This project will investigate innovative ways to realise single photon visible light imagers for a number of applications in astronomy, quantum technologies, autonomous systems, and life sciences. The main objective is to create image sensor designs suitable for adaptive optics systems and low-light level spectroscopic and imaging applications, based on detailed semiconductor and technology device simulations. By detecting and counting each and every photon without any additional noise, these sensors could offer the ultimate performance in imaging, and help us see and discover the unknown.
The work will pursue single photon, visible light imaging capabilities in Complementary Metal Oxide Semiconductor (CMOS) image sensors without the use of avalanche electron multiplication due to the inherent high power dissipation and spurious charge generation in such devices. Instead, we will focus on increasing the conversion gain in pixel and averaging of multiple independent signal samples, combined with low noise readout methods to reduce the effective noise to below 0.1 e- rms. This level of noise is needed to reduce the probability of spurious signals to acceptable levels in large image sensor arrays, making reliable single photon detection viable.
We have identified a number of highly innovative solutions, which will be investigated using semiconductor device simulation and technology computer aided design (TCAD) tools. The pixels with the highest potential to achieve the required noise performance will be brought up to detailed designs, which can be manufactured and tested in the following phase of the ATTRACT programme.
Large area CMOS image sensors with deep sub-electron readout noise and high frame rate would offer breakthrough performance for many applications. The main advantage is the ability to perform detection of individual photons without spurious signals, and to perform image reconstruction by counting the photons detected in each pixel without any additional noise. Also, the sensors are expected to require little or no cooling, and to have low power dissipation. The imaging performance of such sensors would be limited only by the photon absorption in the semiconductor and the quantum nature of light. The results of this project are expected to lay the foundations for transformational changes to low light imaging in science and technology.