Are There Wavelength Dependent Mirrots?

Would anyone know if any mirrors (1ft by 0.5ft) exist which are transparent to the visible spectrum yet reflective (anything greater than 30-40% efficiency would be fantastic) to infrared light within a few 100nm above 800nm? I understand that a Bragg mirror would fit the bill however it seems that cost would be prohibitive for such a size, in addition the efficiency far exceeds minimum requirements. I understand also that glass and plexiglass are opaque (in the infrared spectrum) to a certain extent so would it be possible to layer or coat sheets to achieve the desired effect?Thanks very much for any assistance!
- Riley (age 20)
Melbourne, ACT, Australia

What you're looking for is a big version of what's called a "hot mirror". () An indium-tin oxide coating can work well for that. () I don't know whether it's easy to find at a reasonable price, but maybe those key words will help you search. 

Mike W.

(published on 01/17/2016)