Weird POV effect with 589nm.

CurtisOliver said:

What specification does your 15W C-Mount have. What is the spectral tolerance? I have a Coherent FAP-800 50W that is rated +/- 3nm. This was used in their Coherent Verdi systems and would of been likely to of produced 10-15W of 532nm. If this was +/- 3nm, then I gather your 15W would be acceptable. I can only imagine a 20-30% increase in 1064, for the phase matched 4W. If we presume that 50% of the 808 is converted to 1064, and 60% is converted to 532 then the figures will probably be like:
808 +/- 3nm(15W) --> 1064 (7.5W) --> 532 (4.5W) This is quite an efficient system you would probably expect to have a system efficiency of around 20-30% (3-4.5W)
808.4 (4W) --> 1064 (2.8W) --> 532 (1.68W) The 1064 conversion was 70% in this model.

This is pure speculation. I could look at the graph and try to approximate a true increase in absorption, but it wouldn't be necessary.

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Wow, cool info. This 15 watt diode did not come out of anything I know of, is just another one I have. It is new old stock, I have three of them.

Here are the spec's for a non-FAC version of the same diode:

Specifications:

808nm 15W C-Mount Laser Diode

CW output power (W): 15.0

Peak wavelength (nm): 808 +/-5nm

Spectral width (nm): ≤4

Threshold current (A): ≤2.4

Operating current (A): ≤16.0

Slope efficiency (W/A): ≥1.1

Beam divergence θ∥×θ⊥ (deg.): 8/30

Wavelength temperature coefficient (nm/℃): 0.3

Emitting area (μm): 400×1

Thanks for the specs.
With a spectral width of 4nm and a tolerance of +/- 5nm it will be close. 803-813nm would look like this on the absorption graph attached. It will be close, but as long as your bandwidth falls near the central wavelength specified, you should be fine.

Great, I will have to set it up on a optical breadboard and see what I can do without a TEC, would be awesome to make a portable unit out of such a high power 532nm but sadly, seems it may become illegal!

Shame about the legality side of things, but good luck! If it all goes well, and is relatively simple. I may have to get advice from you about doing it myself when I get some money. I would be interesting mainly in the ease of the setup, and the output conversion efficiency you achieve. Imagine me pumping with 50W of 808.

I have like a dozen 40 watt FAP800's, but they are so large so was thinking the 15 watt C-Mount would be a better candidate, but maybe not.. I have about a half dozen to do projects on the back burner, don't know when I will get to them working over seas. Because of this I have the help of CDBEAM777 for one of them which is nearly finished now and a second one for him to start on early next year.

I agree the FAP-800's are rather large, and require a very specific power supply as I have found out. Also as I have a FAP-I (Integrated), The TEC connector is specialist. In order to cool it I would have a to get a separate TEC and driver and cool it that way. It means mounting the TEC on the bottom of the laser. Not ideal.

Working abroad does kind of complicate things. Just become the master leader of LPF, and have minions build your projects for you.
Not enough time or money, for me to complete most projects I dream up.

I know what those FAP-I units are, I have some of those too, been buying IR parts for four years now and have not done enough with them. I have powered my FAP800's with a 0-7.5 VDC lab power supply capable of up to 60 amps (but CC limited to 50 amps) as well as a simple direct connection to a Cyclone 2 volt 25 AH lead acid cell and did not have an over current problem running a 40 W FAP for 20 minutes that way, the battery draining down in that period of time so far that the power output was halved in that time. I know, we are supposed to use drivers, but I tried this with my bench power supply first with the CC control turned all the way up to 60 amps and with the large heat sink I was using, the current did creep up after 10 minutes, but when using a single 25AH 2 V lead acid cell, the voltage starts to drop so counter acts an over current problem. I should say I would not expect this to be situation if I wasn't using a large heat sink, without that, I would expect the same over current problem to start creeping up.

