Optimizing Sensor Thickness for Efficient Optical Wavelength Detection?

[LightningInAJar]

TL;DR

Space cameras outside of visible spectrum.

When creating sensors to record images from much larger wavelengths of radiation, must the sensor be at least as deep as the wavelength, or is there a way to make it more compact?

 

[Drakkith]

You can make it smaller than the wavelength, but you'll start losing efficiency as you make it smaller. This is why antennas are usually not much smaller than about 1/4 of the wavelength of interest. I assume something similar is true of optical sensor thickness but I can't say for certain.