OPTICAL SPACE TRANSMISSION EQUIPMENT

摘要

PURPOSE: To accurately receive a signal by always fixing optical intensity on a light receiving element in an optical space transmission equipment. CONSTITUTION: A liquid crystal device 8 is arranged between a deflection beam splitter and a lens 4 and incident light L2 is converged on the light receiving element 7 by reducing its optical intensity through the device 8. Liquid crystal for the device 8 consists of ferroelectric liquid crystal excellent in high speed response, particulates each of which has an about 3O0nm diameter are added to the ferroelectric liquid crystal and the device 8 is constituted so that its contrast is continuously changed by impressed voltage. A control signal for the device 8 is formed by an output from the element 7 and reference voltage V1 and the device 8 is driven through a liquid crystal control circuit 23 to always fix optical power to be converged on the element 7.