Unexpected peaks in spectrum of halogen lamps

[RicoW]

Hello all of you, I hope you can help me out here.

 

I'm doing some spectral experiments at university, and I recorded the attached spectrum of a halogen lamp with an integrated reflector.

But there are two additional local maxima in the spectrum, at around 806 and 910 nm. I just can't figure out what the source of these is.

 

I hope I'm at the right place for such answers here.

 

Thanks in advance,

Rico

[John Cuthber]

I think you have troughs, rather than peaks.

Something is absorbing light near 790 and 890 nm, rather than emitting near 810 and 910.

It could be pretty much anything in tth light-path.

[koti]

Hello all of you, I hope you can help me out here.

 

I'm doing some spectral experiments at university, and I recorded the attached spectrum of a halogen lamp with an integrated reflector.

But there are two additional local maxima in the spectrum, at around 806 and 910 nm. I just can't figure out what the source of these is.

 

I hope I'm at the right place for such answers here.

 

Thanks in advance,

Rico

 

Did you use an integrated sphere for you experiment or a similar closed system that would eliminate outside interference ?

A time axis would be nice too.

Assuming that you performed the experiment in a closed environment, the source is your halogen lamp.

Note that halogen lamps nor any other sources of light never give absolutely uniform outputs. There are fluctuations due to various reasons.

In your case, I suspect that the source is fluctuating in the IR wavelenght region due to the halogen technology...the gass bombarded by electrons in your halogen bulb simply fluctuates enough for your spectrometer to detect it. These fluctuations will be present especially at turn on and turn off of the source. A stabilised halogen source (let it run for a minute or so) should be more uniform.

Edited October 21, 2016 by koti