It’s my understanding that most of the high power 532nm green lasers are actually 808nm diodes, with the 808nm beam being upconverted by Nd:YVO4 to 1064nm, then halved to 532nm by a KTP crystal. I have read that some of the high power units only measure that way because some of the IR light leaks out and contributes to the overall power reading, while the green beam isn’t actually all that powerful. Most customers don’t want that situation, but I do. I’m wondering if I could order a 532nm laser module that has less AR coatings and no IR filter. I’m hoping that would emit all 3 wavelengths (808-1064-532nm), which I could then select the needed wavelength using external filters.
I only need 1 for a prototype right now, but would need many more once I’ve perfected my product.
If modifying a green laser isn’t feasible, there are some other options that may work for my application that I’d like to get your opinion on whether or not they are feasible or if you sell the necessary components:
- Buy an Nd:YVO4 window that is not bonded to a KTP crystal, and place it in front a stock 808nm module. I have seen some Nd:YVO4 for sale but it’s always already bonded to KTP, and I’m not sure if it can be un-bonded.
- Buy a bonded Nd:YVO4/KTP crystal, use it in front of an 808nm module, but without an IR filter so its putting out a mix of the 3 wavelengths, then use a switchable band pass filter assembly to select between wavelengths.
- Use multiple different laser modules including 1064nm direct diode module, which will triple the size and cost of my product
- Laser headlight type approach, multiple visual and IR phosphors lased by a common laser module. Output wavelength could be selected by a rotating phosphor screen assembly similar to a laser projector’s rotating filter, or switchable external band pass filters.