System and method for switching channels using tunable laser diodes

A channel switching system in a wavelength division multiplexing passive optical network (WDM-PON), the system comprising:

• a channel switching unit switching N channels using N light sources, for N>1, each light source including a wavelength tunable laser, wherein the wavelength tunable laser is a distributed Bragg reflector laser diode (DBR-LD) or a sampled grating distributed Bragg reflector laser diode (SGDBR-LD);
• a signal detector detecting the wavelength optical signal of a channel generated by the channel switching unit, transmitted downstream to an optical network unit (ONU), and transmitted upstream to an optical line terminal (OLT);
• and
• a tracer optimizing a signal of the signal detector by monitoring a relative magnitude change between the signals of the signal detector and wavelength optical signals of the light sources and properly changing wavelengths of the light sources and a temperature of a thermo-electric controller if the signal of the signal detector deteriorates.

A channel switching method in a wavelength division multiplexing passive optical network (WDM-PON), the method comprising:

• generating signals on N channels using N light sources, each light source including a wavelength tunable laser, wherein the wavelength tunable laser is a distributed Bragg reflector laser diode (DBR-LD) or a sampled grating distributed Bragg reflector laser diode (SGDBR-LD);
• switching channels by changing the wavelengths of the lasers so that at least one channel of the N channels have the same wavelength;
• time-multiplexing two or more channels of the at least one channel having the same wavelength;
• and
• optimizing a signal of a signal detector by monitoring a relative magnitude change between the signals of the signal detector and wavelength optical signals of the light sources and properly changing wavelengths of the light sources and a temperature of a thermo-electric controller if the signal of the signal detector deteriorates.