An infrared optical field effect transistor has been developed using a thin film of lead titanate (PbTiO3) deposited on a n/p+ Si substrate by rf sputtering, in which the drain conductance changes in proportion to the infrared light power. A fast response with a rise time of 2.3 μs has been obtained that is about 150% faster than the other types of thermal infrared optical field effect transistor. The developed infrared sensor is a bulk channel field effect transistor structure, that possesses higher mobility. Thus, faster speed can be obtained. In addition, the sensor has been prepared on a Si substrate, which offers the potential to develop Si-based infrared optical-electric integrated circuits.