Here is a link to the battery I used:

HAWKER ENERGY,0820-0004,BATTERY, CYCLON, 2V, 25AH | eBay

I ordered mine from a local battery shop in Anchorage, Alaska because the price was much better, I think I paid 65 dollars for it and they didn't charge me shipping.

I never thought of running it off a battery before. I did once find someone selling a 2V 60A power supply, but it wasn't adjustable. I also brought a 0-5V 0-60A variable supply but at 2.2V it only ran at ~18A. What lab supply do you have?

Here is a thread about it: http://laserpointerforums.com/f49/c...ckage-beam-shot-movie-added-thread-95501.html

I made a little video showing it burn card board: http://s853.photobucket.com/user/LaserProject/media/IMG_4378.mp4.html?sort=3&o=0

I can't get this movie to run on my notebook here, don't know if the link will work for you. Re-reading the thread, it appears my battery ran down to produce half output power after 10-15 minutes, not the 20 I remembered. I am trying to remember the power supply model number, I seem to remember it was made by Xantec, but that is all I can tell you right now. If you can get the video to work, I may have mentioned the manufacture name, I might be wrong about remembering the name. Not old age, I have always been this way to where if I don't use it, I loose it.

Edit: Use this link for the video: http://vid853.photobucket.com/albums/ab95/LaserProject/IMG_4378.mp4 but I didn't say thing, the power supply is on the desk under the Molectron LPM.

Thanks for sharing. I managed to locate a 0-7.5V 0-140A Power Supply based on the video.
Nice work, it is amazing and scary how quickly it burns. I have only ever managed to get mine running at threshold.
Here is the link.
Xantrex XFR7.5-140 Variable DC Power Supply 0-7.5V 0-140A GEN8-180-IS510 | eBay

Aha, that is it, I also have a 0-20 VDC 60 amp version of the same power supply, I forgot the 0-7.5 VDC would do more current.

Yes, I saw in the image that it delivered 100A at 1.1V. This is perfect. The one I have at home wouldn't allow any more current without increasing the voltage. Thank you for your help. I have saved the link so I can refer to it in the future. Just need some crystals capable of running at 30W at the very least and then I will have a high powered 532 dpss.

Alaskan, easiest way to match the LD to the YAG/YVO4 absorption is to have an LD that comes close and then temperature tune it. Needs for KTP vary depending on the setup and type of KTP. Flux grown KTP likes things fairly cool, around room temperature (25C). Hydrothermal KTP likes temperatures in excess of 40C and as such usually requires a heater.

Power fluctuations we see in DPSS pointers have several causes, shifts in pump wavelength due to temperature changes, distortion of the cavity due to temperature changes and reduced efficiency in the KTP due to temperature changes. Those are the big ones at least.

Think Curtis already answered all those but figured I'd weigh in anyway.

I guess the only way to know the difference between a flux grown crystal and a hydrothermal is by testing them to see if they like it close to room temperature, or quite warm, if you are finding them on eBay and the seller doesn't know?

Thanks for chiming in, sometimes things said another way can be very helpful.

I guess the only way to know the difference between a flux grown crystal and a hydrothermal is by testing them to see if they like it close to room temperature, or quite warm, if you are finding them on eBay and the seller doesn't know?

Thanks for chiming in, sometimes things said another way can be very helpful.

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The other way of knowing is the phase angles. The difference between hydrothermal and flux grown KTP is subtle.

CurtisOliver said:

The other way of knowing is the phase angles. The difference between hydrothermal and flux grown KTP is subtle.

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This exactly. If you don't know anything about your crystal you'll need to experiment with temperatures and angles to see what's most efficient. If you know all of the specs for your crystal then you have a good starting point. Something else that adds more complexity to DPSS, adjustable mounts for non-linear crystals - being able to adjust horizontal/vertical/rotational makes life easier if you're trying to achieve best efficiency - which becomes more of a necessity with the rarer wavelengths.

I'll post this again in case anyone hasn't seen it - It's a DIY 532nm DPSS with a Z-Fold cavity, built by Planters who's on here and PL:



Check the rest of that channel out too, lots of good videos!