GENERATION OF BROAD-BAND SQUEEZED STATES PUMPED BY CW MODE-LOCKED PULSES

Broadband high level squeezing was clearly observed from 100 kHz to 80 MHz using crystals Ba2NaNb5O15 of 5 mm length, MgO: LiNbO3 Of 19 mm length and KNbO3 of 5.8 mm length. Maximum noise reductions detected on a spectrum analyzer were -1.2 dB (-24%), -1.25 dB (-25%), and -1.8 dB (-34%) for the three crystals, respectively. The maximum squeezing is limited mostly by "optical index damage" of the parametric crystals. A detailed analysis of the beam parameters traced along the pump beam, squeezed vacuum, etc. is given. A detailed discussion on the evaluation of the initial squeezed level is given. A preliminary experiment with compressed laser pulses to avoid the optical damage is also described.