Degree of polarization method of measuring the polarization scrambler

摘要

PROBLEM TO BE SOLVED: To conduct accurate measurement of characteristics in the degree of polarization by controlling the temperature of a polarization scrambler to be inspected at a predetermined temperature, and maintaining approximately constant coherent light emergent from a light source with respect to a predetermined wavelength. ;SOLUTION: The wavelength of emergent light from a wavelength-variable light source 12 is set, and a polarization scrambler 11 is fixed at a temperature maintaining device 13. Next, temperature to be maintained is set in a temperature control device 14, and its power source is turned on to bring about an energized state. By a signal from the thermocouple 14a of the temperature maintaining device 13, the temperature maintaining device 13 is raised to the set temperature and heated till stabilized at the set temperature to control temperature. After stabilized at the set temperature, coherent light of a predetermined wavelength is emitted from the wavelength-variable fight source 12, and the degree of polarization of light polarization light with respect to a plurality of voltages in the vicinity of the voltage of a modulating signal to be set by a polarization scrambler driving device 15 is measured to obtain voltage characteristics and to search for a voltage that provides the minimum value of the degree of polarization. Then, with the obtained voltage as a driving voltage, wavelength characteristics are obtained by a device 16 for measuring the degree of polarization.;COPYRIGHT: (C)2000,JPO