Experimental results are reported for amplitude-squeezed states generated from two kinds of 1550-nm distributed-feedback semiconductor laser at room temperature. Both lasers exhibit excess noise under free-running conditions, but the origin of this noise is different for the two lasers. For one of the lasers the excess noise is reduced by enhancement of the side-mode–suppression ratio. For the other the excess noise that degrades the squeezing is reduced by weak dispersive optical feedback produced by a grating detuned from the maximum of its first-order reflection. Thus the grating is used to convert phase noise into intensity noise.
© 1999 Optical Society of America
(140.3490) Lasers and laser optics : Lasers, distributed-feedback
(140.5960) Lasers and laser optics : Semiconductor lasers
(270.2500) Quantum optics : Fluctuations, relaxations, and noise
(270.6570) Quantum optics : Squeezed states
F. Jérémie, C. Chabran, and P. Gallion, "Room-temperature generation of amplitude-squeezed light from 1550-nm distributed-feedback semiconductor lasers," J. Opt. Soc. Am. B 16, 460-464 (1999)