Systems and methods for designing and fabricating carbon nanotube based detectors are disclosed. In some embodiments, one or more sensor elements can be formed from a film of single-walled carbon nanotubes (SWNTs). Bolometric properties of such detectors are disclosed. In some embodiments, the film can be thermally isolated in various ways, such as suspending the film and providing a vacuum environment, to provide the bolometric properties. Various properties of the SWNT films, such as resistivity-dependence on temperature and spectral response, can be obtained by adjusting the dimension and/or composition of the film. Examples of SWNT film formation, detector element fabrication, and array fabrication are disclosed.