Optical communication system with multiple fiber monitoring

An optical communication network which comprises:

• a) a fiber-optic terminal system (hereafter, FOTS) situated at a central office or remote terminal, the FOTS adapted for transmitting signals into, or receiving signals from, a multiplicity of optical waveguiding bodies situated within the central office or remote terminal, the signals having one or more signal wavelengths;
• b) means for interconnecting the multiplicity of optical waveguiding bodies with a corresponding multiplicity of optical fibers situated substantially outside of the central office or remote terminal;
• c) means for optically coupling the FOTS to the multiplicity of waveguiding bodies;
• and
• d) an OTDR transmitter for transmitting, into at least some of the optical waveguiding bodies, OTDR signals at one or more monitor wavelengths different from the signal wavelengths;
• CHARACTERIZED IN THAT the optical coupling means comprise:
• e) a substrate body having a substantially planar principal surface, a longitudinal direction defined parallel to the surface, and a normal direction defined perpendicular to the surface;
• f) a multiplicity of longitudinally extending, planar, main optical waveguides formed on the surface, each said main waveguide optically coupled at one end to the FOTS and optically coupled at the other end to one of the waveguiding bodies;
• g) a multiplicity of planar monitor waveguides formed on the surface for transmitting OTDR signals from the OTDR transmitter to at least some of the main waveguides;
• and
• h) a multiplicity of wavelength-division multiplexers formed on the surface, each multiplexer adapted for optically coupling a corresponding monitor waveguide to a corresponding main waveguide with respect to monitor wavelengths but not with respect to signal wavelengths.