565nm From LaserLandAustralia

[Mosc007]

The laser modules I sell are different to the ones that the Chinese are selling. Even though mine is more expensive being 2-5-3x higher it’s the total cost of the module including shipping. the modules themselves have a higher output powers 1.5-2x. The shipping prices may be high but its the fee that I get charge with to send by DHL.

I can confirm it looks like yours are not the same as the ones from Alibaba.

The first batch of 565's measured 30mw from you and 19mw from Alibaba.

EDIT: I forgot to mention from the limited data available the beam profile on yours is vastly superior. My 565nm from you has an almost perfect circular beam. One shown from Alibaba had a horrid shaped beam.


When my 575 arrives I will see what it meters out. I expect probably more than double the ones on Alibaba.

It seems like it's ok to post links to sellers but the sellers themselves can not advertise on here.

 

[LSRFAQ]

For the guys who keep pounding me with PMs on how to shift the wavelength.

Preliminary explanation
It is very coating dependent and less pump diode dependent. To change colors you need to change what is reflected in BOTH the IR and the Visible. You also need to kill the competing lines by transmitting them out of the laser cavity. SO the add a mirror trick needs a mirror coated for both the primary and frequency doubled wavelengths, or it will not work. The optics will be coated to kill competing colors and control lasing bandwidth. This is NOT single pass frequency doubling, the SHG wavelength probably needs a controlled S2 T of say 0.5 to 3 %.

The green hop observed by one owner was temperature dependent for a reason, the gain in the IR band that creates the green temporary exceeded the gain in the IR band that produces yellow during warmup.

There is a holdup on my getting the test lasers until my friend gets back from vacation. They are in his mailbox.

When I get my grubby little hands on the in-expensive one I will run the experiments most of you do not have the tools or optics for..

The Physics of this one are a bit deeper then anything 95% of LPFers have ever dealt with. Most of you have never dealt with this kind of non-linear optics. The simplified explanations of laser physics you have been taught just suffered from suicide by fenestration.

Your cameras will not photograph the Yellow correctly because the dichros coated on the CCD to separate RGB to each pixel triad (or quad) deliberately have an overlap at this wavelength between the red and green channels. If you have a BAYER format CCD (RGGB) it will be even WORSE. This goes back to the chrominance definitions of PAL and NTSC color, and with the exception of a few very good lab and cinema cameras, your screwed.


See attached...

New problem... For Aviators, red and green are easy to deal with.
You make cheap rainbow pointers, pointers will be limited to red to make the pilots happy. BE VERY CAREFUL WHAT YOU WISH FOR. This is WHY your not seeing handhelds.. The makers know that if they start making pointers out of these, well... Put on some R.E.M playing "Its the End of the World" Because BOTH the Chinese and American governments will have something to say.
This yellow wavelength is right at the Photopic (Daylight) vision sensitivity peak and can be very annoying if misused.


ALSO, the 575 Wavelength is at the peak of Blood Hemoglobin adsorption in the eye, and is thus used as a Eye Surgery and Dermatological laser. You get a hot beam of 575 in the eye and it is far more (at least 2X) likely to do blood vessel damage then 532.. BE CAREFUL!

 

[Mosc007]

Thanks LSRFAQ,

Some very useful information.


If you can measure the pump frequency for us that will explain a lot.


My money is still on a 1130-1150nm IR Diode. With direct doubling. How the direct doubling works is not all that important to most of us. Basic operation will do. But the image you posted is interesting.

Still interested if its new coatings though. Or does poorly manufactured 1064/532 coatings work at 1150/575 just with lower effiency. This laser is a much lower effiency than 532nm DPSS.

The price of this laser tells me its not a new crystal. Prob cheap chinese KTP.

 

[kecked]

It’s all my fault. The lasers came while I was away. Have to wait till Saturday to come and play. Darn my photon just ran away.

What happens when a sub atomic particle exhausts itself in the gym.... waveform collapse.

 

[ZRaffleticket]

We'd be saying the same thing about the sharp 490s if we hadn't had all the test batches and buildup we got lucky to get our hands on. I'll say it, it was all luck. I wouldn't count out something new and different.

To me, this looks like another player in the laser industry is pushing cheaper processes for medical/bioscience lasers.

 

[kecked]

I’d like to see a 600nm orange next. Not too far away from 575. Anyone try cryocooling one of these yet.

 

[Sta]

How would you get the module out of one of these units? I’m gonna try to extract it from my 565.

 

[steve001]

Thanks LSRFAQ,

Some very useful information.


If you can measure the pump frequency for us that will explain a lot.


My money is still on a 1130-1150nm IR Diode. With direct doubling. How the direct doubling works is not all that important to most of us. Basic operation will do. But the image you posted is interesting.

Still interested if its new coatings though. Or does poorly manufactured 1064/532 coatings work at 1150/575 just with lower effiency. This laser is a much lower effiency than 532nm DPSS.

The price of this laser tells me its not a new crystal. Prob cheap chinese KTP.

Did you see the links I posted today? I think they explain what's going on.

 

[diachi]

My money is still on a 1130-1150nm IR Diode. With direct doubling.

Going by what Steve (LSRFAQ) is saying it's not direct doubling at all, but a self doubling gain medium (think Nd:YAG that acts as a gain xtal and a frequency doubler all in one). Not saying it's Nd:YAG, but think of it that way.

Going to go with that explanation for now and wait for more detail. I imagine it's something Steve has seen/read about/experimented with before. :beer:

 

[ZRaffleticket]

How would you get the module out of one of these units? I’m gonna try to extract it from my 565.

On the Aussie units, unscrew the fan, then on the bottom there are two set screws you can loosen with an allen key. Then the module slides out the back where the fan was.

