In laser scanners and LIDAR systems, the environment is usually scanned with a pulsed laser beam and the reflection time of the signal from the object back to the detector is measured. The Time-of-Flight (TOF) reflection time measurement can be used over distances ranging from one meter up to several kilometers. To increase the range of the systems, very short laser pulses in the invisible NIR range are used. These enable a higher laser power compared to continuous wave lasers while still complying with eye safety requirements. During the scanning process, the systems gather individual distance points within an aggregate of points, from which three-dimensional images of the environment can be computed. The laser scanners deflect the laser beam using deflecting mirrors, which enables them to achieve very wide fields of vision. Some LIDAR systems also rotate around their own axis and offer 360° all-round visibility. Modern devices achieve very high data rates with over one million distance points per second.
For measuring systems based on the reflection time process using light pulses of varying intensity in the nanosecond range, First Sensor offers highly sensitive avalanche photodiodes with internal amplification across a wide dynamic range as well as wide bandwidths. To achieve the high spatial resolutions required in optical LIDAR systems, First Sensor develops APD arrays that consist of multiple sensor elements using, for example, 8, 16, 5x5 or 8x8 pixels. For the matrix arrays, development modules that simplify the process of testing the detector are also available.