Testing a lidar imager
Underwater lidars

Given the current state of laser technology, we felt that only one scheme could reconcile range and resolution in a feasibility study: scanning the area to be imaged with a pulsed laser beam and using a photomultiplier-type point detector. The advantage of scanning is that the full power of the laser (which on average remains low) is used to obtain information about a pixel in the image, and that the number of pixels in the image can be modulated according to the scanning parameters.

The Neodymium YAG laser, pulsed and doubled, emitting green light at 532 nm, is currently a good compromise for this type of implementation.

Imaging experiments were carried out in a seawater tank, using a device implementing the previously proposed design (scanning and emission of short, powerful pulses).