Hey everyone! I'm exploring the idea of detecting a low-power red laser beam with these specs: around 650 nm wavelength (which is visible red light), power ranging from 10 mW to 30 mW, and a beam diameter of 3 mm. My main goal is to identify the presence of this laser beam using a device like a sensor or a camera, even if the beam itself isn't visible to the naked eye. Do you think it's possible to set up such a detection system? Thanks!
3 Answers
Have you thought about looking into laser-tag systems? They could have some insights or technology that might help with your project!
Absolutely! You can set up a photodiode to detect the laser beam. When the laser hits the diode, it can generate a signal that you can read via GPIO or an ADC. Just a heads up: you’ll need enough power to reach the sensor; otherwise, it won't work as you expect. For silicon sensors, around 5mW could generate about 2.5mA of current, which, when used with a 1K resistor, gives you a 2.5V signal. Pretty straightforward!
Thanks for the info! Just to clarify, I want to detect a low-power red laser traveling inside a closed cable, so it isn’t visible. Is there a way to detect it externally with a sensitive sensor?
You can totally use infrared receivers with red lasers. The trick is to modulate your laser beam at a specific frequency, around 38 KHz, to ensure it's properly identified by the receiver. It’s similar to how garage doors detect objects under them with lasers. Just something to consider!
Thanks for the suggestion! I'm still looking for ways to detect a low-power laser beam inside a cable without disconnecting it. If you have any specific ideas or sensors in mind, I'd love to hear them!