Re: Detecting Laser Diode?
If you stick to class-1 lasers (the average banned laser pointer), you shouldn't have any problems. Those don't have enough power to damage a human eye with extended exposure, even when run through a focusing lens, so they shouldn't hurt a photosensor.
As for sensors, you have a range of options. A CdS photoresistor will work, but so will photodiodes, phototransistors, and the everyday red LED. CdS is losing popularity because it's toxic, so I'd suggest going with silicon unless you already have the CdS on hand.
Silicon devices will definitely stand up to a laser because they use the photoelectric effect. All silicon devices are photosensitive, and sensors are just designed to take the best advantage of it. LEDs make decent sensors because the math works both ways.. putting current through the junction generates light, and putting light into the junction generates currrent. They work best for wavelengths close to the ones they emit, so if you have a red laser pointer, try shining it on a red LED and see what kind of response you get.
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