ÜBERTRAGUNGSSYSTEM MIT VONEINANDER UNABHÄNGIGEN OPTISCHEN ÜBERTRAGUNGSSTRECKEN

摘要

The transmission paths (I-III) operate at different wavelengths (lambda 1-lambda 3). The first path connects a transmitter (1) with a control unit (11) and LEDs (12) to a receiver (2) with photodiodes (21) and an amplifying and processing unit (22). Ahead of the photodiodes a semiconductor filter chip (23) absorbs all wavelengths shorter than the operating wavelength (lambda 1) of that path. The other two paths (II,III) are identically constituted and their wavelengths are longer than that of the first path, in uniform progression. The first two filters (23,43) are of GaAs and Si respectively, while the third (63) is of a ternary or quaternary semiconductor.