Thursday, October 25, 2007

DIY Green laser pointer power meter

Here is a simple cheap and accurate way to measure laser output power.

Required material :
- A green LED like this :

- An ammeter with a 1000mA range
Connect the ammeter to the LED as shown in diagram.

Place the LED into the hole of the laser head, fire the laser and read the value on the ampmeter. Use this formula to obtain the optical power : P = uA / 2.8

Note : it must be a green coloured LED for correct values (not a transparent green LED). Radio Shack sells them.

Readings : 14 uA for 5mW, and my pointer measured 310uA for 110 mW


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