Apparatus and method for maintaining wavelength interval of light sources

An apparatus for maintaining a wavelength interval of light sources, comprising:

• a plurality of light sources configured to output light having different wavelengths and having a certain wavelength interval;
• a modulator configured to receive an optical signal in which at least some of the output light of each of the plurality of light sources is combined, and modulate the optical signal to a sine wave of a preset first frequency and output the sine wave;
• a light reception unit configured to receive the optical signal modulated to the sine wave of the first frequency and output an electrical signal including a frequency component corresponding to the certain wavelength interval;
• and
• a controller configured to detect the frequency component corresponding to the certain wavelength interval from the electrical signal and control a wavelength of each of the plurality of light sources to maintain the certain wavelength interval based on the detected frequency component,
• wherein:
• the certain wavelength interval between adjacent light is identical between the plurality of light that the light sources output,
• the light reception unit outputs electrical signals of a first frequency domain and a second frequency domain including the frequency component corresponding to the certain wavelength interval for the received optical signal,
• the controller controls the wavelength of each of the plurality of light sources to maintain the certain wavelength interval based on the frequency component detected from at least one frequency domain of the first frequency domain and the second frequency domain, and
• the controller alternately performs wavelength control of each of the plurality of light sources based on power of the first frequency domain and wavelength control of each of the plurality of light sources based on power of the second frequency domain.

A method of maintaining a wavelength interval of light sources, comprising:

• receiving an electrical signal corresponding to an optical signal in which at least some of output light of each of the plurality of light sources having different wavelengths and having a certain wavelength interval is combined;
• detecting a frequency component corresponding to the certain wavelength interval from the received electrical signal;
• and
• controlling the wavelength of each of the plurality of light sources so that the certain wavelength interval is maintained based on the detected frequency component,
• wherein the certain wavelength interval between adjacent light is identical between the plurality of light that the light sources output,
• wherein the receiving of the electrical signal includes:
• modulating the optical signal in which the at least some of the output light of each of the plurality of light sources is combined to a sine wave of a preset first frequency;
• and
• receiving an electrical signal corresponding to the optical signal modulated to the sine wave of the first frequency,
• wherein:
• the electrical signal corresponding to the optical signal modulated to the sine wave of the first frequency includes a first frequency domain and a second frequency domain including the frequency component corresponding to the certain wavelength interval;
• and
• in the controlling, the wavelength of each of the plurality of light sources is controlled to maintain the certain wavelength interval based on the frequency component detected from at least one frequency domain of the first frequency domain and the second frequency domain,
• wherein in the controlling, wavelength control of each of the plurality of light sources based on power of the first frequency domain and wavelength control of each of the plurality of light sources based on power of the second frequency domain are alternately performed.