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Abhay M. Joshi1, Shubhashish Datta1, Ryan Miller1, Nilesh Soni1, Matthew D'Angiolillo1, Jeffrey
Mertz1, Michael Sivertz2, Adam Rusek2, and James Jardine3
1 Discovery Semiconductors Inc., Ewing, NJ, USA
2 NASA Space Radiation Laboratory, Brookhaven National Laboratory, Upton, NY, USA.
3 Brookhaven National Laboratory, Upton, NY, USA.
ABSTRACT
We have successfully tested 10 GHz bandwidth, uncooled, linear InGaAs optical receivers, coupled with a standard single mode fiber for proton and gamma rays. These devices find multiple applications in space for inter-satellite optical communication links, rapid Doppler shift lidar, as well as inter-planetary and Earth-to-Moon communication links. Nine InGaAs PIN photodiode and GaAs transimpedance amplifiers (TIA) were irradiated with 100 MeV protons with a fluence level of 1.6 × 1011 cm-2 corresponding to a total dose of 19.1 krad (water). Devices were also subjected to 30 MeV protons, six each with fluence levels of 4.9 × 1010 cm-2, 9.8 × 1010 cm-2, and 1.6 × 1011 cm-2. Additionally, another nine InGaAs optical receivers were irradiated with 662 keV gamma rays, three devices each for a dose of 15 krad (water), 30 krad (water), and 50 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 at 1550 nm wavelength, (4) drive current of the TIA, and (5) bandwidth of the PIN + TIA. All devices were found to be fully functional at the normal operating conditions and at room temperature.
INTRODUCTION
Photodetectors have been deployed in satellites for low-speed passive sensing applications for decades. Photonics is expected to encroach on traditional microwave applications and significantly expand its role in space platforms. These applications include ultra-fast optical communication links, high-speed lidar sensors, and photonic clock generation, to name a few. Although photodetectors are available to address similar terrestrial applications, there is a dearth of space qualified counterparts that can withstand the harsh environmental conditions of space, in part due to the comprehensive radiation testing needed to guarantee a successful space mission.
The paucity of radiation test results for photonic components is complicated by the diversity of space environments, as detailed in Ref. [1]. For example, proton radiation testing may be the most crucial test to qualify a device for a Low Earth Orbit (LEO) mission. These devices must survive displacement damage and ionization damage from Earth's proton belt, especially at the South Atlantic Anomaly. In contrast, solar flares and Galactic Cosmic Rays (GCR) containing heavy ions must be considered for geosynchronous orbits and outer space missions. These high-energy ions are not as plentiful as protons but may cause single event upsets. Additionally, interplanetary missions require testing as per the targeted planet's radiation environment, which may be significantly more stringent than that of Earth, e.g. Jupiter [1]. Added considerations of mission life, operating conditions (device bias, temperature), and spacecraft design (shielding) dictates that a device be tested extensively for various types of particles for different doses before it is deemed suitable for inclusion in a space mission.
In this work, we present a 10 GHz bandwidth, uncooled, linear InGaAs photoreceiver, coupled with a standard single mode fiber, which has passed 100 MeV proton radiation up to a fluence of 1.6 × 1011 cm-2; 30 MeV proton radiation up to a fluence of 1.6 × 1011 cm-2; and 662 keV gamma radiation up to a dose of 50 krad (water). Additional radiation test results for these devices when subjected to 1 GeV/n Fe ions and 1 GeV/n He ions will be published elsewhere.REFERENCES
- [1] A. Johnston, "Radiation Effects in Optoelectronics Devices," IEEE Trans. Nuclear Science, vol. 60, no. 3, pp. 2054 - 2073, 2013.
Event: SPIE Defense + Commercial Sensing, 2019, Baltimore, Maryland, United States
