4 ms·

Each of those layers of oxides are "quarter wave stacks" (from the paper) which means they're somewhere between 200 to 1000 nanometers (depending on the wavelen

Each of those layers of oxides are "quarter wave stacks" (from the paper) which means they're somewhere between 200 to 1000 nanometers (depending on the wavelength of light they want to transmit or reflect). So one of those layers is say, 200 nanometers, you could end up reflecting the visible and transmitting the infrared, which is the opposite of what you want to do.

HCIdivision17 10y ago
True, but when you have an awful lot of layers, you can play some silly buggers with it. Even if you botch a layer, it won't neccesarily ruin the whole thing, since the interference betwen the sets of layers also act as filters. I haven't worked on these sorts of stacks, personally, but I'd be surprised if the whole stack dies because one layer was a bit screwed up (I'd expect a degredation in the efficiency, but not necessarily a total reversal - now ask me what happens if your goal is to tune to neutral color and you make a slight error and then I'll flip sides and say "rainbow"). What I'd really expect is that if you make one layer slightly larger, your process almost certainly making all the repititions of that layer larger too, and now yeah, your bulk properties are just hosed.