Optical characteristic measuring apparatus, method and recording medium

A method for measuring the characteristics of device under test that transmits light comprising:

• a variable wavelength light generating step for generating a variable wavelength light;
• a wavelength setting step for setting said variable wavelength light at a first wavelength and a second wavelength;
• an initial modulation frequency setting step for setting the initial modulation frequency for modulation;
• a modulating signal generating step for generating a modulating signal of a set modulation frequency;
• an optical modulating step for receiving the input of said modulating signal and modulating said variable wavelength light with the frequency of said modulating signal;
• a phase measuring step for measuring the first phase of said transmitted light, which is obtained by the transmission through the device under test of an incident light having the first wavelength and the second phase of said transmitted light, which is obtained by the transmission through the device under test of an incident light having the second wavelength;
• a modified modulation frequency computing step for computing a modified modulation frequency by multiplying the value, which is obtained by dividing the given phase value by the phase difference between the first phase and the second phase, by said initial modulation frequency;
• and
• a modified modulation frequency setting step for setting said modified modulation frequency as the frequency of said modulating signal,
• wherein the characteristics of device under test are measured on the basis of the transmitted light resulting from the transmission through said device under test of the incident light modulated by a frequency set by said modified modulation frequency setting step.

A computer-readable medium having a program of instructions for execution by the computer to perform a characteristics measuring process for measuring characteristics of device under test that transmits light, said characteristics measuring process comprising:

• a variable wavelength light generating process for generating a variable wavelength light;
• a wavelength setting process for setting said variable wavelength light at a first wavelength and a second wavelength;
• an initial modulation frequency setting process for setting the initial modulation frequency for modulation;
• a modulating signal generating process for generating a modulating signal of a set modulation frequency;
• an optical modulating process for receiving the input of said modulating signal and modulating said variable wavelength light with the frequency of said modulating signal;
• a phase measuring process for measuring the first phase of said transmitted light, which is obtained by the transmission through the device under test of an incident light having the first wavelength and the second phase of said transmitted light, which is obtained by the transmission through the device under test of an incident light having the second wavelength;
• a modified modulation frequency computing process for computing a modified modulation frequency by multiplying the value, which is obtained by dividing the given phase value by the phase difference between the first phase and the second phase, by said initial modulation frequency;
• and
• a modified modulation frequency setting process for setting said modified modulation frequency as the frequency of said modulating signal,
• wherein the characteristics of device under test are measured on the basis of the transmitted light resulting from the transmission through said device under test of the incident light modulated by a frequency set by said modified modulation frequency setting process.