Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Mitts 500 WL shift due to amperage decrease/increase. Thoughts

Joined
Aug 16, 2013
Messages
966
Points
43
Hey folks,
Help me wrap my mind around something.
When we talk about wavelength shift the first thing that comes to mind is the gain we achieve with the 462s. My Ndb7576 spectro'd at a whopping 471nm @ 2.6A! Greater amperage equals increase wavelength and apparent brightness.
Now, how does this apply to reds I.e. 638s and 650s?
Take the mitts 500mW. If you drive it at the data sheets recommend 650mA you get 638.

If we over drive these diodes to say 1A. Which way does the wavelength shift? Greater than 638? Maybe 641? These are arbitrary numbers I don't have a spectrometer. A shift higher here would appear darker in color to the human eye but brighter in apparent power.
So what's the point here? If you wanted to achieve a more orange color you would under drive these diodes and sacrifice power.

This idea is inverse from blues because we are on the opposite side of 555nm. The peak of visible acuity.

Here is a chart from the data sheet. If the current and temperature to the diode is decreased the WL will shift lower. Even if a few nm is not noticeable to the human eye.



Does this make sense or is it just too early in the morning for me to process? :tired:
This is a precursor to an experiment I might do this summer on red shift.
 
Last edited:





I characterized the 300mW when it came out, but not the 500mW. I'm sure they're quite similar, however. You can probably expect ~645nm at the obscene over-driving people do here.

Mitsubishi%20638nm%20300mW.png
 
Yes, thank you very much. That last chart you linked is very useful. It is true we tend to over drive these diodes but regarding the mitt 500 I would probably run it closer to spec to achieve the lowest wavelength. Just an idea for A future build. I know this isn't a new topic by any means but it is a project that might be in the works. I don't think I have any builds in this part of the spectrum!
 
well styropyro manage to bring the wavelength down to the orange area... after dip it in LN2.
 
Yes! That thread and video was awesome. One goal would be to cool the diode and still maintain a coherent beam and if possible portable. I.e garage range portable. I have plans
 





Back
Top