Noiseless amplification in cavity-based optical systems with an internal two-photon process. II. Self-frequency-doubling laser and second-harmonic generation, self-down-converting laser

We consider a cavity containing both a ?(2)-nonlinear material and a laser two-level medium for the cases of self-frequency-doubling and self-down-converting configurations. For both situations, the squeezing properties of the two fields are analysed in detail, while special attention is devoted to the problem of 'noiseless amplification' of a small monochromatic signal injected in the lower frequency mode.