B&W-tech Spectrometer & 473 module: Setup+Mods+Info

[NightLase]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Heres a nice little unit for sale from coherent in the US, might be possible to use it with the discharge lamps, would have to look up the model number to find the output V

https://www.ebay.de/itm/Coherent-31...997962?hash=item1caa490b0a:g:txIAAOSw7RdZxVN9

Keep in mind that HeNe Lasers operate from a DC supply, for some of these simpler discharge lamps will require AC and or High-frequency “RF”. DC will cause sputtering of the electrodes and decrease it’s lifespan.

Another good supply is CCFL drivers for small lamps, you can even use the drivers from a disposable camera with Flash.. the will develop around 360V from a single AA battery.

 

[Agastar]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Keep in mind that HeNe Lasers operate from a DC supply, for some of these simpler discharge lamps will require AC and or High-frequency “RF”. DC will cause sputtering of the electrodes and decrease it’s lifespan.

Another good supply is CCFL drivers for small lamps, you can even use the drivers from a disposable camera with Flash.. the will develop around 360V from a single AA battery.

Yeah! I'm pretty sure I still have the one I converted a while back and it runs off of a AA battery as well

 

[Mosc007]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Last night i ordered a set of Nobel Gas Ampules from an Ebay seller. I need about 2kv A.C. supply to charge them but that should not be to difficult.

The Seller is "novaelementscom" and a set of 5 Ampules (Helium, Neon, Argon, Krypton, Xenon) was $80 AUD + $10 AUD delivery from Italy.

 

[paul1598419]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Cool. You should be able to excite those with any cheap Chinese HV supply that runs on batteries. I believe you can get one for under $5.00. The higher the frequency the better. You should have no problem getting a good calibration using these lamps.

 

[Agastar]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

On the science-surplus site, the mention this ...

We also install a basic order sorting filter to reduce stray light from higher diffraction orders.

Does anyone know what this is and if so, do you have any links to information on it?

Thanks
John

 

[jnrpop]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

So a huge thank you to a fellow forum member here, who will for the moment go as anonymous until he chooses :beer:

I recently sent my unit of to be calibrated using an array of known spectral lines, and have received the unit back. Had some time tonight to measure my lasers after the recent calibration and i must say i'm impressed with the results, and the accuracy, afaik

Here are the diodes / measured wl.

475 diode - 474.1nm
488 pocket - 488.28nm
488 PLT5-488 - 489.05nm
495 diode - 494.08nm
<505 diode - 503.23nm
<510 diode - 507.66nm
520 diode - 513.05nm
532 dpss - 532.14nm
638 diode - 638.43nm
405nm diode - 409.94nm
470 diode DTR Overdrive - 465.01nm

J :beer:

 

[paul1598419]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Good for you, Corey. Sounds like you got all the kinks works out. That 532nm line couldn't get any closer. I believe the main line out is 532.14nm. That is where my Ocean Optics sits for my 1300 mW 532.14nm laser.

 

[diachi]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

So a huge thank you to a fellow forum member here, who will for the moment go as anonymous until he chooses :beer:

I recently sent my unit of to be calibrated using an array of known spectral lines, and have received the unit back. Had some time tonight to measure my lasers after the recent calibration and i must say i'm impressed with the results, and the accuracy, afaik

Here are the diodes / measures wl.

475 diode - 474.1nm
488 pocket - 488.28nm
488 PLT5-488 - 489.05nm
495 diode - 494.08nm
<505 diode - 503.23nm
<510 diode - 507.66nm
520 diode - 513.05nm
532 dpss - 532.14nm
638 diode - 638.43nm
405nm diode - 409.94nm
470 diode DTR Overdrive - 465.01nm

J :beer:

Not sure how you're managing to get those down to two decimal places given the resolution of these units isn't that good... But that's good you got it calibrated. :beer:

 

[paul1598419]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

It doesn't have that much resolution. It is just left over insignificant figures from the calibration equation. That is why I cut mine off at the first place after the decimal point. My Ocean Optics has a resolution of 0.2nm. So, in truth, that is as close as I can get it.

 

[Cyparagon]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Not sure how you're managing to get those down to two decimal places given the resolution of these units isn't that good...

By the same method that a +/-10% hobby power meter can measure a laser at 1,729.8 milliwatts.

(laymen don't know what sigfigs are)

 

[jnrpop]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Good for you, Corey. Sounds like you got all the kinks works out. That 532nm line couldn't get any closer. I believe the main line out is 532.14nm. That is where my Ocean Optics sits for my 1300 mW 532.14nm laser.

Happy with the results so far, but they have come only through the supportive community here working together. Quite a few members on LPF have these units now, and im sure continue to hold high hopes for them

By the same method that a +/-10% hobby power meter can measure a laser at 1,729.8 milliwatts.

(laymen don't know what sigfigs are)

^ the same way, yes. It was the Spectrum Studios exact peak output measurement ( to 2 sigfigs :crackup: )
Its obvious resolution comes into play, as with most Spectrometers. Interesting enough these peaks did not shift, even after 2-3 spectral captures of each wavelength i tested.

