Multispectral LiDAR transceiver

A scanning device for laser detection and ranging (LiDAR), the scanning device comprising, arranged in optical free space:

• an optical input for receiving a pulsed broadband laser beam, the pulsed broadband laser beam having a linear polarization;
• a separating unit configured for transmitting the pulsed broadband laser beam along a scanning optical path while changing the linear polarization into a circular polarization;
• a wavelength selection unit configured for:
• receiving the pulsed broadband laser beam from the separating unit,
• filtering the pulsed broadband laser beam in order to get a filtered laser beam having a current wavelength that can be selected among a plurality of selectable wavelengths, and deflecting the filtered laser beam on a scanning unit along the scanning optical path to result in a deflected filtered laser beam,
• the scanning unit being configured:
• to steer the deflected filtered laser beam along a plurality of current local directions inside a predefined solid angle,
• to receive reflections of the filtered laser beam, the reflections coming back from surroundings, the reflections having an orthogonal circular polarization compared to the circular polarization of the pulsed broadband laser beam, and
• to transmit back the received reflections to the separating unit through the wavelength selection unit along a detection optical path, wherein the detection optical path and the scanning optical path have a same light path through the wavelength selection unit and the scanning unit, but opposite direction of light propagation,
• wherein the separating unit is further configured for deviating the reflections on a broadband detector while changing the orthogonal circular polarization into an orthogonal linear polarization compared to the linear polarization of the pulsed broadband laser beam,
• the broadband detector being configured
• to receive deviated reflections deviated by the separating unit, and
• to detect a time-of-flight and an optical power of the deviated reflections.