Sometimes a laser is used in a “pass-through” setup, which begs the question: What happens to the laser after it passes through?

Consider for example a sensitive camera that is used to profile a laser. Beam splitters are often used to deflect only a small percent of the laser intensity into the camera. The other 90% or more passes straight through the splitter.


Lasers are famous for their focusability. (As in: “laser-focus.”)

That’s why many laser power sensors have 30, 20, or even just 10 mm apertures. This is usually more than enough space for a laser beam.

But what about large lasers like diode stacks or non-laser light sources? How can a small sensor measure a large laser beam?


With high power lasers, there’s always a safety concern for equipment and people nearby.

(Of course, I’m not qualified to give a detailed analysis of what needs to be taken into account for laser safety. For that, you should consult a laser safety officer.)

I want to specifically ask whether there’s an issue of laser light reflecting off power measuring equipment.