Frequency Stabilization of AlGaAs Semiconductor Laser to the Absorption Line of Water Vapor

Abstract
The absorption spectrum of water vapor in the (2, 1, 1) vibration-rotation band has been observed by using an AlGaAs semiconductor laser around 0.82 µm. The laser frequency was stabilized to one of the absorption lines by controlling the injection current. A frequency stability of 1.9×10-9≧σ≧1.1×10-11 was obtained for 10 ms≦τ≦500 s.