Plastic or glass that can block one colour/ wavelength?

Click For Summary
SUMMARY

The discussion centers on the existence of transparent materials that can block a specific wavelength of light while allowing all others to pass through. Participants confirm that notch filters, particularly those used in Raman spectroscopy, serve this purpose effectively. These filters block a narrow band of wavelengths (the stopband) while permitting nearly all other wavelengths to be transmitted. Interference filters, which utilize multiple layers of transparent materials, are highlighted as a more effective solution than pigments or dyes for achieving precise wavelength filtering.

PREREQUISITES
  • Understanding of optical filters, specifically notch filters and line filters.
  • Familiarity with Raman spectroscopy and its applications.
  • Knowledge of wavelength versus color in the context of light and optics.
  • Basic principles of interference filters and their construction.
NEXT STEPS
  • Research the specifications and applications of notch filters in Raman spectroscopy.
  • Explore the design and functionality of interference filters and their use in optical devices.
  • Investigate the differences between line filters and notch filters in optical applications.
  • Learn about the principles of light interference and its practical applications in optics.
USEFUL FOR

Optical engineers, physicists, and anyone involved in the design or application of optical filtering technologies, particularly in spectroscopy and imaging.

CuriousRupert
Messages
1
Reaction score
0
Hi, new member here, I know very little about physics so have no idea if this is a very basic question or not, but I was wondering if anyone knows the answer to the following:

Does there exist a type of plastic or glass that (whilst remaining completely see through) can allow the user to see every colour through it except for one?

Thanks.
 
Science news on Phys.org
Look up notch filters. They are used, for example, in Raman spectroscopy.
 
DrClaude said:
It's called a filter.

yes but doesn't quite fill the OP's comment ... definitely not optically transparent at other wavelengths

CuriousRupert said:
whilst remaining completely see through
nasu said:
Look up notch filters. They are used, for example, in Raman spectroscopy.

http://www.semrock.com/filter-types-for-raman-spectroscopy-applications.aspx

Maybe the same problem sure ? ... only looked at a couple of sites

I wonder if visually looking through it if it appears transparent to everything ( like a sheet of clear glass) other than the notch wavelength ?
that is what the OP is asking :)

Dave
 
davenn said:
yes but doesn't quite fill the OP's comment ... definitely not optically transparent at other wavelengths

http://www.semrock.com/filter-types-for-raman-spectroscopy-applications.aspx

Maybe the same problem sure ? ... only looked at a couple of sites

I wonder if visually looking through it if it appears transparent to everything ( like a sheet of clear glass) other than the notch wavelength ?
that is what the OP is asking :)

Dave

The line filters from that site appear to be exactly what the OP is looking for...
 
Pretty much any optical filter that blocks only a small range of wavelengths will do. The notch filter from the link above works perfectly. It blocks practically all of the light within the notch's wavelength range (stopband) and allows almost all of the light outside of this range to pass through. The line filter does the opposite. It blocks everything except a small range of wavelengths from passing. I have a filter in my astrophotography camera's filter wheel that works identically to the line filter. It only allows light around 656 nm to pass through. I believe the passband is about 10 nm.

Wavelength is a better term to use here than "color" because color is both subjective and lacks an accurate way of measuring it. The color "red" exists over a wide range of wavelengths, and many people would disagree about where the color red begins and ends. There is no confusion if you use "wavelength" instead.
 
Drakkith said:
Wavelength is a better term to use here than "color" because color is both subjective and lacks an accurate way of measuring it.

Exactly :) which is why I did

cjl said:
The line filters from that site appear to be exactly what the OP is looking for...
( http://www.semrock.com/filter-types-for-raman-spectroscopy-applications.aspx )

the notch filter, at least going by the graph ( lower right) would be OK. I was initially put off by the colouring of the filters used in their drawing but that was for the edge filters

the line filter ( as in the lower left graph) appears to be a narrow band pass which wouldn't be any good as it would have the opposite effect to what the OP wants

Dave
 
Oh - you're correct. I was reading the graphs backwards.
 
It's worth while pointing out that filters as precise as the ones in that link are seldom achieved with pigments or dyes. They will be Interference Filters, made with several layers of transparent materials, each of around a quarter the wavelength of the light, The multiple reflections between the layers ( at each interface) will cause constructive and destructive interference of different wavelengths. Interference filters are used to stop reflections on the surfaces of lenses (blooming of camera and binocular lenses) and to produce the stunning colours that you can get on thin oil films on water or in butterfly wings and bird feathers. Trying to do the same thing with pigments is hopeless because the way light interacts with the molecules in dyes is much less well defined.
See 'Dichroic Filters' in this link.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 21 ·
Replies
21
Views
2K
Replies
4
Views
3K
Replies
21
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 6 ·
Replies
6
Views
5K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 7 ·
Replies
7
Views
5K