| 摘要 |
PURPOSE:To improve the signal/noise ratio of a detector, by preventing the input of excessive noise to a detection system. CONSTITUTION:Other than bias electrodes 1, 2, voltage measuring electrodes 8, 9 separated from said electrodes 1, 2 and provided to the end part in the light receiving part in the vicinity of said electrodes 1, 2 are mounted and light blocking films 7 are provided to the region between the electrodes 1, 8 and the region between the electrodes 2, 9 through an anodic oxidation film 5 and an insulating film 6 transparent to infrared rays. By this structure, excessive minority carriers generated in the light receiving part 3 by the radiation of infrared rays are drifted and diffused by the electric field applied to the electrodes 1, 2 and also present under the film 7. Further, as the result of thermal excitation, minority of carriers held to a thermal equilibrium state are also generated at the certain points of a crystal 4. By the formation of two kinds of minority carriers and the recombination of said carriers with majority carriers, formed/recombined noise is generated in the crystal 4. Therefore, by amplifying the voltage between the electrodes 8, 9 in place of the electrodes 1, 2, the formed/recombined noise generated under the film 7 not contributing to optical response is avoided to enhance a signal/noise ratio. |
