Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



BLUE VISIBLE DIODE PUMPED CW DYE LASER

LSRFAQ

Well-known member
Joined
May 8, 2009
Messages
1,075
Points
83
Years ago it was done in the IR with very high gain dyes and very tiny outputs and far red or IR diode pumping.

For years I've been explaining why this is very difficult in the visible, needing a flowing jet, 200 nanosecond transfer time, quenching, spot size from the diode, triplet state issues. Ten years ago I told people it was simply impossible in the visible, and it was.

OK, Its been done, but in a way that pretty much closes the door to even your above average hobbyist because of the cost of duplicating the hardware.
Still in the research institution / large corporation realm, but it has been done.

The first author to do it used high power green LDs and pulsed them at 200 Nanoseconds, waited a half a second for the diode to cool, and pulsed them again.
A 200 nanosecond or less high current LD driver with the proper current clamping and overshoot diode protection systems is not in the realm of all but the most skilled and ardent hobbyists. (READ YOU NEED TO BUY ONE< AND THEY ARE NOT CHEAP) These folks had the funding to build a really customized optics train.

At the focal spot there was 0.5 Kw per square cm, and output was ~0.3 micro Joule with near zero output coupling. 2Hz at 0.3 uJ means yes, I have a laser, but not a really useable one for most lab purposes.

A second group has succeeded in CW operation using a 445 nm pump.

The system losses are high, and a modified commercial ring dye laser was used. The pump beam spot size had to be reduced, lots of mirrors changed, and the output coupler transmission reduced.

Two dyes, one does the energy transfer to the other dye. This is barely efficient enough... But it will reduce the T state quenching problem.
A Really highly modified unidirectional ring dye laser based on a fluid jet was used. A Coherent 699 series. No longer in production and the facility just happened to have a pile of different blue-green optics sets for it. One rare set of optics, as the laser was rarely ordered for the blue-green output region.

The poor beam quality of a 4 watt 445 Diode made this extremely difficult, and considerable time and modification of the dye laser was involved. If there was a 4 watt 445 nm blue diode with perfect TEM00 Transverse mode, this would have been an easy process. However such a thing does not exist. Nor does throwing an array of 445 diodes into the laser system solve the problem, as mode matching is critical at the focal spot of the dye jet. "Morrrr Power!" is OUT as a solution, the spot size and shape is critical. So basically throwing a high power blue array at the problem does not help you much, as your only using a small fraction of the power in the beam.

This was done with a highly modified 20,000$ (1980s Dollars) laser system with special optics. While 699 do show up on Ebay, they will generally have optics for yellow-orange operation for Rhodamine and will not be applicable to this process. As the special mirrors have not been produced in years... Well... Cloning this research would be REALLY Expensive.

The key words here are "Energy Transfer" as a suitable directly pumped dye and optics set for the same are not available.

Don't get your hopes up just yet for a home made table top CW dye laser, unless you are financially wealthy.

So if you own something like a 4-5 Watt Verdi with a TIGHT TEMOO SINGLE MODE BEAM and a 599 Ring laser, you could have tabletop dye. I helped a fellow do that, but he too, needed to change the OC on the dye laser. I had the rare OC he needed. He got about 300 uW and learned the hard way about how 30-60 psi dye jets are not good for the kitchen carpet.

Steve


REFS:

Highly efficient tunable pulsed dye laser longitudinally pumped by green diodes
Applied Physics B, 2018, Volume 124, Number 9, Page 1
O. Burdukova, V. Petukhov, M. Semenov

Tunable single-mode cw energy-transfer dye laser directly optically pumped by a diode laser.

By: Stefańska, Danuta; Suski, Marcin; Zygmunt, Anna; Stachera, Justyna; Furmann, Bogusław. Optics & Laser Technology. Dec2019, Vol. 120, pN.PAG-N.PAG. 1p. DOI: 10.1016/j.optlastec.2019.105673. , Database: Computers & Applied Sciences Complete
 
Last edited:



LSRFAQ

Well-known member
Joined
May 8, 2009
Messages
1,075
Points
83
My office floor tiles have a few pink sections. Stray R6G powder is like the Spanish Inquisition, No One Expects it, and really stains everything. :) Bleach, Alcohols, Acetone, Xylene, nothing will fully de-color the tiles, and the more you scrub with chems, the more it changes to pink from orange.

Steve
 

diachi

Well-known member
Joined
Feb 22, 2008
Messages
9,745
Points
113
My office floor tiles have a few pink sections. Stray R6G powder is like the Spanish Inquisition, No One Expects it, and really stains everything. :) Bleach, Alcohols, Acetone, Xylene, nothing will fully de-color the tiles, and the more you scrub with chems, the more it changes to pink from orange.

Steve
My kitchen counters can attest to this. Even the tiniest spill leaves a bright pink and rather permanent stain. Thankfully only have a couple tiny spots. I make a point of working in a large glass tray to minimize mess.
 




Top