Question: How can lasers detect light?

Ian Sandal answered on 14 Mar 2015:

The simple answer is they can’t. A laser converts electrical energy into light so it makes light rather than detects it.

However this process can be reversed so if we shine light on it the light energy can be converted into electrical energy that we can detect. A solar cell works in this way. But to make these devices as efficient as possible we need to design them in different ways, so we could use a laser to detect light or as a solar cell but it wouldn’t work very well.