Is building a femtosecond laser within the reach of a hobbyist?

October 13, 2008 2:24 PM

Is building a femtosecond laser within the reach of hobbyists?

I've noticed an interesting number of research projects lately that utilize femtosecond lasers. I've found Sam's Laser FAQ, but the question is left somewhat unanswered. Is building a femtosecond laser within the reach of a hobbyist? What's the major cost in building hobby lasers? (Please no lectures on whether this is a good idea or how I might rip a hole in the space time continuum).

posted by arimathea to Technology (2 answers total)

It’s surprisingly easy to do. In my old lab, we had people with no experience put one together a couple of weeks; if you know what you’re doing, you can make one in a few hours.

To make a fiber laser, pretty much all you need is a source, some polarization maintaining fiber, some dispersion compensating fiber, some doped fiber, a couple of couplers, and a couple of adjustable polarizers. I never paid attention to cost when I was a grad student, and I work in a different area now, but I don’t think any of those things are prohibitively expensive. And now that I think about it, you can probably get way without using PM fiber and replacing most of that with a mirror, if you don’t need a really short pulse. I think it would be a lot more expensive to work in free space (instead of fiber), but I don’t really know. Maybe someone else can chime in about that.

The problem is that you’d need access to fiber splicing equipment to assemble things, and a broadband optical spectrum analyzer, to tune your laser until it’s mode-locked. I think the OSA we had in our lab cost around $100k. Ebay has some that are a lot cheaper, but they’re still pretty expensive.

If there’s a school with a big EE, ME, or Applied Physics department nearby, they should have all of the expensive equipment that you’ll need. You might be able to get access by signing up for the right class.
posted by suncoursing at 3:55 PM on October 13, 2008

You can buy kits for them. I don't see prices on there but a friend of mine bought one a couple years ago and I remember it was $30-$50k range.

See also: this and this.

If you have previous experience working with optics it's probably not too hard (although my friend had to recruit someone from Stanford Physics to get his working reliably) but if you've zero optical experience I think it will be pretty tough.
posted by pombe at 5:25 PM on October 13, 2008