Holographyforum.org / holowiki.org

A good way to adjust the heater is by using a “buck board” or step down transformer, 5vdc goes in on one side
1.5 vdc comes out the other side, connect to heater, it’s only a resistance heater coil so no worries about +or-.
I’ve ordered 20 pieces from China ....... at a dollar
Each !

Here’s a pdf link to this tiny OPS Laser Kevin on FB
Was kind Enough to share the data sheets he found

http://optoengine.com/images/Documents/ ... DNtHSfnOoM

A little more light on the subject:
https://www.researchgate.net/publicatio ... our_pocket

Good show John, good read too!

It looks like it is an 808 nm pumping a OPS to 1060 nm then frequency doubling through a PPLN to 630 nm.

There is an article about predecessor of this laser, dealing with effect of various intracavity elements, namely doubling crystals and filters.
https://www.researchgate.net/publicatio ... disk_laser

The reason, why this laser is usable for holography is presence of birefringent filter, in projector application intendet to reduce power fluctuation. This BRF force it to SLM and reduce both power noise and linewidth greatly.

I have two second generation PL530 prototypes Dave built tested and ready to make holograms. Plug and lase, no building, soldering, tuning required. $400 for 40 mW, $500 for 50 mW with free shipping to the USA. Not everyone is equip to build and tune their own. Ready to make holograms 30 seconds after turn on. No kidding. Phil

IF the doubler has a resistance heater wouldn't a constant current be better then a constant voltage driver? The heater adjustment is the critical thing. Phil

Heater temperature is really critical, affecting output power and mode structure strongly. Any fluctuation also dramatically reduces effective coherence lenght, even if SLM is maintained.
The doubler heater is actually PTC (positive thermal coeficient thermistor), the PL530 is really similar to Sapphire. This means that constant current drive is the worst case, due to any fluctuation of current is multiplied by resistance change of PTC. Moreover, case temperature fluctuations are also amplyfied due to PTC. Altough it works reasonably well for me, particullary thanks to my very stable current and TEC driver. Constant voltage would be much better choice, fluctuation of voltage and case temperature will be attenuated by PTC effect. In the datasheet above, there is mentioned the constant resistance drive. I'm trying to build it, because it promising elimination of need for TEC, the doubler temperature will be independent on case temperature!

Finaly, I have designed and tested constant resistance PPLN heater driver: it is amazing! Absolute stability over wide range of diode current, without any movement of the optical frequency peak on FPSI screen. Only small dependency of the frequency at temperature. At 18C and 420mA I get 85mW pure SLM and rock stability.