Wavelength selective reflective/transmissive optical coupler and method

A reflective/transmissive optical coupler comprising:

• first, second and third transmissive coupling elements configured to combine wavelengths, the first and second transmissive coupling elements each having input ports to provide input ports for the optical coupler, and the third transmissive coupling element providing at least one output port for the optical coupler;
• a first wavelength-selective reflective element to reflect a predetermined wavelength from an output of the first transmissive coupling element to inputs of the first transmissive coupling element;
• a second wavelength-selective reflective element to reflect the predetermined wavelength from an output of the second transmissive coupling element to an input of the second transmissive coupling element;
• and
• a wavelength-selective coupling element to transfer the predetermined wavelength between outputs of the first and second transmissive coupling elements and inhibit transmission of other wavelengths between the outputs of the first and second couplers,
• wherein the first transmissive coupling element transfers at least the predetermined wavelength, when received at any one of the input ports of the first transmissive coupling element, to both the first wavelength-selective reflective element and the wavelength selective coupling element, the predetermined wavelength being reflected by the first wavelength-selective reflective element back through the first transmissive coupling element to the input ports of the first transmissive coupling element, the wavelength selective coupling element coupling the predetermined wavelength to the second transmissive coupling element to be provided through the second transmissive coupling element to the input ports of the second transmissive coupling element,
• and wherein the second transmissive coupling element transfers at least the predetermined wavelength, when received at any one of the input ports of the second transmissive coupling element, to both the second wavelength-selective reflective element and the wavelength selective coupling element, the predetermined wavelength being reflected by the second wavelength-selective reflective element back to the input ports of the second transmissive coupling element, the wavelength selective coupling element coupling the predetermined wavelength to the first transmissive coupling element to be provided to the input ports of the transmissive coupling element.

A reflective/transmissive optical coupler comprising:

• first, second and third transmissive coupling elements configured to combine wavelengths;
• a first wavelength-selective reflective element to reflect a predetermined wavelength from an output of the first transmissive coupling element to inputs of the first transmissive coupling element;
• a second wavelength-selective reflective element to reflect the predetermined wavelength from an output of the second transmissive coupling element to an input of the second transmissive coupling element;
• and
• a wavelength-selective coupling element to transfer the predetermined wavelength between outputs of the first and second transmissive coupling elements and inhibit transmission of other wavelengths between the outputs of the first and second couplers,
• wherein the wavelength-selective coupling element transfers the predetermined wavelength from a second output of the second transmissive coupling element to a second output of the first transmissive coupling element, the first transmissive coupling element transferring the predetermined wavelength to the inputs of the first transmissive coupling element when received at the second output, and
• wherein the wavelength-selective coupling element has an input to receive wavelengths from the second transmissive coupling element, a direct output to transfer the other wavelengths and a coupled output to transfer the predetermined wavelength other than the other wavelengths to the first transmissive coupling element,
• and wherein the reflective/transmissive optical coupler further comprises a termination to reduce reflections of the other wavelengths from being reflected back to the direct output of the wavelength-selective coupling element.

A reflective/transmissive optical coupler comprising:

• first, second and third transmissive coupling elements configured to combine wavelengths;
• a first wavelength-selective reflective element to reflect a predetermined wavelength from an output of the first transmissive coupling element to inputs of the first transmissive coupling element;
• a second wavelength-selective reflective element to reflect the predetermined wavelength from an output of the second transmissive coupling element to an input of the second transmissive coupling element;
• and
• a wavelength-selective coupling element to transfer the predetermined wavelength between outputs of the first and second transmissive coupling elements and inhibit transmission of other wavelengths between the outputs of the first and second couplers, and
• wherein at least one of the first and second wavelength reflective elements is a lens having a coating to substantially reflect the predetermined wavelength and to pass substantially the other wavelengths.

A reflective/transmissive optical coupler comprising:

• first, second and third transmissive coupling elements configured to combine wavelengths;
• a first wavelength-selective reflective element to reflect a predetermined wavelength from an output of the first transmissive coupling element to inputs of the first transmissive coupling element;
• a second wavelength-selective reflective element to reflect the predetermined wavelength from an output of the second transmissive coupling element to an input of the second transmissive coupling element;
• a wavelength-selective coupling element to transfer the predetermined wavelength between outputs of the first and second transmissive coupling elements and inhibit transmission of other wavelengths between the outputs of the first and second couplers;
• fourth and fifth transmissive coupling elements;
• a third wavelength-selective reflective element to reflect the predetermined wavelength from an output of the fourth transmissive coupling element back through the fourth transmissive coupling element to inputs of the fourth transmissive coupling element, and to transfer the other wavelengths from the first output of the fourth transmissive coupling element to an input of the third transmissive coupling element;
• a fourth wavelength-selective reflective element to reflect the predetermined wavelength from an output of the fifth transmissive coupling element back through the fifth transmissive coupling element to inputs of the fifth transmissive coupling element, and to transfer the other wavelengths from the first output of the fifth transmissive coupling element to an input of the third transmissive coupling element;
• and
• additional wavelength-selective coupling elements to transfer the predetermined wavelengths between outputs of the transmissive coupling elements and to inhibit transmission of the other wavelengths therebetween.

A method of coupling optical signals comprising:

• transferring signals on wavelengths other than a predetermined wavelength received at any of ports of a first set to a port of a second set, wherein the first set of port includes at least four ports;
• transferring signals on the predetermined wavelength received at any port of the first set to each other port of the first set;
• and
• inhibiting signals on wavelengths other than the predetermined wavelength received at any port of the first set from transmission to the other ports of the first set.