Laser Beam Profiling and Monitoring Using SWIR Cameras
Monitoring laser beam shape and size is important for the various applications that depend on those lasers. For those applications that use infrared lasers, most commonly, the wavelength range is in the SWIR which is eye-safe and lower power compared to visible and NIR lasers.
The key requirements of the camera for this application is to have 60 to 100Hz frame rates to get good “live” feedback from the laser. Typically, you don’t need as many pixels for the alignment process so a 320×256 type sensor is sufficient, which allows for a lower system cost.
While sensitivity is not really required for this application, a large dynamic range is desired since you want to avoid saturation at any point in the image. This is usually achieved with a larger pixel, hence a larger full well.
One additional item that is useful for this application is the absence of a cover glass over the sensor, since reflections off this surface can cause interference in the desired signal. While this is not required for all laser beam profiling and monitoring applications, it is preferred.
For the laser beam profiling, an excellent camera would be the Bobcat 320 Series
- Series for these reasons:
- 320×256, running at 100FPS
- 16 Bit Dynamic Range
- Economical solution
- GigE interface for ease of use
- Bobcat 320 Series Datasheet
- Product information/quote
Finally, in some specialty applications, where the laser is used to measure the Time-of-Flight to perform LIght Detection And Ranging (LIDAR), you need to be able to gate the exposure to a very short time period. This requires a very specialized detector which can gate down to 100nsec exposure times and has a triggering function with low latency.