1
$\begingroup$

In Photography SE I've just asked LIDAR burnout; ways to check for damaging infrared lasers before shooting besides looking for posted warnings? and discussed a camera that was damaged by a self-driving car's LIDAR system at the recent CES show.

The article linked there mentions the powerful "fiber laser" used by that car's LIDAR system. For those I normally think of infrared wavelengths around 1500 or 1600 nm used in communications, but for simple semiconductor lasers based on III-V material the wavelengths are often around 800 or 900 nm.

This is just from personal memory. I'm wondering if I've got it right, and/or if there are other sources for common laser wavelengths used in obstacle detection and ranging.

$\endgroup$
2
$\begingroup$

You are correct. Most Velodyne LIDARs (very commonly used on autonomous vehicles), use 905 nm diode lasers, and so do many Hokuyo laser scanners and SICK LIDARs.

A new company, Ouster, uses 850 nm lasers, claiming that their choice of lower wavelength is because the "atmospheric water absorption is orders of magnitude lower than at 905nm".

Some more info: https://velodynelidar.com/newsroom/guide-to-lidar-wavelengths/

| improve this answer | |
$\endgroup$
  • $\begingroup$ Please accept the answer if you think it has answered your question adequately. $\endgroup$ – HighVoltage Feb 15 '19 at 1:58
2
$\begingroup$

Both 1550nm and 900nm ranges are used in different lidars.

Velodyne and majority others use 905nm lasers because these diodes are really cheap.

1550nm are used when there is a need for very long distance measurement range, such as Luminar, as the eye safety threshould is several orders of magnitude higher for this wavelength than 905nm.

In principle, the laser has to be very very high power to distroy a camera. Unfortunately most of these lidar start-ups are still in developing phase, and the so called Class 1 is the goal to achieve. Be careful not to look at the start-up's lidars.

| improve this answer | |
$\endgroup$
  • $\begingroup$ Thank you for this advice "do not look at the start-up's invisible light rays when there are no warning signs" ;-) $\endgroup$ – uhoh Jan 17 '19 at 18:38

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.