Tool Used: OptSim
This application note illustrates a basic setup to achieve a swept frequency light source commonly used for LiDAR applications in automotive cruise control (ACC) and automotive collision avoidance systems (ACAS) [1-2].
Since chirped frequency scanning requires lower power and can transmit and receive at the same time, it is more popular than pulsed scanning in automotive LiDAR systems. However, compared to pulsed radar, chirped frequency scanning is complex to implement.
Since the chirp is precisely linear, a scatterer with round-trip delay τ (and a corresponding distance cτ/2 from the source, c is speed of light) results in constant frequency difference ξt between the launched and reflected waves.
Such a scanning would require an optical frequency modulated continuous-wave (FMCW) source [2]. The purpose of this application is to show how to create such a source in OptSim.
The topology layout is shown in Figure 1 below.