Expandable wavelength division multiplexed optical communications systems

An expandable wavelength division multiplexed optical communication system having at least N wavelengths, where N is a whole number greater than or equal to 2, the wavelength division multiplexed optical communication system comprising:

• N source lasers for producing N optical channels, each channel having a unique wavelength;
• an optical multiplexer module optically communicating with each of the N source lasers for optically combining the N optical channels to form a wavelength division multiplexed optical signal;
• an optical transmission path optically communicating with the optical multiplexer module for carrying the wavelength division multiplexed optical signal;
• a plurality of separately packaged optical channel selecting modules, each selecting module including at least one Bragg grating configured to select a unique optical channel wavelength;
• an optical splitter module for receiving the wavelength division multiplexed optical signal and outputting portions of the wavelength division multiplexed optical signal onto plural output ports, the optical splitter module optically communicating with the optical transmission path and the optical channel selecting modules and having N+y output ports, where y is a whole number greater than or equal to 1, the N+y output ports being configured such that each of the N output ports are optically coupled to one of the Bragg gratings and the y output ports are supplemental ports not optically coupled to the Bragg gratings.

A method for increasing the number of channels in a wavelength division multiplexed optical communication system comprising:

• providing a wavelength division multiplexed optical communication system having a capacity of N wavelengths, where N is a whole number greater than or equal to 2, the wavelength division multiplexed optical communication system comprising:
• N source lasers for producing N optical channels, each channel having a distinct wavelength;
• an optical multiplexer module optically communicating with each of the N source lasers for optically combining the N optical channels to form a wavelength division multiplexed optical signal comprised of N optical channels, the optical multiplexer having N+x inputs, where x is a whole number greater than or equal to 1;
• an optical transmission path optically communicating with the optical multiplexer for carrying the wavelength division multiplexed optical signal;
• an optical splitter module for receiving the wavelength division multiplexed optical signal and outputting portions of the wavelength division multiplexed optical signal onto plural outputs, the optical splitter module optically communicating with the optical transmission path and having N+y outputs, where y is a whole number greater than or equal to 1;
• N optical selecting modules optically communicating with the splitter module, each selecting module including a Bragg grating configured to select a particular channel wavelength;
• providing an (N+1).sup.th source laser to the wavelength division multiplexed optical communication system such that source laser produces an (N+1).sup.th optical channel which optically communicates with the optical splitter, the (N+1).sup.th optical channel being combined with said wavelength division multiplexed optical signal comprised of N optical channels;
• and
• providing an (N+1).sup.th optical selecting module optically including a Bragg grating configured to select the (N+1).sup.th optical channel.