Spectrometer readings of some common diode lasers

I finally got a surplus spectrometer. It is a little off, but consistently off. It reads HeNe as about 631.5 (~1.5nm low), DPSS green as 530.5(~1.5nm low), and single line argon as 486.5(~1.5nm low). So I am confident I can get precise readings within +/- 0.5nm with this calibration number of +1.5nm. It supposedly reads 380-910nm, but I've seen down to 360nm show up. It uses a fiber-coupled CCD.



red diode from PHR sled: 662nm

IR diode from PHR sled: 788nm

Atlasnova 635nm pointer: Starts out at around 633.5nm and warms up to 635.

eBay 405nm pens: consistently at 403.5nm.

GLP-808 CNI pen (can't find their 400mW version at the moment - same design though) initially showed as 807nm, but then another line at 805nm seemed to show up and overcome the 807.

PHR: one at 410.5nm and one at 409nm.

The $1 plastic pointers that use button cells started at 653nm and warmed up to 655nm.

These "650nm" modules commonplace in cheap projectors started out at 660nm and warmed to 662nm.

These red modules also commonplace in cheap projectors also started at 660nm and warmed to 661nm.

The 635nm module from laserwave in my projector holds steady at 639nm.

445nm diode at low power just turned on at 65F: 440nm. After five minutes on at 1A, the heatsink is 80F and the wavelength shifts to about 444nm.


(Don't forget to add 1.5nm)


I'll gladly measure for anyone if you pay shipping.

Here's a HeNe's discharge followed by a dying unfiltered green pen just for fun:

Nice info and a nice tool to own.

Ive been looking for a spectrometer for a while. I like those
screen shots, very cool indeed...

Any info on the one you have?

I dont know much about what is available, just know I want one :beer:

NVM, answered this myself...

http://cgi.ebay.ca/Compact-Fiber-Co...324?pt=LH_DefaultDomain_0&hash=item4aa63c6724

Cyparagon said:

445nm diode at low power just turned on at 65F: 440nm. After five minutes on at 1A, the heatsink is 80F and the wavelength shifts to about 444nm.

Click to expand...

Nice thread man! These spectrometers are damn cool. Can you tell me why there is a difference in wavelength at one laser at different powers?

Excellent thread, Sir! Do you have a LOC to try?

^I'm afraid not. But I suspect they're 660 as well.

DJNY said:

Can you tell me why there is a difference in wavelength at one laser at different powers?

Click to expand...

It's more to do with heat. When a laser diode heats up, the wavelength increases slightly.

That's one cool device you have there sir! I have found most high power 405s to run between 407-410 myself. Try getting a reading off of an LED just for fun. A good LED will have a band ~45nm wide!

Cyparagon...a bit older thread but.....

I have been looking at one of these for a while now. Do you use the fiber or just point your laser into the port? Also, have you found the software useful? It is a great price for what it is, even though it's still a pretty penny for most of us.

I have noticed that now they have "Unaligned" units for sale, seems complete but not aligned, perhaps someone might have some input on how hard it would be to align a spectrometer like this.:beer:

I have no idea how one would 'align' something like that.

Lasers (even class 2) are way too strong to shine in the fiber directly. You just get clipping on the readout. I point them at a piece of paper near the fiber opening.

The software is pretty nice. It supports:

• long exposures (but it also picks up some noise, too)
• linear or log views
• Zoom in either X or Y
• Zeroing function to weed out ambient light
• Continuous reading or single snap-shot
• Calibration

I had to calibrate mine (using known gas wavelengths). It was off by 1.5nm, but now it's spot-on. The calibration software doesn't come with the unit, but the seller or I can send it.

The only two things I wished it included was image export and CCT calculation. Screen-shots aren't too much of a hassle though.

Thanks for the mini-review.
They do look nice, I mailed the seller and he mentioned what you do with the paper or that you could just point the beam into the fiber opening too.
I figured someone here must have one of these, they are just too good a deal compared to any other compact CCD spectrometer.:beer:

Cyparagon said:

I had to calibrate mine (using known gas wavelengths). It was off by 1.5nm, but now it's spot-on. The calibration software doesn't come with the unit, but the seller or I can send it.

The only two things I wished it included was image export and CCT calculation. Screen-shots aren't too much of a hassle though.

Click to expand...

I picked up one of these as well. Can I get a copy of the calibration software?

Also, The unit I got though has a couple of 'hot' pixels on the CCD unfortunatly. It doesn't really affect actual usability, but with no input it shows a fairly large peak around 870nm I think it was or so. But it's only large relative to no signal other than the noise floor. With an actual input, that rogue peak usually turns in to a tiny bump.

A neon lamp from radio shack would give you some very well known cal lines for about 3$.

Spectral calibration

Steve

Good idea. Come to think of it, any fluorescent lamp would have the four mercury lines of 405, 436, 546, and 579. Although the 579 is sometimes hard to pick out from the phosphors.