Passive Optical Diode on Semiconductor Substrate

A method of fabricating an optical device, comprising:

• forming an optical cavity on the semiconductor substrate, the optical cavity configured to store light;
• forming on the semiconductor substrate a first light guide having an input, the first light guide optically coupled to the optical cavity by a first coupling strength, the first light guide having an input coupling;
• and
• forming on the semiconductor substrate a second light guide having an output coupling, the second light guide optically coupled to the optical cavity by a second coupling strength;
• wherein the second coupling strength is greater than the first coupling strength, and wherein the optical cavity, the first light guide and the second light guide are formed such that a first wavelength of light propagates from the input coupling to the output coupling with a first attenuation, and the first wavelength of light propagates from the output coupling to the input coupling with a second attenuation that is greater than the first attenuation.

A method of using an optical device, comprising:

• receiving an optical signal at a first light guide via a first input coupling, the first light guide coupled to an optical cavity by a first coupling strength, the optical cavity disposed on a semiconductor substrate and configured to store light;
• coupling the optical signal from first light guide to the optical cavity;
• coupled the optical signal from the optical cavity to a second light guide, the second light guide coupled to the optical cavity by a second coupling strength, the second light guide having an output coupling;
• wherein the second coupling strength is greater than the first coupling strength, and wherein the optical device is configured such that a first wavelength of light propagates from the input coupling to the output coupling with a first attention, and the first wavelength of light propagates from the output coupling to the input coupling with a second attenuation that is greater than the first attenuation.