An optical parametric amplifier (OPA) has been demonstrated in bulk, periodically poled lithium niobate and is shown to operate with a noise figure well below the classical limit. In contrast to conventional OPA’s, this device uses quasi-phase matching to provide the coupling between the pump and the signal. Comparison of the measured performance with that of a theoretical model reveals that the main intrinsic contribution to the output noise is due to spatial and temporal mode mixing, which arises as a consequence of tight focusing of the incident beams. Factors that affect the performance of this amplifier are identified theoretically and their relative importance investigated for both amplification and squeezing.
© 1996 Optical Society of America
D. J. Lovering, J. A. Levenson, P. Vidakovic, J. Webjörn, and P. St. J. Russell, "Noiseless optical amplification in quasi-phase-matched bulk lithium niobate," Opt. Lett. 21, 1439-1441 (1996)