Space Qualification of 5 to 8 GHz Bandwidth, Uncooled, Extended InGaAs 2.2 Micron Wavelength, Linear Optical Receivers (2019)

Abhay M. Joshi¹, Shubhashish Datta¹, Nilesh Soni¹, Matthew D'Angiolillo¹, Jeffrey Mertz¹, Michael Sivertz², Adam Rusek², James Jardine³, Sachi Babu ⁵, and Peter Shu ⁴
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.
⁴Newton Engineering and Product Development, Greenbelt, MD, USA.
⁵NASA Earth Science Technology Office, Greenbelt, MD, USA.

ABSTRACT

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.

INTRODUCTION

Comprehensive space qualification of Extended InGaAs Photodiodes and Photoreceivers with wavelength coverage in the Short Wave Infrared (SWIR) from 1 µm to 2.5 µm wavelength is urgently needed for multiple space based applications such as: (1) coherent LIDAR having rapid Doppler shifts for wind profiling; (2) direct detection of backscattered sunlight for spectroscopic sensing of greenhouse gases; (3) next generation of space telescopes that peer into the SWIR; (4) long wavelength gravitational wave sensing; and (5) free-space optical communication links with bandwidths up to 400 Gbps.

Although Mercury Cadmium Telluride (MCT) has been the predominant material of choice for SWIR space based applications for the past several decades, especially the infrared Focal Plane Arrays (FPAs), it has several deficiencies in meeting the needs of multiple space applications other than the FPAs. Thus, qualifying Extended InGaAs Photodiodes and Photoreceivers for the harsh radiation environment of space is vital for assuring successful space missions having multiple applications with mission life up to 10+ years. With this objective in mind, we have undertaken a detailed and comprehensive multi-year effort to test Extended InGaAs devices and have them space flight ready in the near future.

We present in this paper radiation tests that not only include 30 MeV Protons and 15 krad Gamma Rays which are sufficient for Low Earth Orbit (LEO) space crafts, but also 1 GeV/n Helium ions, and 1 GeV/n Fe (Iron) ions, which constitute the key components of the Galactic Cosmic Rays (GCR), thus, assuring reliable functioning even in the outer space outside of Earth's protective magnetosphere. All radiation tests were carried out at room temperature (~20 °C) and devices were unbiased during the radiation exposure. We measured pre- and post- radiation device characteristics at room temperature. It has been shown that the displacement damage is the key failure mechanism in InGaAs/InP photodiodes and avalanche photodiodes, and is independent of the in-situ biasing of the devices during radiation [1 - 3].

Our radiation tests show no major evidence of displacement damage in Extended InGaAs devices that can compromise their proper functioning in space.

REFERENCES

[1] A. Johnston, "Radiation Effects in Optoelectronics Devices," IEEE Trans. Nuclear Science, vol. 60, no. 3, pp. 2054 - 2073, 2013.

[2] A. Joshi, S. Datta, R. Miller, N. Soni, M. D'Angiolillo, J. Mertz, M. Sivertz, A. Rusek, and J. Jardine, "Proton and Gamma Radiation Testing of 10 GHz Bandwidth, Uncooled, Linear InGaAs Optical Receivers," Proc. SPIE, vol. 11017, paper 110170D, 2019.

[3] H. Becker and A. Johnston, "Dark Current Degradation of Near Infrared Avalanche Photodiodes from Proton Irradiation," IEEE Trans. Nuclear Science, vol. 51, no. 6, pp. 3572 - 3578, 2004.

Event: SPIE Optical Engineering + Applications, 2019, San Diego, California, United States

Related links: Space qualification of 5 to 8 GHz bandwidth, uncooled, extended InGaAs 2.2-micron wavelength, linear optical receivers (2019)