1
vote
1answer
25 views

What will be the effect of placing a light source very close to a photodiode?

What will be the effect of placing a photodiode really close to a laser source and what should be the appropriate distance between a light source and photodiode to get maximum output current?
2
votes
1answer
34 views

How is “Band Intensity” related to absorption coefficient

I am interested in the linear absorption of 762nm light near a transition of molecular oxygen. I need to find some experimental numbers that will tell us how far the 762nm light will propagate before ...
1
vote
1answer
26 views

Equivalent temperature: laser and cell containing Rb

What's the meaning of "equivalent temperature" related to a cell containing rubidium and crossed by laser?
2
votes
3answers
99 views

How to smooth the spectrum of a light source?

Could somebody please tell me if there's a reasonably cheap substance or device can I use to smooth the spectrum of a light source? For example, if the spectrum has spikes as in the blue graph below, ...
0
votes
2answers
353 views

Diffraction Grating Spectrometry Question [closed]

Yes, this is a homework question, but I've already failed to solve it enough times that the online system hosting it isn't going to give me any marks, so I figure it's a good time to stop hitting the ...
1
vote
2answers
2k views

Full Width Half Maximum (FWHM) of a transmission spectrum

I have a transmission spectrum of a material which has been fit to a Lorentzian. According to Wikipedia here and here, FWHM is the spectral width which is wavelength interval over which the ...
3
votes
0answers
47 views

SHS Interferometer and diffraction limit

I'm currently researching Spatial Heterodyned Spectrometers (SHS) and I'm a bit at a loss understanding the influence of the diffraction limit. I'll be measuring a diffuse visible light source with ...
2
votes
0answers
100 views

Line-shape asymmetry in undergraduate Hydrogen-Deuterium experiment

I'm working as an LA (undergraduate TA) for an undergraduate physics laboratory experiment where students test the Bohr model and use reduced mass to determine the approximate mass of the neutron. In ...
0
votes
1answer
518 views

Calculating Kramers-Kronig using Mathematica

First of all, I know there is a Mathematica group in beta, but I don't think the problem of the following is directly a Mathematica issue. I am trying to calculate the change of the refractive index ...
3
votes
2answers
3k views

Glycerol: refractive index & absorption spectra in 0.2-0.4um range

Could anyone suggest where can I find absorption spectra & refractive index of Glycerol? I am specifically interested in UV range, 200-400nm, everything I was able to find out was for standard ...
5
votes
1answer
3k views

Newton's color Disk

How does Newton's color disk work? Newton's disk - Take a circular white color disk, make 7 equal intersections and paint section with respective VIBGYOR colors, now when you spin the disk in certain ...
11
votes
2answers
4k views

Why is a plastic bag transparent in infrared light?

This is a classic trick to do with a IR camera: Bu why is the plastic bag transparent, while the glasses aren't? I've also heard that water is not transparent in IR light. What causes this ...
6
votes
2answers
1k views

Converting between brilliance, intensity, and flux

This one should be a bit of a softball, but I can't find it explicitly stated anywhere on the internet, and my basic unit analysis doesn't seem to work. Suppose you have a beam of synchrotron ...
2
votes
3answers
138 views

Can a multipass x-ray absorption cell be constructed?

I've been trying to understand the various concepts behind x-ray optics compared to standard visible/IR optics like mirrors and such. However, the x-ray mirrors I've been finding typically have ...
1
vote
1answer
136 views

How much can a laser's position be fine-tuned?

Suppose you wanted to do a time-resolved experiment with a molecular beam traveling at, say, 300 m/s involving a mobile excitation (pump) laser that scans across the length of the molecular beam and a ...