DPSS Yellow laser pointers

[The_LED_Museum]

Forgot to add that my yellow laser pointer contact in the UK emailed me to say the shipment that was due today has been delayed about 1 week. So I probably won't have my evaluation unit for at least two weeks. /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/jpshakehead.gif /ubbthreads/images/graemlins/frown.gif

 

[sharkeeper]

This should be self explanatory folks! /ubbthreads/images/graemlins/smile.gif

Cheers!

 

[SkylineSelect]

[ QUOTE ]
sharkeeper said:
[*image*]http://www.laserglow.com/images/yellow3.jpg[*/image*]

This should be self explanatory folks! /ubbthreads/images/graemlins/smile.gif

Cheers!

[/ QUOTE ]

If only it was that simple.

The whole point is that digital cameras don't show up the colour very well. We'll know once we get our hands on them. I'm expectiong my stock any day now. (Within a week I hope)

 

[sharkeeper]

Adjusted as it appears in person.

Cheers!

 

[The_LED_Museum]

You know, I had a dream about these last night.
The part of the dream I remember places me and Brock N. at a cafeteria table; several other people were standing around, and I asked him when he would receive one of these yellow DPSS laser pointers for evaluation purposes. He said "1 to 3 weeks".
I woke up a very short time later. /ubbthreads/images/graemlins/icon15.gif

Two to three weeks seems to be about the correct timeline on these things; I wish it was one week though. /ubbthreads/images/graemlins/wink.gif

 

[14C]

sharkeeper...

very cool......regardless of the exact color rendition.

 

[The_LED_Museum]

Just got an email from Roithner Lasertechnik (www.roithner-laser.com) and they are advertising yellow laser pointers: 0.6-2.0mW for $190.00, and 2.0-5.0mW for $540.00.

 

[SkylineSelect]

This guy must be getting a LOT in if he can afford to sell them at that price.

It really does bother me when people start selling things much lower than nessersary, as it forces every one else to.

Well, I'll see how my market goes ;-)


Iain.

 

[The_LED_Museum]

They're also offering violet (410-420nm) directly-injected laser diodes for $1,020.00 (50mW) and $1,560.00 (200mW).
These are just the diodes themselves, and do not include collimating lenses or drivers.
Threshold current is 500mA, and maximum current is 650mA.

Now I'm dragging this thread off-topic...somebody please put this train back on the correct track. /ubbthreads/images/graemlins/wink.gif

 

[idleprocess]

It's easier to derail a train than to "re-rail" it.

 

[Myx]

quote from Skyline Selects site....

[ QUOTE ]
Yellow laser pointers are up to 60 times brighter than regular red laser pointers. This means that the brilliant yellow dot can be seen though the bright light of overhead projections and PowerPoint presentations. Yellow is the colour that is most visible to your eye, so will apear much brighter than any other colour laser pointer.

[/ QUOTE ]


I thought the eye was most sensitive to 555nm, which is green, not yellow?

 

[Uisgdlyast]

Your eyes are actually sensitive to many different colors, read how vision works on howstuffworks.com

Plus you can word anything so it is partially true

 

[The_LED_Museum]

According to that chart, the "red" cone would be most sensitive to the 593.5nm radiation output by these yellow laser pointers, the "green" cone most sensitive to the 532nm radiation output by green laser pointers, and the "blue" cone most sensitive to the 488nm radiation output by single-line argon ion lasers.

The peaks for each cone (except for the green and the blue) seem to correspond quite accurately with the three laser lines I just described. And even the blue and green cones' wavelength response isn't all that far off from maximum.

 

[comozo]

A good tutorial on this subject.
http://www.ndt-ed.org/EducationResources/CommunityCollege/PenetrantTest/Introduction/lightresponse.htm

 

[SkylineSelect]

[ QUOTE ]
Myx said:
I thought the eye was most sensitive to 555nm, which is green, not yellow?

[/ QUOTE ]

Yes that is true, but green laser pointers are 532nm, which is an equal distance from the optimum as yellow. Therefore yellow will be equally as bright as green, when you are talking about these wavelengths, (in laser pointers).


Iain.

 

[PeterW]

593.5nm will appear yellow/orange. Yellow sodium lights
emit at 589, so almost the same colour.

DPSS==Diiode Pumped Solid State, ie in green pointers an 808nm diode pumps a Nd-YAG crystal to produce 1064nm light.

How are they doing it?? I am not sure about diodes emitting at this wavelength and there certainly are no diodes emitting at double the wavelength. 1187nm could be reached by a raman fibre laser easily, but that won;t fit in a pen sized container! You easily find 1064nm, 532 and 266nm as these are subsequent doublings of the commonly available 1064nm Neodymium laser wavelength.

Sum Frequency generation.... would give low output, especially as you need to generate two wavelengths to do it.

I think that 532 ought to be more visible as atmospheric scattering scales as the inverse 4th power, so shorter wavlengths rule (compare a red and green pointer).

Just checked Rothinir, they do high power yellow diodes using InGaAlP so it is normal semiconductor laser, nothing funny, except using a pretty new and exotic material mix.

PEterW

 

[The_LED_Museum]

[ QUOTE ]
PeterW said:
Just checked Rothinir, they do high power yellow diodes using InGaAlP so it is normal semiconductor laser, nothing funny, except using a pretty new and exotic material mix.

[/ QUOTE ]
You mean Roithner's yellow laser pointers are directly-injected, and do not use NdYVO4 and KTP crystals? /ubbthreads/images/graemlins/eek.gif /ubbthreads/images/graemlins/wow.gif /ubbthreads/images/graemlins/eek.gif

 

[SkylineSelect]

If you look back through this thread, you can see how they are made.

http://www.candlepowerforums.com/ubbthreads/showthreaded.php?Cat=&Number=645376&page=0&view=collapsed&sb=5&o=365&vc=1


Iain.

 

[PeterW]

OOOpppsss, sorry for being a bit thick. Just found the following that explains it, just replace YVO4 with YAG. I hadn't realised that Nd had a 1340nm emission window.

http://ychuang.ee.nthu.edu.tw/PDF%20and%20DOC/publications/nonlinear%20optics/12.pdf

Very interesting. Wait till they get a bit cheaper and I am sure that it'll top my xmas list.


Cheers

PEterW

 

[The_LED_Museum]

My contact in the UK for yellow laser pointers says his shipment is en route to him as of yesterday, so I might have my evaluation unit here in a week or so. /ubbthreads/images/graemlins/smile.gif