| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical phase synchronization device capable of synchronizing an optical phase of local oscillation light to main light source light by feeding back a phase difference between the main light source light and the local oscillation light as an error signal.SOLUTION: A local oscillation light source is configured by a semiconductor laser. A current drive terminal close to a DC and an RF drive terminal are provided to an excitation current terminal of the semiconductor laser. An optical frequency feedback circuit for stabilizing an optical frequency is connected to the current drive terminal. An optical phase feedback circuit to which an error current for a main light source outputted from an optical phase error detector is fed back is connected to the RF drive terminal. The optical frequency feedback circuit is constituted of a feedback circuit detecting an optical frequency error between signal light from the semiconductor laser and reference light, feeding back the optical frequency error signal to a constant current source to add it to a setting current value, and having a relatively narrow loop band. The constant current source of the optical frequency feedback circuit has a high impedance when seen from the RF drive terminal side, and is provided with a frequency divider dividing a light difference frequency between the signal light and the reference light to gently control stabilization of the optical frequency. |
