Multiband photonic integrated circuit (PIC) I and Q demodulator

A method comprising:

• modulating a radio frequency (RF) input signal onto a first optical signal;
• modulating a local oscillator (LO) signal onto a second optical signal;
• and
• using a photonic integrated circuit comprising an optical demodulator, generating, based on the first and second modulated optical signals, I and Q signals representing a demodulated version of the RF input signal;
• wherein generating the I and Q signals comprises:
• filtering the first optical signal using a selected one of multiple optical filters;
• filtering the second optical signal;
• altering a phase of the second optical signal relative to the first optical signal;
• combining the filtered first optical signal and the filtered and phase-shifted second optical signal to produce a combined optical signal;
• separating the combined optical signal by wavelength to produce multiple optical signals;
• and
• converting the multiple optical signals into the I and Q signals.

A system comprising:

• a radio frequency (RF) front end configured to obtain an RF input signal;
• a photonic integrated circuit comprising:
• a first modulator configured to modulate the RF input signal onto a first optical signal;
• a second modulator configured to modulate a local oscillator (LO) signal onto a second optical signal;
• and
• an optical demodulator configured to generate, using the first and second modulated optical signals, I and Q signals representing a demodulated version of the RF input signal;
• an analog-to-digital converter configured to convert the I and Q signals into digital values;
• and
• a processor configured to process the digital values,
• wherein the optical demodulator comprises:
• an optical filter bank comprising multiple optical filters, wherein different ones of the optical filters are configured to pass different frequencies or frequency ranges;
• a first optical switch configured to selectively provide the first modulated optical signal to a selected one of the optical filters;
• and
• a second optical switch configured to receive a filtered first optical signal from the selected one of the optical filters.

A method comprising:

• modulating a radio frequency (RF) input signal onto a first optical signal;
• modulating a local oscillator (LO) signal onto a second optical signal;
• and
• using a photonic integrated circuit comprising an optical demodulator, generating, based on the first and second modulated optical signals, I and Q signals representing a demodulated version of the RF input signal,
• wherein generating the I and Q signals comprises:
• using a first optical switch to selectively provide the first modulated optical signal to a selected one of multiple optical filters, wherein different ones of the optical filters are configured to pass different frequencies or frequency ranges;
• filtering the first modulated optical signal using the selected one of the optical filters;
• and
• using a second optical switch to receive a filtered first optical signal from the selected one of the optical filters.