Optical frequency comb based parallel fm lidar

Abstract

In a LIDAR device () a laser light source () generates first laser light having a first laser frequency which is frequency modulated with a first frequency modulation. A non-linear optical element () receives the first laser light and generates therefrom second laser light having a comb-like frequency spectrum with a plurality of second laser frequencies which are each frequency modulated with a second frequency modulation defined by the first frequency modulation. A frequency excursion of the second frequency modulation is smaller than a spacing of the second laser frequencies. A diffractive element () spatially separates the second laser light according to the second laser frequencies and directs the spatially separated second laser light towards a ranging region (), with each of the second laser frequencies being directed towards a corresponding spatially distinct target position in the ranging region (). A detector () receives reflections of the second laser light from the ranging region () and measures, by simultaneously detecting a frequency modulation of the reflections for each of the second laser frequencies, a distance and/or a velocity at the target position corresponding to the second laser frequency.