Modulation frequency tunable optical oscillator

A modulation frequency tunable optical oscillator, comprising:

• a pair of wavelength couplers for receiving a pump light of a given wavelength;
• a loop mirror having both ports, each of the ports being connected to one end of the pair of wavelength couplers;
• a coupler connected to the loop mirror for outputting light;
• optical amplification optical fibers each connected to the other ends of the pair of wavelength couplers;
• and
• optical fiber grating mirrors each connected to the optical amplification optical fibers,
• wherein light output from the optical amplification optical fibers is reflected by the loop mirror with different reflectivity per wavelength and is input into the optical fiber grating mirrors through the optical amplification optical fibers, and light in a different wavelength region is reflected by the optical fiber grating mirrors, thereby realizing a dual laser mode resonator.