Critical petermann K factor for intensity noise squeezing
We investigate the impact of the Petermann-excess-noise factor K>/=1 on the possibility of intensity noise squeezing of laser light below the standard quantum limit. Using an N-mode model, we show that squeezing is limited to a floor level of 2(K-1) times the shot noise limit. Thus, even a modest Petermann factor significantly impedes squeezing, which becomes impossible when K>/=1.5. This appears as a serious limitation for obtaining sub-shot-noise light from practical semiconductor lasers. We present experimental evidence for our theory.
van Der Lee AM
Huygens Laboratory, Leiden University, P.O. Box 9504, Leiden, The Netherlands.
van Druten NJ
van Exter MP
Woerdman
JP
Poizat
JP
Grangier
P