Hello and introduction

[Aberration]

After lurking for a bit I finally registered. I love lasers, but buying a personal one was not my intention when I found this site.

I work in photo-lithography. We use big DUV lasers, 193nm and 248nm. The biggest I have worked on is a Cymer XLA200. Can I claim class 4 for that

So for my work we were looking to devise a system to align to large optical elements. Normally it is done with this big jig of micrometers but that is really expensive to have made. So I have a personal 5mW He-Ne that I used to see if optics would pass other than UV, and sure enough worked great.

We didnt want to use a HeNe because they are big, replacement could be a pain and all that. So for our application I found a green diode that is focusable, and a cross generating grating.

But of course once you start looking into lasers you just cant stop. So the HeNe is fun to play with, but I think I will eventually get something a bit bigger.

I think I just may end up building my own. I would really like the experience of doing everything. Getting the IR diode, the crystals and aligning it all myself.

So if anyone has any good suggestions, I dont want to just get a module and put it in a host though, that just too simple.

 

[jwc]

Welcome to the forum! It sounds like you work with some interesting systems.

Building a green laser in the manner you describe is perfectly possible, but it will take time (sounds like you're interested in it as a project, not just the end result, so that's not an issue) and some good machining.

Personally, I'm currently drawing up the plans to build a homemade DPSS labby this January. I have a set of unbonded, rotationally pre-aligned, large crystals originally from a portable laser pointer. The original pump diode was 2W and it yielded about 200mW of output with only the passive cooling of a portable host.

This January, I'm planning to machine some heatsinks for the crystals and a new diode. The Nd:YAG crystal will be cooled with a TEC that will have circuitry to achieve temperature stability. The KTP crystal will be heated with a heating element.

Through good temperature control, it is possible to find the peak efficiencies of each crystal and stabilize their temperatures. At first, I'll probably just wire up some simple analog control circuits (mosfet, pot, thermistor, etc.) capable of handling rough temperature control, but I want to actually pipe the thermistor output into a microcontroller and do the temperature stabilization there. I've been discussing this with BlueFusion a lot and he suggested wiring up my power meter so that the microcontroller can automatically tune the temperatures for maximum power output. Based on the research I've done, I think that 20% efficiency should be a reasonable goal.

However, I'm not a very good mechanical engineer, so machining good heatsinks won't be too easy for me. Fortunately, I know a lot of meche's, so hopefully they can help me out.

But of course once you start looking into lasers you just cant stop.

Figuratively, yes. Literally... well, let's hope not!

 

[Aberration]

Since I have not delved into it all yet....

But I would look at some computer heatsinks. There are tons of small ones for GPU RAM and such.

 

[Helioplasma]

Welcome to the forum .

Check for mauswiesel posts, he built a working DPSS laser with a 1W c-mount and achieved 1-10mW. Takes a lot of time and courage though good luck .

 

[Aberration]

Thanks I will look for his posts.

Considering the machine I work on, I am not too worried about the time and patients thing.

 

[laserspaces]

Hey,I also love lasers and I have worked on lasers for more than 4 years.
But we mainly work on the portable lasers like 532nmlaser pen,powerful green laser pointers,473nm laser pointers,405nm laser pen,650nm laser pointers,DPSS lasers and so on

 

[Aberration]

Nothing like working on a big DUV laser. Those big ones can do 4KHz pulse rate, but even at 50Hz it will instantly burn clean room paper (plastic). Sometimes we got a problem tool that takes a while to do alignment. You will get done and look like you went skiing, a little burnt around your goggles.

When we get new guys they always ask, if its UV and we cant see it why does the beam look blue?

Well the air is made of ~70% nitrogen....

 

[LarryDFW]

Hi Aberration;

Welcome to the board.

Do you work for Cymer?

You should have some good optical experience.

LarryDFW

 

[Aberration]

Nope just use them as a light source. Gigaphoton also. I have had some training from Cymer though. You really dont end up doing much with optical alignment for them. And then aligning beam tube also that has halving optics and mirrors. Beam expanders, other optics to keep the beam uniformity as best as possible, some to adjust for telecentricity. Most of the stuff is documents maintenance, and we dont get the theory and all behind the optics.