Full field image ranger hardware

We describe the hardware designed to implement a full field heterodyning imaging system. Comprising three key components - a light source, high speed shutter and a signal generator - the system is expected to be capable of simultaneous range measurements to millimetre precision over the entire field of view. Current modulated laser diodes provide the required illumination, with a bandwidth of 100 MHz and peak output power exceeding 600 mW. The high speed shutter action is performed by gating the cathode of an image intensifier, driven by a 50 Vpp waveform with 3.5 ns rise and fall times. A direct digital synthesiser, with multiple synchronised channels, provides high stability between its outputs, 160 MHz bandwidth and tuning of 0.1 Hz.