473nm Blue Modules

GooeyGus said:

Well, in LBO's defense, there are two types.

Type one is much easier to work with and can phase match at room temperature and is not *quite* as picky when it comes to crystal temps

Type two requires the crystal to be heated to within a couple degrees for doubling to occur. This method is much more efficient but much more difficult to work with.

Most 473nm lasers any of us have played with will be type one,

(I may have gotten the one and two backwards, but you get the idea)

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To expand on that, there are two types of doubling you do with LBO, critical and noncritical phase matching.

Critical phase matching is what it used in most low cost lasers, it is easier to do, and does not require high temperature or high stability. The problem is that it is not as efficient as noncritical phase matching.

Noncritical phase matching is much more efficient however it has some drawbacks. First off, for LBO, you need to heat the crystal to around 150C depending on the angle of the cut. The temperature is also very critical. A change by as much as half a degree, can change the efficiency greatly.

Depending on the laser you are looking at, it will either use noncritical or critical phase matching, it is pretty easy to detect too, just look for the large heater. Additionally, some lasers using it are doing so because the efficiency of the IR to Green conversion.

In most cavities, the main limit on power is overheating on the lasing medium, after that, it is the circulating power, which in many cases can reach hundreds of kilowatts or even megawatts.

In a simple linear cavity using a doubler, you would have two HR mirrors for the IR, the "Output coupler" is simply AR coated for green. This means that the amount of IR the doubler converts, is the amount of light that escaped the cavity. If you remove the doubler the cavity circulating power will increase and is only limited by the losses from the HR mirrors and AR coatings on the lasing medium, in other words, it is likley there will be damage caused.

wait wait, but there are thin pen pointers in 473 and 594nm already? they surely cant be 20mm diameter?
ah, if i had won the CNI competition, i would have extracted the yellow module from the pen and built it in a flashlighthost, matched to my red, green, BR and soon 635nm.. perhaps better that way, that i didnt win ;-)

manuel

Krutz said:

wait wait, but there are thin pen pointers in 473 and 594nm already? they surely cant be 20mm diameter?
ah, if i had won the CNI competition, i would have extracted the yellow module from the pen and built it in a flashlighthost, matched to my red, green, BR and soon 635nm.. perhaps better that way, that i didnt win ;-)

manuel

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I don't know the size of the yellow pointer, I will confirm it once it arrives.

The CNI Aquarius blue pointer that I got through Glenn is 16.5mm O.D. and it takes a CR2 battery.

I believe their yellow pointer takes 2 X AAA batteries, so I would guess that it is 'slimmer' than the blue pointer...

thanks for measuring!

manuel

2007Revolution said:

The yellow is exaclty the same as the standard CNI black and gold green pen except it is 2mm longer for some weird reason.

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Could be the module that is longer since it has even more crystals inside. The 2*AAA's stick out of it until you screw on the cap.

The number of crystals in a yellow is the same as a green or blue, just different coatings and doubling (or in yellow's case, summing) mediums :beer:

Yellow lasers lase on two different wavelengths of IR at the same time (solid state multiline laser anyone?). Then these two wavelengths go into a nonlinear optic and get frequency summed into 593.5

true! ..bur maybe there are discrete crystals in those yellow ones? then you could say there are more crystals inside, two, instead of one combined!

would like to see how those are build up inside.. both blue and yellow. the theory is clear, but how do they do it practically, as efficient, tiny, cheap, stable and easy as possible?

manuel

GooeyGus said:

The number of crystals in a yellow is the same as a green or blue, just different coatings and doubling (or in yellow's case, summing) mediums :beer:

Yellow lasers lase on two different wavelengths of IR at the same time (solid state multiline laser anyone?). Then these two wavelengths go into a nonlinear optic and get frequency summed into 593.5

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I thought the IR wavelengths had to be doubled first and then summed to get 593,5nm

Uhm, as far as i know (and i have to admit that is not too much) about yellow DPSS units, the more common ones use a specific ND:YVO4 that, pumped from an 808nm diode, give back two frequencies, 1064 AND 1342 nm ..... then a KTP double and sum them and give out 593,5 nm ..... but i'm curious, anyone tried to diffract a yellow, for see if the two original wavelenghts are just mixed in the output expander, like with green and blue mixing, or if the doubling / combining process inside the KTP give out a single wavelenght ? ..... can't do the test myself, cause i still don't have one (at least, not until someone gift me one ..... j/k )

But i heard about other 2 types of units, that can give yellow (also if these are lab style units, and with extremely high costs) ..... one use a q-switched variable cavity, and can produce 532, 523, 527, 542, 555, 561, 589 and 593 nm, depending about how the cavity is set up, and another type uses a 532 nm green DPSS as source, and a "Raman" ( KGd(WO4)2 ) crystal, that can produce 8 different wavelenghts (555, 559, 579, 589, 606, 622, 636 and 658 nm), just changing the orientation of the crystal in the output coupler .....

How much types of yellow lasers exists, then ?

..depends, do you limit it to solid-state ones?

never heard of the latter type, thanks for the info!

(common) yellow lasers will all only emit one wavelength, nothing to find with a prism

manuel

To make a 473nm DPSS laser, you can get the pieces from a seller on e-bay. For a slightly more advanced version, you want an Nd:YAG rod with a pair of 20-40W CW diodes to pump it, a HR946/HR473/HT1064 plano mirror, a HR946/HR473/HT1064 concave mirror, a HR946/HT473 concave mirror, a collimating lens and a piece of LBO cut for NCPM SHG with a heater.

671nm DPSS would be simpler, but that's off topic.

What's wrong with Argon?

Uh, i suppose nothing is wrong with argon ..... maybe, just the fact that it's not exactly "pocket-size"

I think the OP was referring about modules for make handheld, pocket-size pointers (or at least, that was my impression).

Hey


CNI make 473nm Blue Modules from 1 to 50 mw with eather a 3volt or 5 volt pcb if anyone was intrested they are 26mm x 55.50mm

Price?

yobresal said:

Price?

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Hi

You would have to email CNI for the price of a single unit and PSU