Recent content by brianpe

Nope. What you're talking about is second harmonic generation. Two photons of the same wavelength come in, and through some fancy quantum mechanics out pops one photon that's half the wavelength. There are so many variables getting any kind of efficiency out of this that you are much better...

I have a Coherent FAP housed in the full module with monitoring and TEC. The FAP is in pretty bad shape (emits 3W @ 30A). I have another FAP I want to swap in and reuse the TEC. I've removed most of the module but the FAP is bonded to the heat spreader with a thin sheet of indium foil and I...

Selecting parts is really hard -- there are so many. But unless you have specific needs (high power, fast switching, low noise) there are some standard parts you can start with. For op-amps, Dave on the EEVBlog has a good video on what he calls "jelly bean op-amps", which are generic, common...

I designed a control board that can do 53 amps 4v into two channels each for a dual end-pumped z-fold cavity. It's switch mode based on the MAX20096. It uses some pretty beefy MOSFETS and inductors and has a switching speed of 1Mhz so it's pretty clean. Can run on a 2s LiPo pack but it's...

I did try inserting a 1/2 wave plate and rotating that -- there was a small (5%) improvement depending on orientation. I haven't tried rotating the whole fiber. These FAPs have random polarization so they will lose some efficiency here for sure. The Verdi's use them into vanadate too so I am...

If you have a power meter you can test how well your current goggles work: defocus the laser and shine a somewhat broad beam through a pair of goggles and measure what comes through on your power meter. If that transmitted power is <= class 1, your current goggles are fine. Just be sure to wear...

Ok, so for the last couple of years I've been working on building a portable DPSS laser. It's a Z-fold cavity design powered by two 40W FAP modules. All electronics are battery operated by an integrated LiPo pack. At full tilt there is enough battery to run it for about 30 minutes. It's portable...

A DPSS laser I built from scratch. It's huge, heavy, and I'm glad it's done. Only it's not done really, because there are a lot of optics problems I need to fix. Is something like this ever really done though?

The main circuit boards, fans and pump FAP lasers. The top board is a two channel laser diode controller that can do 50A / channel. The bottom board is a four channel TEC controller. Each are controlled by a host microcontroller.

The resonator and power sections. The laser is running here at low power. the baffle between the laser resonator and power sections has a foam sealing around it so when the cover is on the resonator stays dust free.

An infrared image of the resonator in operation.

The output end of the laser. The window has a filter to filter all light longer than about 700nm to ensure no stray infrared gets out.

Ok, it's long -- about 33 inches. The center handle is placed at the balance point so you can still operate the controls with your other hand.

The control panel uses a white OLED screen so it is visible with goggles on. The display shows drive current, measured power output and temperatures of diodes, vanadate, and KTP. Indicator light is green when ready.

A beam shot across the garage. Running at about .5W.