Multiwavelength locking method and apparatus using acousto-optic tunable filter

A multiwavelength locking method using an acousto-optic tunable filter being connected to output terminals of N light sources and outputting beams of N different wavelengths outputted from the light sources in the form of an output beam having N frequencies, the multiwavelength locking method comprising the steps of:

• (A) applying the output beam having the N frequencies outputted from a multiplexer and N pilot signals to an acousto-optic tunable filter;
• (B) splitting an output beam outputted from the acousto-optic tunable filter, the output beam having the N frequencies, into two beams, detecting an intensity signal from a first one of the split beams, and detecting a wavelength signal and an intensity signal from a second one of the split beams;
• (C) detecting intensity signals of the first beam respectively corresponding to the N frequencies, and detecting intensity signals and wavelength signals of the second beam respectively corresponding to the N frequencies;
• and
• (D) detecting wavelength signals respectively corresponding to the light sources on the basis of the intensity signals of the first beam and the intensity signals and the wavelength signals of the second beam according to the N frequencies, comparing each of the detected wavelength signals with each of wavelength signals of the beams outputted from the light sources, and compensating for a difference between the compared wavelength signals.