OPTICAL FREQUENCY SHIFTER AND OPTICAL MODULATOR USING SAME

摘要

The objective of the present invention is to provide a temperature-independent optical frequency shifter which is of a configuration that can be miniaturized and which generates a subcarrier, as well as, using the same, to provide an all-optical OFDM modulator which is of a small size with low temperature dependence and which is capable of accommodating even a grid of a different optical frequency. A frequency shifter is provided with one input-use optical port, a one-input-two-output optical coupler connected to the same, two Mach-Zender modulator units which are each optically connected to the two outputs, a two-input-two-output optical coupler which is optically connected to each of the outputs, and two output-use optical ports which are optically connected to the outputs, wherein the above-described two Mach-Zender modulator units are characterized in being driven by periodic waveforms which are of the same frequency and which mutually differ in phase by (2p+1)p/2 (p: integer). The invention also provides an optical modulator using the same.