A novel optical temperature and pressure sensing system

This novel temperature and pressure sensing system uses a thin-film optical band-pass filter (BPF) on an optical fiber end (BOF: BPF on the fiber end) and dual wavelength push-pull reflectometry (DWPR). The system presents advantages over fiber Bragg grating sensors: it can use the mature optical time domain reflectometer (OTDR) technology instead of expensive wavelength-selective technology; it can probe in a small spot area; and it can be free from the influence of disturbances along the optical fiber or within the measuring system. Moreover, it preserves merits of optical fibers such as low transmission loss and immunity from electromagnetic noise. The presented system has temperature measurement accuracy of better than plusmn0.2degC.