Methods and apparatus for optical path length equalization in an optical cavity

An optical receiver comprising:

• an optical resonator assembly including at least one optical resonator configured to receive an input optical signal and including a material having an index of refraction that varies as a function of an angle of propagation of light within the material, the material selected to provide a constant optical path length through an optical cavity over a range of angles of incidence of the light on a first semi-reflective surface of the optical cavity;
• and
• a detector configured to detect an intensity modulated output optical signal produced by the at least one optical resonator and to identify a modulation of the input optical signal based at least in part on an intensity modulation of the output optical signal;
• wherein the at least one optical resonator is configured to accumulate resonant optical signal energy inside the at least one optical resonator based at least in part on the input optical signal, and to produce the intensity modulated output optical signal, the intensity modulation of the output optical signal being representative of a modulation of the input optical signal, the at least one optical resonator being configured to maintain a selected resonant condition of the at least one optical resonator over the range of angles of incidence of the input optical signal at the at least one optical resonator.

A method comprising the acts of:

• receiving an input optical signal at an input of at least one optical resonator having a material interposed between first and second semi-reflective surfaces of the optical resonator, the material having an index of refraction that varies as a function of an angle of propagation of light within the material;
• accumulating a resonant condition with the at least one optical resonator based at least in part on the input optical signal to produce an intensity modulated output optical signal, an intensity modulation of the output optical signal being representative of a modulation of the input optical signal;
• and
• maintaining the resonant condition of the at least one optical resonator over a range of angles of incidence of the input optical signal at the at least one optical resonator by providing a constant optical path length through an optical cavity over the range of angles of incidence of the light on the first semi-reflective surface.