Sony announced the AS-DT1, the world’s smallest and lightest miniature precision LiDAR depth sensor.
Measuring a mere 29 by 29 by 31 millimeters (1.14 by 1.14 by 1.22 inches) excluding protrusions, the Sony AS-DT1 LiDAR Depth Sensor relies upon sophisticated miniaturization and optical lens technologies from Sony’s machine vision industrial cameras to accurately measure distance and range. The device utilizes “Direct Time of Flight” (dToF) LiDAR technology and features a Sony Single Photon Avalanche Diode (SPAD) image sensor.
As Sony Semiconductor Solutions Corporation describes, a SPAD sensor promises exceptional photon detection efficiency, ensuring the sensor can detect even very weak photons emitted from the light source and reflected off an object. This efficiency is crucial, as reflected light is precisely how LiDAR works. Light Detection and Ranging (LiDAR) measures distances by measuring the time it takes for emitted photons to bounce off an object and return to the sensor. The more efficient the image sensor in terms of photon efficiency, the better its accuracy.
Compared to the CMOS image sensors that photographers are familiar with, which detect light by measuring the volume of light that accumulates inside individual pixels over a specified time frame, SPAD sensors can detect a single photon — SPAD sensors digitally count photon particles without accuracy or noise issues. SPAD image sensors are fundamentally different and significantly more efficient than CMOS sensors.
So why don’t all cameras use SPAD sensors? While they are very good at measuring single photons, they are not well-suited to measuring much more light, which nearly everyone wants to capture with a traditional camera. They are also costly, not high resolution, and inflexible. It was big news when Canon unveiled a one-megapixel SPAD sensor less than five years ago, to help illustrate where the technology is in terms of resolution.
Sony does not say much about the specific SPAD sensor in its new AS-DT1 LiDAR Depth Sensor. There aren’t many SPAD sensors in Sony’s sensor catalog, but the few that are there are small and have relatively few pixels.
Nonetheless, Sony is high on its new AS-DT1 device. Due to its small size and impressive SPAD sensor, the company says it is “ideal for applications where space and weight constraints are paramount, including drones, robotics, and more.” It is reasonable to suspect the device could also be helpful in self-driving cars. Any situation needing very accurate depth and distance measurements in challenging lighting scenarios is well-suited to something like the AS-DT1.
“The AS-DT1 can measure distances to low-contrast subjects and objects with low reflectivity, which are more difficult to detect with other ranging methods. This enables accurate measurement of distances in diverse environments, such as retail stores, where various objects, including people and fixtures, are expected,” Sony explains.
“In addition to its ability to accurately measure distances both indoors and outdoors, the sensor’s compact, lightweight design and rigid aluminum housing allow for integration into a wide range of devices, such as food service robots in restaurants, autonomous mobile robots in warehouses, and drones used for inspections and surveys.”
The Sony AS-DT1 can measure at various distances with exceptional accuracy. For example, Sony claims it can measure the distance to objects 10 meters (32.8 feet) away with a margin of error of five centimeters (nearly two inches) indoors and outdoors. The company further claims the AS-DT1 is superior to competing imaging devices when dealing with low-contrast subjects, objects with low reflectivity, and floating objects.
The AS-DT1 can accurately measure up to 40 meters (131.2 feet) indoors and 20 meters (65.6 feet) outdoors under bright summer conditions, which Sony says can be challenging “when inspecting infrastructure such as bridges, highways, and dams.” Given its small size and how valuable drones are for infrastructure inspection, this is a particularly attractive use case for the AS-DT1.
Sony expects the AS-DT1 to be available in Spring 2026. A prototype will be debuted to the public at Exponential in Houston, Texas, May 20-22, 2025. It is an extremely specialized type of camera, but it is always interesting to see the latest advancements in image sensor technology.
Image credits: Sony
