World’s first SPAD image sensor with on-chip photon processing debuts

Edinburgh-based semiconductor company Singular Photonics has launched Litavis, a new image sensor designed to combine photon counting, timing and statistical analysis directly on a single chip. The company describes Litavis as the world’s first single-photon avalanche diode (SPAD) sensor with in-pixel processing capable of combining imaging, timing, histogramming and photon statistics on the same device. Rather than sending large quantities of raw photon data to an external processor, Litavis performs part of the analysis inside the sensor itself. Singular Photonics says this can reduce data transfer requirements and enable lower-latency, more power-efficient imaging systems. A camera that can do more than measure light SPADs are designed to detect individual photons, making them particularly useful when extremely low light levels or precise measurements of photon arrival times matter. Litavis builds on that sensitivity by making the sensor software-configurable. The same hardware can be reconfigured for different imaging tasks without requiring a new sensor design. Its operating modes include photon-counting imaging, programmable time gating, multiple time-to-digital converter (TDC) configurations, time-correlated single-photon counting (TCSPC), coincidence detection, and combined timestamping and imaging. This allows the sensor to capture not only how much light reaches each pixel, but also information about when photons arrive and how those events are distributed over time. That additional information can help be applications where conventional intensity-based imaging is not enough. Processing photon events on the chip Litavis uses a CMOS SPAD architecture with digital photon processing integrated directly within the pixel array. The sensor provides continuous 256 × 256-pixel photon-counting imaging under low-light conditions. At the same time, it can generate timestamped photon events on a 64 × 64 macropixel grid, providing picosecond-resolution timing alongside the full-resolution photon-counting image. The device also supports multi-event timing, allowing multiple photons detected during an excitation cycle to be individually assigned to time bins. Its in-pixel histogramming capabilities can then be used to analyze the statistical distribution of those photon events. This opens possibilities beyond conventional camera images, including measurements used in fluorescence lifetime imaging, dynamic light scattering, and quantum sensing, according to Singular Photonics. The approach also addresses a practical problem that can become significant as imaging systems collect more data. Instead of transferring every detected photon event to another processor for analysis, some processing happens within the sensor itself. Singular Photonics says this can reduce the amount of raw data that needs to move through the system, potentially improving latency and power efficiency while allowing real-time processing to scale more effectively. One sensor, multiple applications The company is positioning Litavis as a flexible platform rather than a sensor designed around one particular application. Potential uses include machine vision, robotics, physical AI, depth sensing, spectroscopy, scientific and medical imaging, quantum technologies and industrial automation. The software-configurable architecture is intended to let developers and system integrators experiment with different acquisition and timing modes using the same hardware. That could reduce the need to develop separate sensor architectures for different applications and shorten development cycles. “Litavis combines the sensitivity advantages of SPAD technology with the adaptability and scalability increasingly required by modern multimodal imaging,” said Shahida Imani, CEO of Singular Photonics. Singular Photonics says it has already received significant pre-orders from companies and institutions internationally. The company plans to demonstrate Litavis at SPIE Sensors + Imaging in Edinburgh and later at VISION in Stuttgart, giving developers an opportunity to see the sensor’s multimodal capabilities in operation. Instead of treating the image sensor as a device that simply captures photons and leaves all interpretation to a computer, Litavis attempts to move some of that intelligence into the sensor itself. Get the latest in engineering, tech, space & science - delivered daily to your inbox.Kaif Shaikh is a journalist and writer passionate about turning complex information into clear, impactful stories. His writing covers technology, sustainability, geopolitics, and occasionally fiction. A graduate in Journalism and Mass Communication, his work has appeared in the Times of India and beyond. After a near-fatal experience, Kaif began seeing both stories and silences differently. Outside work, he juggles far too many projects and passions, but always makes time to read, reflect, and hold onto the thread of wonder.