Abstract: A system for measuring a chromatic dispersion of an optical fiber based on a baseband phase comparison method has an optical signal transmitter, a reference optical fiber, a measurement optical fiber, and an optical signal receiver. The transmitter has n light sources for selectively generating, as measurement optical signals, optical signals having wavelengths corresponding to n wavelength points to be measured. One of the n light sources also serves to generate a reference optical signal. The transmitter further has an optical switch. The optical switch has n optical signal inputs arranged in correspondence with the n light sources, a measurement optical signal output, and a reference optical signal output. The optical switch commonly outputs, to the measurement optical signal output, the measurement optical signal which is output from the designated one of the n light sources and is selectively input to the n optical signal inputs.

Abstract: A radio wave power measuring apparatus is disclosed, which includes a thel load confined in a reference temperature housing, a wave absorber disposed in the load for absorbing radio waves supplied thereto, a heater for heating the load, a thermoelectric cooler element provided between the housing and the load for the load, a temperature difference detector having a thermoelectric sensor element provided between the housing and the load for detecting the difference in temperature between the housing and the load, a heater controller for feeding to the heater the power corresponding to the temperature difference detected by the detector so as to maintain the load and the housing at the same temperature, and a measuring member for measuring the power fed to the heater.