Resonantly-Enhanced Optical Phase Detection of RF Signals in LiNBO3

A method detecting a phase difference between a first RF signal having a first phase and a second RF signal having a second phase, said method comprising:

• providing an optical input signal to an optical waveguide comprising an optical input, an optical output and an optical transmission portion separating the optical input from the optical output, the optical input being arranged to receive the optical input signal;
• receiving, via a first RF receiver arranged at a first location, the first RF signal;
• affecting, via the received first RF signal at the first RF receiver, a first non-linear electro-optical material of a first optical resonant cavity;
• receiving, via a second RF receiver arranged at a second location, the second RF signal;
• affecting, via the received second RF signal at the second RF receiver, a second non-linear electro-optical material of a second optical resonant cavity;
• outputting, via the optical output, an optical output signal based on the optical input signal as modified by the first optical resonant cavity as affected by the first RF receiver receiving the first RF signal and as modified by the second optical resonant cavity as affected by the second RF receiver,
• wherein a difference between the optical output signal and the optical input signal is based on a difference between the first phase and the second phase, and
• wherein a difference between the first phase and the second phase is based on a difference between the first location and the second location.

A system for use with a first optical input signal, a second optical input signal and a third optical input signal for detecting a phase difference between a first RF signal having a first phase and a second RF signal having a second phase, said system comprising:

• a first optical waveguide comprising a first optical input, a first optical output and a first optical transmission portion separating said first optical input from said first optical output, said first optical input being arranged to receive the first optical input signal;
• a second optical waveguide comprising a second optical input, a second optical output and a second optical transmission portion separating said second optical input from said second optical output, said second optical input being arranged to receive the second optical input signal;
• a third optical waveguide comprising a third optical input, a third optical output and a third optical transmission portion separating said third optical input from said third optical output, said third optical input being arranged to receive the third optical input signal;
• a first optical resonant cavity comprising a first non-linear electro-optical material;
• a first RF receiver arranged at a first location to receive the first RF signal and being operable to affect said first non-linear electro-optical material of said first optical resonant cavity;
• a second optical resonant cavity comprising a second non-linear electro-optical material;
• a second RF receiver arranged at a second location to receive the second RF signal and being operable to affect said second non-linear electro-optical material of said second optical resonant cavity,
• wherein said first optical waveguide is further operable to output a first optical output signal based on the first optical input signal as modified by said first optical resonant cavity as affected by said first RF receiver receiving the first RF signal,
• wherein said second optical waveguide is further operable to output a second optical output signal based on the second optical input signal as modified by said first optical resonant cavity as affected by said first RF receiver receiving the first RF signal and as modified by said second optical resonant cavity as affected by said second RF receiver,
• wherein said third optical waveguide is further operable to output a third optical output signal based on the third optical input signal as modified by said second optical resonant cavity as affected by said second RF receiver receiving the second RF signal,
• wherein a difference between the second optical output signal and the second optical input signal is based on a difference between the first phase and the second phase, and
• wherein a difference between the first phase and the second phase is based on a difference between the first location and the second location.