Becca Posted March 14, 2007 Report Share Posted March 14, 2007 i am investigating the brewster angle of wet sand for a lab project and it would be really usefull if i had somethng to aim for as the refractive index so i'm researching the varying refractive indx of water over different wavelengths. i first really need it in infrared wavelengths but it would be good if anybody knew of a graph of the variation so i can see the whole range. i have searched the internet for hours now and the only sites that look usefull are the ones where you have to pay to read the journals. please help as i'm becoming increasingly frustrated with my fruitless searching. becca Quote Link to comment Share on other sites More sharing options...
eric l Posted March 14, 2007 Report Share Posted March 14, 2007 Hi Becca, Using an other language with Google can be helpful. I tried in Dutch and got this for a second page :Brekingsindex The page also gives a link to a table with other refractive indices at different wavelengths. Just to make things a bit easier, here are the values for water : 687 nm (red) : 1.330 589 nm (yellow) : 1.333 486 nm (blue) : 1.337 434 nm (violet) : 1.341 I'm sorry, the site does not list infra-red wavelengths. But water does absorb most of the IR. Quote Link to comment Share on other sites More sharing options...
Becca Posted March 14, 2007 Author Report Share Posted March 14, 2007 wow, thanks, i never thought of searching in another language. how did you ever think to try that? also didn't you find that the pages were in dutch? oh well, thanks very much. :esad: :) :) Quote Link to comment Share on other sites More sharing options...
max4236 Posted March 14, 2007 Report Share Posted March 14, 2007 I found this graph of the Absorption Coefficent of Water vs. Wavelength, toward the bottom of the page on this website. It looks like it goes from the ultraviolet to infrared range: Molecular vibration and absorption of water molecules Maybe you could extrapolate the index of refraction from some sort of forumula like this. I'm not sure this would work for infrared frequencies though? It's just an appoximation.What is the formula to find the absorption coefficients of materials? X=(2Wnk)/c -> n=X(c/2Wk) X=absorption coefficentc=speed of lightW=frequency of light in the vacuumk=attenuation index (also called extinction coefficient) You'd think there'd be a graph of Refraction Index of Water vs. Wavelength out there somewhere.. :esad: Quote Link to comment Share on other sites More sharing options...
max4236 Posted March 15, 2007 Report Share Posted March 15, 2007 Refractive index "Fig 6. Segelstein's values for the complex refractive index of water for wavelengths from 10 nm to 10m" Quote Link to comment Share on other sites More sharing options...
Becca Posted March 15, 2007 Author Report Share Posted March 15, 2007 there are a few graphs but they almost all stop at 700nm which i find quite selfish . that last one is great, thanks. you've all been a big help, i'll take it from here. Quote Link to comment Share on other sites More sharing options...
eric l Posted March 15, 2007 Report Share Posted March 15, 2007 wow, thanks, i never thought of searching in another language. how did you ever think to try that? also didn't you find that the pages were in dutch? oh well, thanks very much. :) :) Well, Dutch is my mother tongue. If I want to check something on Wikipedia, I still start with the Dutch version. (By the way, Wiki is also a good way to find the key-word you need for searching Google in an other language : just type "refractive index" for the English article in your case, and next ask for the French, German, Spanish...) I had planned to search in French andGerman, too, but the Dutch article gave enough information, the essential of which (the data) I translated. If you want a complete translation, it may take a little longer. If you get no data for wavelengths above 700 nm, it is simply because most of the IR is absorbed by water ! Quote Link to comment Share on other sites More sharing options...
mpolyanskiy Posted July 24, 2008 Report Share Posted July 24, 2008 Hi!Try RefractiveIndex.INFO. It contains refractive index of water for the range 0.182~1.129 microns Quote Link to comment Share on other sites More sharing options...
johnfp Posted August 6, 2008 Report Share Posted August 6, 2008 Check out this site, it has usable calculators for such things. HyperPhysics Quote Link to comment Share on other sites More sharing options...
freeztar Posted August 6, 2008 Report Share Posted August 6, 2008 Check out this site, it has usable calculators for such things. HyperPhysics This link takes you directly to the calculator for Snell's Law:Refraction of Light Quote Link to comment Share on other sites More sharing options...
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