I’m currently working on a project with an infrared laser with a wavelength 0f 980nm. For that purpose, I’m looking for an infrared sensor which works in an area of this wavelength. Additional to that it would be great when the detection area of the sensor is as big as possible (not less than 100mm X 100mm). Has somebody an idea or can recommend some sensor?
Thanks for your support.
An array of tightly packed photodiodes or phototransistors that are sensitive to that wavelength, placed close enough together that the laser will always touch at least one when pointed at the target.
Try a horn antenna with one IR photodiode/transistor at the apex.
Additional to that it would be great when the detection area of the sensor is as big as possible (not less than 100mm X 100mm).
A large Fresnel lens suitable for visible light, focused on a single 980 nm photodiode (or perhaps a small cluster of them) should work.
You can buy Fresnel lens material in sheets like this one. The focus will be slightly different for 980 nm light than red light.
That's true only if the incoming beam is from dead ahead. For other directions the location of the focal point shifts.