Make Your Own Spectrometer for Under $1

[Pman]

So what nd am I looking for? How far do I need to knock the power down for those cheap filters?

 

[CurtisOliver]

Sorry OD 2.0 should be sufficient. This would make even the NUBM44 70mW max. This should be a safe power level for the diffraction film.

 

[Pman]

K, looking at Amazon as I would like to order in the US

 

[CurtisOliver]

Ok, I'll have a look for you to see if there are any US sellers for a reasonable price, whilst you check Amazon.

Edit: If you follow the link I have sent you, they have a US site.
It is $22.50 for Absorptive, and $28.50 for Reflective. For the reflective, it is specified for 0 degrees incidence angle. Just slightly reflect the beam to the side and the specs should not differ too much. As for the Absorptive, there is no info on damage threshold but it does start too deform at 490 degrees Celsius.

 

[Pman]

Well I just ordered a 3 pack of nd2, 4 and 8 so we will see what happens. Only $15 so not a big deal. I'll get everything Sunday. Cool that Amazon basically delivers everyday now regardless of Sunday or holiday.

 

[CurtisOliver]

Not a bad price. Can you send me the link as it could be useful for me as well.
Amazon is good nowadays.
Curtis

 

[HydroSean]

Well I just ordered that pack of gratings from Amazon. What cheap filter would I need that they sell at Amazon to knock the power down enough for lasers in the 3-7W range? I see a 3 pack of 3 different ones but it's meaningless to me.

I used my NUBM44 set at 7W and it worked just fine through the plastic grating. Just don't let it hit the paper part or it will set fire :eg:

 

[CaliKirk]

I used my NUBM44 set at 7W and it worked just fine through the plastic grating. Just don't let it hit the paper part or it will set fire :eg:

I also have a plastic 1000 line and it hasn't burned yet with full power of 07e and 44 on it so I think you'll be okay, although I'd imagine not all gratings are made to the same spec so Pman is probably on to something with bouncing the beam off something first to be safe.

Thank you for sharing this, I have done some tests on cheap 532s in the past and have came up with multiple lines on more than a couple of the ones I have. I'd love to actually follow the correct way of doing this in order to cypher what 8 wavelengths I'm getting. To the eye all 8 spots are different in color and intensity so who knows..

 

[Mattronium]

I also have a plastic 1000 line and it hasn't burned yet with full power of 07e and 44 on it so I think you'll be okay, although I'd imagine not all gratings are made to the same spec so Pman is probably on to something with bouncing the beam off something first to be safe.

Thank you for sharing this, I have done some tests on cheap 532s in the past and have came up with multiple lines on more than a couple of the ones I have. I'd love to actually follow the correct way of doing this in order to cypher what 8 wavelengths I'm getting. To the eye all 8 spots are different in color and intensity so who knows..

Wow, 8 lines is impressive for 532nm! The best one I have does six.

How I measured the 532nm wavelengths was to assume that the first, strongest line was 532nm. (if you look up the transitions of ND:YVO4, you see that there are two levels that fall into six possible levels. (4F3/2 --> 4I11/2), R1 & R2 go to Y1, Y2..... Y6.)
When I assumed 532.1nm for the reference line I got: 537.2nm, 542.3nm, 544.8nm, 549.5nm. Of coarse the final answer will have three digits of precision.
My assumption that 532nm was the strongest could be wrong though.


Here is a thread I just posted for specifically discussing 532nm DPSS lines: http://laserpointerforums.com/f45/m...dpss-lasers-discussion-98658.html#post1442523

 

[CaliKirk]

Matt- I am going to try and set something up at the house that will actually allow me to get some sort of idea. I have a couple that have 6 lines, one with 4 lines and a bunch that stay in 532.. the one with 8 lines stays that way no matter what temp.. weird

I have seen this thread awhile back about another multi line 532 and that's why I got a grating but never took it any further..

 

[paul1598419]

I don't know about the singles sold on Amazon, but the sheet I got several years ago will take over 3 watts easily and not get hot or distort in any way. It appears clear in normal lighting and is made of a stiff plastic. Had I known you were thinking of ordering the Amazon ones, Pman, I'd have sent you a large piece of the one I have.

 

[Benm]

I'd they could be more easily damaged by laser power, but apparently that doesnt seem to be a big problem.

Perhaps a solution could also be to mount the film between two pieces of glass (microscope slides or something) to dissipate the heat a bit better, but i guess that would give problems with internal reflections.

 

[Cyparagon]

I pointed this out five years ago.

http://laserpointerforums.com/f44/make-your-own-laser-spectrometer-62605.html#post890672

 

[HydroSean]

I pointed this out five years ago.

http://laserpointerforums.com/f44/make-your-own-laser-spectrometer-62605.html#post890672

Great tut! I'll link it in this thread

 

[CaliKirk]

So I managed to follow the instructions and ended up doing it 3 times for consistency. Maybe I'm doing this wrong or I have the angle of laser to grating off a tad and I am thinking of another way for me to set something up that's more exact with perpendicular angles. Unfortunately I ran out of time and was only able to test the 8 line that I have, but here are the lines I'm coming up with...

1) 527nm
2) 532nm
3) 534nm
4) 536nm
5) 539nm
6) 542nm
7) 544nm
8) 547nm

I was only able to come up with even numbers and I noticed others didn't. So I must be doing something wrong!!

 

[HydroSean]

The laser should be perpendicular to the grating and the grating should be parallel to the wall. For more precision you should do it at least 15ft away. Also use as many decimals as possible in the calcukation (6 should be good) until the end result, then round off. Hope this helps