Its great to feel, for the most part, the members in this thread are working together in such a positive fashion, with supportive remarks and constructive, helpful information.

The theme of this thread is based on the "non-functioning" spectrometers from these ebay units, and to have a community here that together has produced seemingly relevant results is the whole reason i am apart of it.

@Cyparagon, comments like this "laymen don't know what sigfigs are" don't support out community and create positive forward motion, they are unnecessary!. A few members here have already expressed they were reluctant to post information due to certain members here "Purely criticizing" their posts only concentrating on the information they could out-wit.

J

 

[Mosc007]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

I would redo the calibration leaving out the direct diodes as they are likely adding error to your calibration. Only use He-Ne lasers, DPSS lasers and other mercury/argon vapor sources. Then your calibration will be as accurate as you can get it without doing a realignment. Only measure your direct diodes after calibration and see how close they are then.

I just redid the Calc leaving out the 462 Diode and the 650 Diode. Just using lines from the 473 DPSS and the CFL.


The Sharp 490 now reads 489.0 nm. That is in the range DTR tested them at.

The 505 nm I got from DTR now reads 508.2 nm which is probably correct. On DTR's site he said most of the 505's he tested were around 508 nm.

 

[Mosc007]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Seems there has been a bug in my software since the first release with the Com port detection. I am surprised no one mentioned it to me. The PC I was using it on had no hardware Com ports. The Only Com port was a USB to Serial Adapter.

I just changed to a new PC which has 2 Onboard Com Ports. My Software was only showing the first Com port it found. And other Com ports were not shown in the list. It was a silly Bug in the Com Port detection part of the code. It has now been fixed. I have 2 hardware Com ports and a USB Com port. The Software now shows all 3 Com ports in the list.

I have also updated the Version to 1.5 and again it's only the exe file. If you have not used it before you will need the full install file earlier in this thread.


Version 1.5 of my Spectro

 

[LSRFAQ]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Be real careful, 532.1 has a 1.1 nanometer gain bandwidth and a second weak line about .35 nm longer then the primary at the right edge (longer wavelength) of the spectrum. A good spectrum of a free running DPSS shows TWO lumps close together. I used to do Brilliouin spectroscopy and even the highly prized C315 Stabilized DPSS could be anywhere in the gain bandwidth and out of four tested all ahad a weak spike of a second longer wavelength. The only way to know for sure where 532 is lasing at is lock it to iodine cell or other frequency locking means. I should mention the number below is for ND:YAG. Common ND:Vandate pointers are ever so slightly different on their centers and bandwidth.

472.3 nm DPSS ND:YAG has a +/- 0.3 nm gain bandwidth.

Yellow DPSS ND:YAG :

561.2 +/- .32 nm Gain Bandwidth


I'll give you some accurate numbers from a database at work... . Letters are notes about ionization states..
Wavelenths are shown corrected for propagation in AIR, they are often shown as what the wavelength is in a vacuum.
Wavelengths are in Angstroms, shift decimal to left by one digit for Nanometers.

Mercury: Spectral Lamp (May also be present in CFLs)

4339.223 Hg I
4347.494 Hg I
4358.328 Hg I
5128.442 Hg II
5204.768 Hg II
5425.253 Hg II
5460.735 Hg I
5677.105 Hg II
5769.598 Hg I
5790.663 Hg I
5871.279 Hg II
5888.939 Hg II
6146.435 Hg II

Hydrogen Spectral Lamp (Glow Discharge)

3970.072
4101.74
4340.462
4861.2786
4861.2870
4861.3615
6562.7110
6562.8518




Argon Laser
488.906
514.51

Green HENE
543.36

Multiline HENE (REO) Confirmed in Spectral Database and yes I have these lines lasing.
611.801
614.25
629.37
632.819
635.191

SEALED MIRROR HENE COMMON RAMAN LINE, aka 650 in Sams FAQ, lases in all my REO tubes that were made for particle sensing.
649.992 ± 0.002

Steve

 

[Mosc007]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Some very useful information. Thanks.

I have done a bit more checking on the CFL lines and the ones I used are slightly out. The author of the graph I used showed the measured lines. Not the actual lines. Eg, The Mercury line at 546.1 was shown as 546.5

I will do my calc again using the true spectral lines which should improve accuracy a bit more. He did supply a document showing measured wavelength and true wavelength. I mistakenly used the measured data instead of the true data.

 

[diber]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Found another source of plenty of lines throughout the spectral range for these spectrometers: spark emission of metals. With the collimating lens of one of the beam splitters, the optical fiber and a re-wound microwave oven transformer (replacing the high voltage winding by a few turns of thick electrical wire... you can find the procedure on youtube for DIY spot welders based on microwave oven transformers), you can generate sparks between 2 metal pieces and record the spectrum. I got the inspiration from the youtube movie on the science surplus site. Gives plenty of spectral lines and if you can assign them to specific elements, you can use the build-in database in Spectrum Studio to get calibration points. According to the help file of Spectrum Studio, they used an extract from the NIST atomic spectra database to produce the tables used in the program.