The Magnetic Semiconductor Photodetector (MSP) is a 40-μm-thick transducer with a magnetic semiconductor film that is composed of MnO, ZnO and Fe2O3 and that has a surface painted with a radiant flux absorbent. Incident light increases the MSP temperature, increasing the MSP's magnetic reluctance. The magnetic density variation in the MSP is read out by a Hall element. MSP patterns can be printed on the substrate in various shapes (such as a plate, a ring, or a rod), and the MSP is suitable for use as a photosensor, a photochopper, a photorelay, or an exposure meter. Preparation techniques, pyromagnetic characteristics, and the light signal read out are discussed here.
