ND YAG Breakdown Video

[Alaskan]

Thank you again kind sir, I was reading somewhere short nanosecond pulsed ND YAG's normally use flash tubes, that pumping with a diode won't produce short high peak power pulses unless a lot of extra machining is put into the thing and arranging the diodes in a 120 degree spaced pattern around the rod. (edit: I had forgotten you did indeed give me a diagram for that arrangement last year, just found it).

I am looking to produce from 3 to 12ns pulses at 2mJ or more for high peak power. Just don't want to get into trying to make a diode pumped YAG unit which requires positioning three bars at 120 degrees around the rod, too much for me to deal with, that and the power supply to run three 40W diode bars, yikes..... However, I did see a couple diode pumped YAG's on ebay, just wasn't sure how suitable they would be for short 3-12ns pulses.

http://www.ebay.com/itm/CEO-YAG-RB-64688-Diode-Pumped-Nd-YAG-Rod-Laser-Module-64688-/262093141354

I believe the above diode pumped YAG is normally used as an industrial unit, for CW output and not short pulsed nanosecond use, do you think such can be used with a Q-Switch to produce high peak power ns pulses? This unit has high hours, they run from 5000-10,000 hours and this is up above 8000 so may have been swapped out due to high hours, or problems. I never believe any ebay seller who puts up scrap items and then say fully functional, my guess is they might not know, just hope so, if it doesn't work then refund, in the mean time we are out the money and a waste of time.

If I could use the parts from one of my Lightwave 532nm DPSS "2.5 watt" eye laser YAG's which has a single 20W diode bar and use an EOM with it and get 1mJ or more out at 1064nm, I would consider that as a project if 3ns pulses could be produced, maybe as wide as 6ns.

The diagram you linked to last year:

Thanks.

 

[Alaskan]

Please excuse the double post, I'm both bumping and adding info. I found this interesting article showing the use of a IR LED pumped flat YAG, really cool:

https://www.osapublishing.org/Direc...4-11-12043.pdf?da=1&id=340997&seq=0&mobile=no

 

[diachi]

Please excuse the double post, I'm both bumping and adding info. I found this interesting article showing the use of a IR LED pumped flat YAG, really cool:

https://www.osapublishing.org/Direc...4-11-12043.pdf?da=1&id=340997&seq=0&mobile=no

Link won't work for me. How was the efficiency?

 

[Alaskan]

I was able to download the document, normally they require payment. Don't know how I was able to get it for free. Here is a cut and paste:

Efficient 750-nm LED-pumped Nd:YAG laser

Kuan-Yan Huang, Cheng-Kuo Su, Meng-Wei Lin, Yu-Chung Chiu, and Yen-Chieh Huang*
HOPE Laboratory, Institute of Photonics Technologies/Department of Electrical Engineering, National Tsing Hua
University, Hsinchu 30013, Taiwan

*ychuang@ee.nthu.edu.tw

Abstract: We report an Nd:YAG laser pumped by light emission diodes (LEDs) at 750 nm. With 1% output coupling from a linear cavity containing a 2-cm long Nd:YAG crystal, the laser generated 37.5 μJ pulse energy at 1064 nm with M2 = 1.1 when pumped by 2.73-mJ LED energy in a 1-ms pulse at a 10 Hz rate. The measured optical and slope efficiencies for this linear-cavity laser are 1.36, and 9%, respectively. With 1 and 5% output couplings from a Z-cavity containing the same laser crystal, the lasers generated 346 and 288 μJ pulse energy with an optical efficiency of 3.4 and 2.8% and slope efficiency of 6.6 and 14%, respectively, for the same 1-ms pump pulse repeating at a 10 Hz rate. At the highest output from the Z- cavity, the measured M2 for the beam is 3.6.

 

[diachi]

I was able to download the document, normally they require payment. Don't know how I was able to get it for free. Here is a cut and paste:

Efficient 750-nm LED-pumped Nd:YAG laser

Kuan-Yan Huang, Cheng-Kuo Su, Meng-Wei Lin, Yu-Chung Chiu, and Yen-Chieh Huang*
HOPE Laboratory, Institute of Photonics Technologies/Department of Electrical Engineering, National Tsing Hua
University, Hsinchu 30013, Taiwan

*ychuang@ee.nthu.edu.tw

Abstract: We report an Nd:YAG laser pumped by light emission diodes (LEDs) at 750 nm. With 1% output coupling from a linear cavity containing a 2-cm long Nd:YAG crystal, the laser generated 37.5 μJ pulse energy at 1064 nm with M2 = 1.1 when pumped by 2.73-mJ LED energy in a 1-ms pulse at a 10 Hz rate. The measured optical and slope efficiencies for this linear-cavity laser are 1.36, and 9%, respectively. With 1 and 5% output couplings from a Z-cavity containing the same laser crystal, the lasers generated 346 and 288 μJ pulse energy with an optical efficiency of 3.4 and 2.8% and slope efficiency of 6.6 and 14%, respectively, for the same 1-ms pump pulse repeating at a 10 Hz rate. At the highest output from the Z- cavity, the measured M2 for the beam is 3.6.

Thanks for that! A little better than I expected, but still not nearly as good as LD pumped - a point I've made before- it'll work of course, but just not nearly as efficiently. Any mention of electrical power consumption?

Bad M2 factor is not surprising either, cavity design could have improved that but would have sacrificed efficiency.

Any chance you could send me the paper? I'd be interested in reading more.

 

[Alaskan]

PM'd a link for you to download it from a site I have hosting a lot of my stuff. I would post the link here, but I might get in trouble with them if they tracked me down for giving away their stuff for free.

 

[diachi]

PM'd a link for you to download it from a site I have hosting a lot of my stuff. I would post the link here, but I might get in trouble with them if they tracked me down for giving away their stuff for free.

Yep, that's the best way to do it. Thanks!

Edit: For anyone curious about the difference in efficiency, with LD pumping upwards of 50% optical efficiency can be achieved.

 

[Accutronitis]

Oh ? when you said "breakdown" I thought it blew up or had a meltdown....... lol

 

[Seoul_lasers]

Wow, very cool find!

Nice information. An LED pumped laser.

As Spock would have said...