1064 or 808 for best green laser diode?

[zxn474l]

Would a 1064 diode be a better starting point to start with to build a green laser because it would only need one "crystal" to convert it to green laser light therfore loosing less power in the prosses of converting I.R. to visible green? If you know the answer please respond back!

 

[chipdouglas]

i have wondered this myself. (although i would never try to build one) but from what i have read hear it has to be the 808nm. hopefully pullbangdead will see this.

 

[ElektroFreak]

The real "how-and-why" is pretty complicated, but it's so difficult to directly double a diode that the very few commercial lasers that do all cost over $10,000 for less than 50mW. It's cheaper to just go with the standard three-step DPSS process: 808=>1064=>532..

One of the reasons that direct-doubled lasers are so difficult to build is that the beam specs of laser diodes are not that great. This effects efficiency in the doubling crystal. In the three-step process, these unfavorable beam qualities are rectified (mostly) inside the crystal that converts the 808nm light to 1064. The beam that emerges from this crystal will (if designed properly) be good enough for truly efficient doubling.

 

[GooeyGus]

If it were easier to use a 1064nm diode and directly double it, I think we would see it a lot more often. The bottom line is that the beam quality from a diode is SO far from perfect that it is very very very very very very very very hard to directly double them.

Start with 808 and do it the ol' fashioned way.

 

[pullbangdead]

Nailed it, beam specs from diodes generally suck compared to pumping a crystal. In addition to the shape of the beam, the output is much "cleaner" from optically pumping a crystal than an electrically-pumped diode. With a diode, it's difficult to nail down an exact wavelength (data sheets for 405nm, for instance, generally say 405nm +/- 5nm), and aren't a pure, single wavelength. But pumping a doped crystal, you get a very pure output, with very good, predictable, consistent wavelength. With optically pumping the crystal, the wavelength comes from an atomic transition that never changes, so it's always the same. But in a laser diode, the wavelength comes from band transitions that are engineered and controlled while making the diode, so it's pretty much impossible for every single transition to be the same

 

[Daedronus]

All that, and, most systems are doubled intra-cavity, or they are q-switched.

Both methods will get you very high pack powers in the NLO crystal.