[analog31]

Color visible sensors tend to have a spectral range of 400 to around 1000 nm. (There is often an additional glass filter to block ~ 800+, which is removable).

Beyond 1000 nm, silicon becomes transparent and ceases to work as a detector, so those longer wavelengths need a detector made from another material, notably indium gallium arsenide (InGaAs) which in one form can get all the way out to around 2700 nm. Anything that gets you away from silicon chip fab also gets you away from the fab-ulous economics of silicon. InGaAs sensors are super damn expensive.

Beyond 2700, thermal imaging cameras and the like use even more exotic sensor materials.

An alternative for those longer wavelengths is a monochromator (e.g., rotating diffraction grating detecting one wavelength at a time) and a single element detector which is cheaper than an array. If course your subject has to be sitting still for the duration of your measurement.