| 摘要 |
PROBLEM TO BE SOLVED: To improve the likelihood ratio, stability, set resolution and variable range of frequencies by obtaining the orthogonal phase heterodyne signals from the output light and sidebands of a wavelength variable light source by using two photodetectors and controlling the frequency of the output light. SOLUTION: The frequency variable light source apparatus consists of a frequency reference light source 1, a sideband generating means 2, the wavelength variable light source 3, an optical heterodyne image removing receiver (optical IRM) 4, a comparing means 5 and a control section 6. The sideband generating means 2 is inputted with the output light of the frequency reference light source 1 as input light and generates the many sidebands of the known frequencies. The optical IRM 4 receives the output of the sideband generating means 2 and part of the output light of the wavelength variable light source 3 and outputs the two heterodyne signals varying in phase by 90 deg. from each other. The comparing means 5 outputs the control signal to the wavelength variable light source 3 in such a manner that the frequencies of the heterodyne signals attain the prescribed offset frequencies including codes in accordance with the orthogonal phase heterodyne signals from the optical IRM 4. |
