Author Options:

Variable wave laser devices? Answered

Are there any lasers available to the general public capable of changing wavelength? If so, where can I get one? Is there an easy way to make one?


You can certainly buy tunable lasers, but they're pricey (since the target market is industry and scientific R&D).

If you want to try to make one yourself, you probably can; dye lasers are a DIY option. The Wikipedia article has some external references which may be useful.

I may just have to try making 3 diode lasers focus into one beam. I want to make a color changing laser with a coherent beam, but I'm not sure if I can make a tunable laser.

Scientific American did it in the much-missed Amateur Scientist column


Best Answer 7 years ago

A Google search for DIY tunable laser was quite successful, and on the second page of results turned up the Amateur Scientist column Steveastrouk mentioned.

$75 back in 1970 is probably a few hundred bucks now (allowing for both inflation and reduced component costs).

Any time you have a question with clear "keywords," Google should be the first place you go.

Well guys, I'm just going to use dichrotic reflectors to combine different colored laser beams into one. By controlling their brightness individually, I can control the color of the combined beam. I may do this with an Arduino to save presets.

You can modulate a laser beam with sound. Effectively your making the wave length / frequency change.

If you mean change colour as far as I know the answer would be no.

+1. You can pulse a laser, but it will still have the same underlying frequency. - and no, it can't be changed.

You can build a RGB/V laser with some fancy optics that combine 3 different beams to a 'white' beam, and modulating the 3 individual lasers gives rgb colour laser.

There are tunable lasers, which can have their output frequency adjusted over a broad range. Using three separate laser diodes will certainly give you nicely adjustable colors, but you do not get a new coherent beam at a different wavelength; you get an incoherent mixture of the three laser wavelengths, which your eye perceives as a color.

Agreed. the same underlying frequencies don't change.

Adjustable frequency lasers are WELL out of the price range of us lowly diy'ers.

Yep. I found turn-key systems from $4k to $10k through Google. However (and see my reply to Steve), you can build one at home!

Tunable lasers have existed for decades.

Amplitude modulation with sound (at kHz frequencies) does not do anything measurable to the laser frequency (at PHz frequencies). All it does is to affect the intensity envelope of the signal.