High-Efficiency KU-Band SSB Modulator for Pulsed IR Laser Radiation

We present an electrooptical modulator with a large cross-section (ø 6.2 mm) used for the SSB modulation of IR-laser radiation at frequencies in the KU-band. The development of a new laser coupler enables the simple coupling of laser radiation into the waveguide system which contains the modulator crystal. The CdTe single crystal is matched to the waveguide system by means of attached dielectrical plates ("dielectric slug") acting as λ/4 transformers. This modulator generates frequency-shifted laser pulses at a modulation efficiency of 75 %.