A photonic bolometer includes: a photonic chip; a weak thermal link; a thermally-isolated member, and the weak thermal link thermally isolates the thermally-isolated member from the photonic chip; a photonic temperature sensor; a chip waveguide in optical communication with the photonic temperature sensor; and a photon absorber that receives incident radiation light, increases temperature due to absorption of the incident radiation light, heats the photonic temperature sensor in response to receipt of the incident radiation light, and changes the resonance frequency of the photonic temperature sensor in response to receiving the incident radiation light.