LIDAR detectors are essential for both the spaceborne and airborne systems in many NASA missions. Detectors working at 1064nm wavelength are particularly important to work with YAG-based lasers, the main light source in operation. Therefore, NASA has identified the need of a 1064nm detector with enhanced photon detection efficiency (PDE), low dark noise, and low excess noise.
To achieve the goal, Imaging Nanosystems proposes a device that employs the Cycling Excitation Process (CEP), a highly efficient carrier multiplication process to amplify the photocurrent. The device combines (i) a thin layer of disorder material as the CEP gain medium deposited directly on (ii) an InGaAsP light absorption layer, and (iii) using a conduction band offset epitaxial stack to produce the properties of self-quenching and self-recovering, thus saving the need for active quenching circuits.
In this Phase I program, we will design a single photon detector based on the analysis of the absorption layer combined with the CEP gain medium by 1D and 2D simulations. The 1D simulation would complete the device structure with all layers, and the 2D analysis would consider the mesa height, field distribution, gain uniformity, and any field-crowding effect which may introduce early breakdown and gain nonuniformity. Additionally, a simple prototype device, integrating the gain medium layer with the light absorption layer, will be designed, fabricated and characterized to demonstrate single photon detection capability and low dark count rate.
The proposed detector is suitable for 1.064um space-based cloud profiling lidar applications. With high timing resolution and single photon detection it would find use in atmospheric profiling, planetary surface mapping, and vegetation/canopy lidar. Another application is 3D imaging flash lidar technology in NIR wavelengths, which can provide precision and hazard avoidance capabilities for landing missions to the planetary bodies and enable spacecraft autonomous rendezvous and docking with satellites or asteroids (e.g. in the Artemis program).
The high sensitivity, low noise detectors will serve applications in 3D sensing, LIDAR receivers, quantum communication and computation, night vision, deep space communication, and biological and medical imaging. The LIDAR receivers can be used for DOD (e.g. military autonomous vehicles, target identification) and commercial (e.g. autonomous driving, consumer devices) applications.