Laser excess noise reduction in optical phase-shift measurements.
We describe an optical detection scheme that reduces laser excess noise in measurements of small optical phase shifts. The scheme improves the sensitivity of the balanced differential detection. Analysis of the scheme and comparison with the conventional detection are presented. The scheme is applied in electro-optic probing of electrical signals in integrated circuits, where the excess laser noise is reduced by approximately 20 dB.
Lucent Technologies, Bell Laboratories, 600 Mountain Avenue, Murray Hill, New Jersey 07974, USA. olegm@lucent.com
Oleg
O
Mitrofanov