VARIAN ASSOCIATES INC PALO ALTO CA LIGHT SENSING AND EMITTING DIV
This report describes the results of work performed under this contract the original purpose of which was to design and develop high speed 1.06 micron sensitive static crossed field photomultipliers. As a result of two program modifications, this contract successfully developed two different static crossed field photomultipliers SCFPs. The end use of such devices would be their incorporation into gigabit laser communication systems as optical receivers. The first development of this three-phase program was a high output current 250 microamp four-stage device which features 120 picosecond rise and fall times, a 3-gigahertz bandwidth, 1000 gain, and either S-20 or 1.06 micron InAsP photocathodes achieving 7 quantum efficiency at 5000A and 1.4 quantum efficiency at 1.06 microns. The second development was a 250 microamp output current, six-stage SCFP achieving 100,000 gain at 150 picosecond rise and fall times 2.5 GHz bandwidth and incorporated GaAs 0.53 micron photocathodes which achieved 18 quantum efficiency. Excess noise for these devices was less than 1 dB. Finally, 0.53 micron GaAs photocathodes were incorporated into 250 microamp output current four-stage devices with the same gain and bandwidth as achieved in the first development. Quantum efficiencies of 22 at 0.53 micron were produced as well as high gain gallium phosphide dynodes and excess noise of less than 0.4 dB.