Laser Resonator Life

[TOSDOC]

I've had my 15W CO2 Laser for surgeries since 2010 and it's never needed replacement or maintenance as yet. I know that laser resonators degrade over time, and was just wondering if there was any way to measure the actual power output without getting the manufacturer involved now that the warranty's expired. Does anyone know of any test for this?

[Sea Skimmer]

Thermopiles and several other forms of electronic sensor can measure the thermal output of a laser beam. Thermopiles are nice though because they'll work with both pulsed and continious wave lasers. Frankly though if your using this thing for surgeries, I have no idea what you do for a living, it seems like a real liability kind of thing to start doing home tests on equipment.

[madd0ct0r]

you could point it at a bucket of water and measure the temp change after 10 seconds. repeat a few times it'd give you an idea.

[TOSDOC]

Thermopiles and several other forms of electronic sensor can measure the thermal output of a laser beam. Thermopiles are nice though because they'll work with both pulsed and continious wave lasers. Frankly though if your using this thing for surgeries, I have no idea what you do for a living, it seems like a real liability kind of thing to start doing home tests on equipment.

Oh, crap, I don't want you to think that. I was just getting ready to choose between signing up for another 4-year service lease and going with a new laser in the 15-30W range. A drop of 1/2-1 watt I could live with over the next 4 years, I only need 8-10 on continuous or superpulse to neuter a dog, but I'm sure the company would prefer I splurge, and I wanted to see if the power output indeed matched what the console was telling me.

[Sea Skimmer]

Well if failure isn't a safety issue then I'd go look around for a thermopile or other solid state thermal sensor you can plug into a laptop. Problem is you might need software which will drive up the cost, and at least my 30 seconds of google turns up no specific sensor, though I'm sure they exist. Freaking everything exists already for thermal sensors. Question is if it costs 40 bucks or 400.

It'd be easy to devise an experiment to test the power rating if you also had a good laser to compare too, without that I'm not sure what would work with the required accuracy, heating water, melting ice, setting things on fire ect... are all pretty damn variable when one or two watts count. I don't suppose you have some spare dog flesh to singe lol?

Have you already tried looking into product reviews? You can't be the only one using them and someone else may already have done this with proper equipment. For that matter does the warranty itself say something about what it actually guarantees on power?

Gut instinct personally though would be that the thing should last a damn long time.

[TOSDOC]

Gut instinct personally though would be that the thing should last a damn long time.

This is probably what I really needed to hear.

The method I just learned to measure the effective diameter of the beam is to set it for a single 0.1 second shot at a power output of 10W, then measure the diameter of the hole it makes in a wooden tongue depressor at the focal point. If I'd known that 4 years ago I could have compared the two measurements over time. I suppose I could try heating up a bucket of water with it. Not to be grim, but a cadaver could also be cheaper than a thermopile test if the latter involves a software purchase as well, especially when there are other teaching uses for it as well.

Product reviews show this model is going out of date and style. It's an articulated arm, which is damned heavy compared to a waveguide, delicate where the mirrors are concerned, and more difficult to maintain the optimal focal distance. And its max is 15 watts, while newer models are aiming for a range up to 30 for more versatility in procedures. I won't mind trading up when it comes time, but as long as it's still working at a 10+ watt range it'll be fine for what I'm doing, and it certainly seems to be holding up.

For that matter does the warranty itself say something about what it actually guarantees on power?

Another question I'm adding to the list when I call them tomorrow.

[Luke Starkiller]

You could also look into local companies that do instrument calibration, though there would obviously be a cost with that

[TOSDOC]

I went with the service contract. It was far cheaper than the other options, though I appreciate all the input. They gave me a break on the initial inspection and servicing, and the output is fine. Next time I plan to measure the output as soon as it's out of the bubble-wrap.