| Popis: |
We have successfully tested 5 to 8 GHz bandwidth, uncooled, Extended InGaAs 2.2 μm wavelength, linear optical receivers, coupled with single mode fibers for 30 MeV Protons, Gamma rays, 1 GeV/n Iron ions, and 1 GeV/n Helium ions. These devices find multiple applications in outer-space for coherent rapid Doppler shift LIDAR, long wavelength gravitational wave sensing, as well as inter-planetary and Earth-to-Moon coherent communication links. Nine devices comprising of Extended InGaAs 2.2 μm PIN photodiode (PD) and GaAs transimpedance amplifiers (TIA), coupled with single mode fibers, were tested with 30 MeV protons, three each with fluence levels of 4.9 × 1010 cm-2 , 9.8 × 1010 cm-2, and 1.6 × 1011 cm-2 . Three more devices were tested using 1.4 ♦ 108 Helium ions/cm2 at 1 GeV/n over a six minute exposure for a dose of 20 rad (water). Three additional devices were exposed to 1 GeV/n Fe fluence of 2.8 × 105 ions/cm2 for half a minute delivering a dose of 6 rad (water). Another three Extended InGaAs PD and GaAs TIA fibered devices were tested using Cesium-137 gamma rays of 662 keV for 15 krad (water). Pre- and post-radiation results were measured for (1) dark current vs. voltage for the InGaAs photodiodes, (2) responsivity (quantum efficiency) for the photodiodes, (3) optical return loss for the photodiodes, (4) TIA drive current, (5) bandwidth of the PIN + TIA, (6) conversion gain of the PIN-TIA, and (7) Bit Error Ratio (BER) of the PIN-TIA for 10.709 Gbps NRZ-ASK signal. All devices were found to be fully functional at normal operating conditions and at room temperature. All these efforts will advance the Technology Readiness Level (TRL) of these devices by year 2020. |
