Laser optical feedback imaging. A new way for lasers to see the world

Summary form only. Optical interferometry is a powerful tool for the measurement of distances, velocities and vibrations with a high degree of accuracy. We have constructed an interferometry arrangement using a class B laser source, to obtain a highly sensitive technique for imaging target parameters. This Laser Optical Feedback Imaging technique (LOFI) takes advantage of the class B laser´s high sensitivity to optical feedback. In standard interferometry, there are two beams, a reference and a probe which are recombined after having followed different optical paths. We demonstrate that for weak feedback, a system composed of a mini laser (microchip or diode laser) and an optical frequency shifter is similar to a heterodyne interferometer without the need of a reference beams. In LOFI, the source is a small class B single longitudinal and transverse mode laser The laser beam is frequency shifted by an acousto-optic deflector and is focused within a solid angle on the target under investigation.