Effects of tilt and offset of signal field on heterodyne efficiency

The effects of tilt and offset on the heterodyne efficiency are discussed for optical fields with Gaussian field distributions. An aperture is used in the input plane of the system to decrease the background noise which is incident on the signal. The numerical results show that in optimum conditions of the system and beam fields, the tilt must be less than ~10(-4) deg and the offset about one-fifth of the input aperture to obtain more than 60% of the ideal values of the efficiency.