Optimal local oscillator field for a monostatic coherent laser radar with a circular aperture.

The optimal local oscillator (LO) field for maximum coherent laser radar power (or signal-to-noise ratio) of a monostatic coherent laser radar with a circular aperture is calculated for various radially symmetric transmitter laser fields (Gaussian and unstable resonator), assuming a diffuse or aerosol target. The optimal field is essentially identical with previous designs based on a Gaussian field for the LO. The secondary optics that will produce these optimal LO fields is described.