAR chip architecture having an on-chip sampled grating distributed Bragg reflector master laser with integrated power amplifier in which the local oscillator light was obtained from the laser back facet. This maximum range can be further increased by improving the laser linewidth. The measured range dependence of the FMCW signal level for both LiDAR chips agreed well with theory. The chip-scale FMCW LiDAR optical engines can be used in conjunction with a variety of off-chip two dimensional beam scanners to realize a chip-scale scanning LiDAR solution. To the best of our knowledge, this is the first published demonstration of fully integrated FMCW LiDAR optical engines on a single silicon chip.

Focal plane array with small-scale grating antenna receiving array for LiDAR

“…Eq. ( 2) represents the fundamental radar equation 14 , where P TX and P RX denote the transmitter's outgoing power and the power detected by the receiver, respectively. Additionally, ρ signifies the target's reflectivity, A indicates the receiver's effective aperture, and R represents the distance to the target.…”

128-channel optical phased array with large field of view and low main-lobe attenuation

“…Several research teams have conducted related chip detection studies and made exciting progress [1][2][3][4]. According to the lidar ranging equation [5], the relationship between emission optical power and detectable distance is represented by P1/ P0∝1/D2, where P1 represents the power of the received reflected light, P0 is the optical power of the emitted light (main-lobe), and D is the detection distance. The MIT team achieved detection of a 10% reflective object at a distance of 35 m using 50 mW of main lobe optical power [3].…”

FMCW LiDAR based on integrated coherent receiver chip

“…220nm and 3 microns SOI waveguide platforms are the main technologies used in silicon photonics, and various components of the LiDAR system on the chip based on the 220nm SOI platform have been presented [6][7][8][9] due to its open resource and easy access. They have already demonstrated the capabilities of detecting moving targets and solid-state beam control, among others.…”