Fiber pumping for 532nm with 888nm interesting read.

[VDX]

... my idea was to try with 'only' max. 25Watts @808nm, so max. possible energy could be around 7-10Watts CW?

The pumping chamber is highly reflecting, so when pointing with an angle into one end of the rod a good part of the pumping light should be 'averaged' through the mirrors ... another should be 'zigzagged' inside the rod.

Another option could be filling the chamber with mercury (or Galinstan) for mirroring and passive cooling, so the mirroring will only take place inside the rod - and/or convex mirrors (reflecting 808nm/let through1064nm?) refocussing on the rod ends with a center hole for the resonator beam eventually could do another part of the 'averaging' and repeated pumping of the rod?

Viktor

[mixedgas]

Eric, Other then the airport and customs was amazingly efficient and friendly, I have not yet seen the place in daylight. Gas is 134.7 cents per Litre, and the weather is beautiful. The food, as is all food in Quebec, is wonderful. Company policy is to get a hotel within walking distance of the venue or work location. Thus I do not have a car here. I can walk down town this evening or tomorrow, and I'll let you know about the old city.

Sorry to hear about the late, lamented, pump diode. I am puzzled to why that has occurred. Please consider sending it to the factory for a post-mortem.

Steve

[planters]

Steve,

Do one of those self recorded travelogs where the hosts huge hand blocks one side of the camera's field of view. Anyway, ya I would like to hear if it really is fun, continental with good food and stuff to look at or rather a forced, fake tourist trap.

I put it under a microscope. The FAC is cooked. I took a IR video tour back down the beam line from the survivor and yep, dead centered on the damaged diode. After replacing the burnt diode I traced its beam and here the angle brought it about 4mm lateral to its twin. I then slightly tipped the murderer and now it too runs just lateral to the diode aperture.



VDX,

I think you will be successful if you use the diode as a diffuse monochromatic light source to side pump the rod as it was intended. The best conversion efficiency with these side pumped YAGs is about 10% to the green. The convenience of dumping large quantities of unfocused 808nm or if focused and collimated using the large cross section of the side of the rod compensates of this lower efficiency to produce high power. I don't know the doping % of your rod, but the absorption depth might be a problem if you end pump. For example, @ 0.5 A% Nd the 50% absorption depth will be a couple of mm (depending on the polarization). So, with a 1cm dia. rod and side pumping this works out pretty well. If end pumping, the vast majority of your absorption will occur in the first 1 cm. of the end. This set up might lase, but my guess is that the efficiency will be low. But who knows. If it isn't too much work you could try it.

[mixedgas]

Eric, after seeing daylight here, for a very interesting, spectacular, scenery, come. I'm Looking out at the harbor, buildings, bridges, ships, and mountains, etc. and wishing I had a car to go explore.

Sorry for the upside down pics. Shot from Floor 12 of my hotel. My Iphone's accelerometer trio is not working.

Update, not a tourist trap. Too expensive here to be touristy. Very dressy, very formal.
Well outside of my non-corporate travel budget, people are nice.

population ~500,000 in the region, Montreal is 145 miles away. Excellent Poutine, and French Canadians simply do not tolerate bad food.



Steve

[VDX]

@planters

... thanks! - will try with both methodes, but this can take a while ... actually busy with some more urgent projects ...

Viktor

[nuphotonix]

I have an omnilase with a fairly good sized tec cooling the the ndyag in a huge brass plug connected to it. Now this tec is separate from the tec that the c-mount 808nm diode is mounted. The Original 10 watt 808nm was DOA. the current pod on the pump circuit was cranked and under close inspection the gold wire that feeds the diode itself was vaporized. SOOOooooo looking for a big 808nm c-mount. I have a quad driver for it, just need to get busy and repair it. the brass mounting blocks are 2x2" cubes with the tec the same size. Very cool build. In searching for parts I saw the article on the side pumped 880nm NdYag with greater than 50% efficiency. Water cooled "pinch" block? Or is the vandate subject to ablation on the surface when exposed to the high temp laser at the point before it enters the crystal cavity at 1064nm??

[planters]

In searching for parts I saw the article on the side pumped 880nm NdYag with greater than 50% efficiency. Water cooled "pinch" block? Or is the vandate subject to ablation on the surface when exposed to the high temp laser at the point before it enters the crystal cavity at 1064nm??

Even for the fundamental this is unusually high. Could you link to the article? There should not be any problem with the vanadate being pumped through a side vs an end. The same requirements for AR coating and fracture limits should apply. The fracture limit is hard to predict because of variations in spot size, homogeneity, cooling and doping.

[nuphotonix]

https://spie.org/x15068.xml?highlight=x2404

[planters]

I know about this article. But, I think they are describing an end pumped system. For end pumping 50% is only fair and the state of the art is approx. 70%.