What's difference 635nm, 637nm, 638nm, 640nm?

[Bradfo69]

As I understand it, 650 and 635 both suffer from having the worst beam (largest size and divergence). 640 and 642 I have heard people say are the same and companies use the number interchangibly. But basically 640 has the best characteristics for the reds. It's also the most expensive. 638 and 637 obviously have some differences because even companies that carry both in their product offerings charge more for 637 and I believe it has the better beam profile.

Then again... it's red so, who the heck knows.

[ablelaser01]

How many pcs did you buy?

[yeping123]

In the past i sent many many emails to some potential customers who need laser projector, and i got some replys like " i bought a same power rgb laser with 637nm red from **company from China just cost me ** US dollar. Your price is too high" Normally i will ask which company especially beam diameter and divergence. and i was told that some compaies' 637nm red is ＜2mrad divergence and ＜4-5mm diameter even has ＜3mrad, For ABLE 637nm rgb laser, it is ＜1.0mrad divergence @3mm diameter.
But our rgb laser with 635nm is ＜1.5mrad divergence, Our 635nm laser is EVEN BETTER than some other companies 637nm rgb laser. but we know 637nm is actually better than 635nm. So I totally understand my colleague ablelaser01, not surprised at all, she may also find this interesting thing, i think.

[Song]

Wrong information.
Wrong information.
Wrong information.
Wrong information.
Wrong information.
Wrong information.

[JasonB]

Attachment 42641

1W 655nm CNI Torch , right 400mW Mitsu G71

JRGixxerfreaK1, Thanks for that picture. Just to double check, it demonstrates that 635/638 looks brighter to the eye than 655 with twice the power. You are combining two Mitsu G71 diodes , correct ?

I'd also like to hear other people's thoughts regarding Song's comments on beam profile for reds. I have to ask, because my RGB PJ has one 638nm red and the beam profile and convergence is beautiful, almost exactly the same as my 100mW 532mW lab laser module. So I'd really like to know if Song's comments are correct (wavelength being the deciding factor defining beams) or does it vary laser to laser with the same wavelength ?

I ask this because my 455 has an UGLY rectangle beam I'm thinking could use Anamorphic Prisms For Laser Beam Correction to get a nicer round dot...

Just trying to learn if its possible to generalize beam profiles like this ----

[danielbriggs]

655nm, it looks like a square.
635nm, it looks like a cross, Div. is big.
638nm, it looks like a cross, Div. is smaller than 635.
637nm and 640nm, looks like a spot.

This is ludicrous...
The wavelength alone does not determine the beam propagation.
The specific laser used, and hence it's resonator, does; obviously.

[JRGixxerfreaK1]

JRGixxerfreaK1, Thanks for that picture. Just to double check, it demonstrates that 635/638 looks brighter to the eye than 655 with twice the power. You are combining two Mitsu G71 diodes , correct ?

I'd also like to hear other people's thoughts regarding Song's comments on beam profile for reds. I have to ask, because my RGB PJ has one 638nm red and the beam profile and convergence is beautiful, almost exactly the same as my 100mW 532mW lab laser module. So I'd really like to know if Song's comments are correct (wavelength being the deciding factor defining beams) or does it vary laser to laser with the same wavelength ?

I ask this because my 455 has an UGLY rectangle beam I'm thinking could use Anamorphic Prisms For Laser Beam Correction to get a nicer round dot...

Just trying to learn if its possible to generalize beam profiles like this ----

Jason,

It was single overdriven G71 Tec cooled with Dave's correction kit

Some more pics

[steve-o]

Years ago I bought some samples of a 635nm diode from Mitsubishi. Very expensive for 150mW back then. The packages were labeled with the exact wavelength and power output @ current. I believe what the package label reads and/or the official spec-sheet for the particular product (laser diode, dpss/etc) would be the determining factor as to the exact wavelength and the other optical properties. Saying that a "635 diode is different than a 638" is a random comparison of probable different brands and lacks detailed information for an accurate analysis.

[norty303]

This is ludicrous...
The wavelength alone does not determine the beam propagation.
The specific laser used, and hence it's resonator, does; obviously.

I couldn't agree more.

Even worse that this information is both being asked by, and coming from laser projector manufacturers.

Clearly the only reason some of them look like a big cross is because they're using dual diodes through a cube with no waveplate or correction optics!

[andy_con]

single mode lpc 660nm diode = amazingly small beam

briggs... nail... head...