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HL: Fachverband Halbleiterphysik
HL 88: Lasers
HL 88.6: Talk
Friday, March 18, 2011, 11:30–11:45, POT 151
Laser Diode Self-Mixing Velocimetry of Solid and Liquid Targets — •Thomas Gläßer1, Wolfgang Elsäßer1, and James O'Gorman2 — 1Institut für Angewandte Physik, Technische Universität Darmstadt, Schloßgartenstraße 7, 64289 Darmstadt — 2previously with Eblana Photonics, Dublin (Ireland)
The laser diode self-mixing (or optical feedback) interferometry technique is a contactless measurement technique based on a very simple configuration. The setup consists only of a laser diode (LD), the focusing optics and the target to be probed. The laser beam is scattered by the target and partly back reflected into the laser cavity. This leads to a interferometric carrier and power modulation of the LD containing information about the velocity of the target. For signal detection a monitor photodiode included in the LD package could be used.
Compared to the widely established laser doppler velocimetry (LDV), which is based on Mach Zehnder or Michelson interferometers, the self-mixing approach provides advantages in its setup size and wight and allows much easier adjustment at very low cost.
We present velocity measurements on different flowing liquids using near infrared discrete mode LDs at 1300 nm and 1550 nm.