Yours will probably come apart very similarly

 

[Encap]

Did you see the links I posted today? I think they explain what's going on.

Going by what Steve (LSRFAQ) is saying it's not direct doubling at all, but a self doubling gain medium (think Nd:YAG that acts as a gain xtal and a frequency doubler all in one). Not saying it's Nd:YAG, but think of it that way.

Going to go with that explanation for now and wait for more detail. I imagine it's something Steve has seen/read about/experimented with before. :beer:

Whatever the technology used is it has be dirt cheap if the entire unit module, housing, driver w housing, & lens, one piece at a time, essentially sold retail to anyone for $30 and in quantity for $24 or perhaps even less by negotiation.
How much can it cost to manufacture the laser module by itself as a component part $3 to $6 range at the outside maybe?

I assume it is not the true yellow CNI makes and sells as shown in this thread about a GLP DPSS 5mW rated, 577nm pointer purchased by Dr.Laser in August 2017 from CNI and cost approx. $2300 but maybe...
Dr.Laser speculated it might be a "Dy3+ doped crystal pumped by UV/Blue diode, different sources report that Dy doped crystals emit yellow lines at 575-580nm depending on the crystal composition when excited by UV/Blue light. The center of excitation bands are 325, 352, 366, 389, 427, 453 and 474 nm." or perhaps a more complicated DPSS process.

Parenthetically, his photos very good and it shows as quite yellow even though camera is making it more green than it is.
See:

CNI's professional lab versions MGL-F-577 run $3800 for 10mW, $4000 for 20mW, and $4500 for 30mW retail and up from there to $9600 for 500mW and about the 1/2 that for 561nm see: https://www.ultralasers.com/lasers-series.php?cat=211 .

Will be interesting to find out what the technology used in the $30 product really is.

 

[LSRFAQ]

Did you see the links I posted today? I think they explain what's going on.

Before I sold it to my friend, I had a 55 mW unit on a spectrometer with 0.5 nm resolution. The lasing medium shifted center wavelength outside the classic three 1120 nm yag lines by 5 nm during warmup. It also had a lasing band about 3 nm wide centered on its moving center frequency. That clearly rules out the ND 4F3/2 → 3I11/2 manifold which is the first thing I looked for, expecting the low cost laser to hop between the three discrete lines. It doesn't, it smoothly slides across a band permitted by the cavity optics.

The bandwidth of the 11xx YAG lines are no more then 2.2 nanometers, as I have a thermally tunable ND:YAG 561 in a machine at work and checked it closely by pushing the tuning.

So while I thought that at first, it would be 4F3/2 → 3I11/2. I took a good long look at the materials available. I know what it is, I spent most of the night last night doing a literature search and I have the paper stored on my laptop.

I'm just going to confirm it before I link it. I live behind an academic firewall, I have access to some search tools that Google doesn't wish to pay for. It took a couple hours after work to find the likely candidate.

If you look at the posted pictures of inside one of these it is a thin microchip laser, of a nearly transparent medium, with a coated microchip and one external mirror. It does NOT show evidence of a second crystal in the cavity.

The fact that one video shows a higher powered module hopping from a 561 green while cold to a yellow takes it right out of the historic 4F3/2 → 3I11/2 concept. ND:YAG 1123 has 1/9th the gain of 1064. It tends to need thermal stabilization to stay lasing. The cavity has to be designed to suppress 1064 to prevent it robbing power from or killing 11xx lasing. No way an Nd:YAG would flash green and switch to yellow with that design constraint.

I have a bunch of 11xx nm optics sets for Yellow Nd:YAG and they all specify a minimum of 60% transmission at 1064 on all three optics in the set to ensure it can't spontaneously lase at 1064 while trying to generate 1122. They also coat the rods to slightly reflect 1064 while AR at 1122 to prevent any 1064 lasing.


If its what I think it is, the pump diode has to have a wavelength somewhat shorter then IR wavelength being generated to comply with Stokes law, but close enough to be just above the upper manifold. Probably within 100 nm, so the pump will probably be in the 900-1100 nm range. Right where silicon in a cheap CCD spectrometer will not see it or barely see it.


This is a complex beast that has been known for a few years, but is only now hitting the market. Its not known for its ability to be scaled to high power in a thin disk or sheet similar to what is in the photo. Overdriving the low cost ones will possibly result in a cracked crystal.

Its not Neodymium in all likelihood, at all. If a Prof here agrees it is a fun learning project for one of his laser sciences students, I will probably pump it with a tunable Ti:Saph in a few weeks. It is the summer academic holiday around here for the next two weeks, so just waltzing into a borrowed lab Sunday to mooch a few minutes time on a Chameleon is not going to happen, everyone is away.

I think I know, but as stated previously, I'm no hurry to be wrong. MY hat is off to the team that developed this medium. If your having a laugh reading this thread, please enjoy.

Edit: Left out the word NOT by mistake.

Steve

 

[paul1598419]

I bought mine from Shenzhen OPTlaser Technologies. Their email address is: fb@optlaser.com. The laser cost me $30.00 and shipping was $35.00 by DHL which got my laser to me in less than four days. I have to upload my photos and put them on imgur. Then I can post them.

 

[BowtieGuy]

Thanks for the info., Paul. :yh:

 

[paul1598419]

My pleasure, Jeff. I hope others can get one or more of these amazing lasers for less than dinner out would cost.

 

[Mosc007]

Lazer2107,


It seems you have sent mine with the cheapest possible postage service you could find.

Delivery to the US was quicker than from Perth to Sydney.

I still don't have it and Aust Post says maybe next week.

The first one I bought from you was 3 days. This will be more than 9 days by the look of it.

I also don't like expensive items sent without needing a signature.