Electro-optic modulator for high-speed Nd:YAG laser communication

摘要

An engineering model of an electrooptic intensity modulator for Nd:YAG laser wavelength was designed, manufactured, and tested under ESA contract in cooperation with the Institut fuer Nachrichtentechnik und Hochfrequenztechnik/Technische Universitaet Wien. Two lithium niobate crystals were cascaded to constitute a traveling wave electrooptic bulk modulator. The crystals were embedded in a beryllia holding structure to guarantee mechanical alignment and good heat transfer. Electronic bias voltage control was implemented to compensate thermal disturbances and aging effects. Only materials, parts, and processes compatible with the ESA requirements for operation in space were used. The following performance data were achieved: optical transmittance greater than 86 percent, optical power handling greater than 1W cw at 1.06 micrometers, electrical bandwidth 1.8GHz, halfwave voltage 39V, extinction ratio 14dB, modulation data rate 1Gbit/s.