Power meter for physics experiment.

hey guys a friend and I are doing a physics experiment and surprise surprise were thinking of using lasers. what im wondering is what would be a reasonably cheap laser power meter that i can get hold of in australia. The laser being used will be approximatly 100mW so it dosent need to be amazingly accurate however still accurate enough for dependable and consistant results. thanks guys

Try reading the voltage differential from a silicon solar cell - when you hit it with the light, it will produce power I dunnot if you will get any DECENT results...

I would suggest the same thing as well... The prices for a laser power meter are still way out of reach for even most enthusiasts. The cheapest one that I know of and is reliable enough is the LPM-1 from Andover Holography. The best way to get it is to contact the seller directly, and that would be a user by the name "Tony_and_holo" (remove quotes). The thing is prices at $200 and would measure up to 100mW I think, but you can extend this range to about 1W using the ND filter they sell for $40. I honestly believe this would be your best bet as this is the cheapest option and the most reliable for the money. Your other option is to get a LaseCheck from Coherent for about $300-400...

GL and hope it's not a necessity;
DDL

If memory serves, don't diodes produce current when exposed to light? Like a micro-power solar cell... The thing is, with an LED, the thing should be selective with regards to color.

If you're testing a red LASER, you'd have to use a red diode. That kind of thing.

Not sure how well it would work, but there used to be a circuit for this type of thing in the old Forrest Mims books at Radio Shack.

-- Chuck Knight

Chuck - some have had moderate to aweful results with the LED power meter experiments. That COULD work (never did for me, unfortunately) if you already had verified power readings for your laser to compare the results to.

Here is an interesting link : http://www.cat.ernet.in/others/lasinfo/p-meter.html

Didn't someone mention measuring horsepower with one's Glutious Maximus?

This is probably as effective...
DDL