5. Other optical processing functions

5.1 Optical microwave mixing

Current work focuses on the development of microwave optoelectronic processors for low-frequency conversion, and in particular on the rejection of the image signal at the mixer output and on improving conversion efficiency.

The mixer structure is shown in figure 31 . A laser source supplies a continuous wave with linear polarization aligned along the slow axis of a dual MZM modulator with phase modulator. The two outputs of the MZM modulators are of orthogonal polarization, and are combined in a PBC polarization combiner. The modulators are biased at the minimum transmission point to suppress the optical carrier. After...