The construction of half silvered mirrors

[warfreak131]

Hello guys,

I have a question about the construction of half silvered mirrors. I read that they are created using aluminum vapor (so some sort of vapor deposition process?). And I read that the thickness of the aluminum coating can affect the reflectance and transmittance properties (http://en.wikipedia.org/wiki/File:Image-Metal-reflectance.png).

Now it's been a long time since I've done optics, but if I recall correctly a half silvered mirror will split the beam of light if its coming from a certain direction, but pass the beam if it's coming from a different direction. I could be wrong on this, please let me know.

But my question is, how do you quantify the transmitted intensity of the "passed" beam? Such as coating thickness vs transmittance, etc?

 

[Andy Resnick]

The optics of thin metallic films is simply an extension of thin dielectric films- the dielectric constant is complex. Detailed results are available in, for example, Born and Wolf pp752-758. Some other sources include:

http://people.csail.mit.edu/jaffer/FreeSnell/metallic.html
http://link.springer.com/article/10.1007/BF01687039
http://archive.nbuv.gov.ua/portal/natural/sqo/1998-2009/users/pdf/n3_99/013_399.pdf