The present disclosure is directed to a fiber optic bolometer device. In an implementation, a fiber optic bolometer device includes an optical fiber and a silicon layer that comprises a Fabry-Pérot interferometer. The silicon layer includes a first surface and a second surface. The fiber optic bolometer device includes a reflective dielectric film disposed over the first surface of the silicon layer where the reflective dielectric film is adjacent to an end face of the optical fiber. The fiber optic bolometer device also includes an absorptive coating disposed over the second surface of the silicon layer (e.g., the surface distal to the end face of the optical fiber).