Abstract: Techniques and devices for measuring phase noise in radio frequency (RF), microwave, or millimeter signals based on photonic delay.

Abstract: In one aspect, this document provides an implementation of a system for characterizing an oscillator. This system includes an input port that receives an oscillation signal from an oscillator under test; an input port signal splitter that splits the received oscillation signal into a first oscillation signal and a second oscillation signal; a first photonic signal processing branch circuit that processes the first oscillation signal to produce a first branch output signal; a second photonic signal processing branch circuit that processes the second oscillation signal to produce a second branch output signal; a dual channel signal analyzer that receives the first and second branch output signals to measure noise in the received oscillation signal; and a computer controller that controls the first and second photonic signal processing branch circuits and the dual channel signal analyzer to control measurements of the noise in the received oscillation signal.

Abstract: Techniques and devices that lock and stabilize a laser to an optical resonator via self-injection locking based on a reflection feedback. A whispering gallery mode optical resonator can be implemented to provide both the optical filtering and injection feedback based on the reflection feedback from feedback optics outside the optical resonator.

Abstract: Techniques and devices based on transverse magnetic (TM) and transverse electric (TE) modes in an optical resonator or interferometer to provide sensitive optical detection with insensitivity to a change in temperature. A shift in a difference between a first resonance wavelength of a TE optical mode and a second resonance wavelength of a TM optical mode is measured to measure a change in a sample that is in optical interaction with the optical resonator or interferometer. For example, the detected shift can be used to measure a change in a refractive index of the sample.

Abstract: Techniques and devices based on optical resonators made of nonlinear optical materials and nonlinear wave mixing to generate RF or microwave oscillations and optical comb signals.

Abstract: Devices having whispering-gallery-mode (WGM) resonators configured to meet requirements of various applications and facilitate fabrication of such devices.

Abstract: Devices and techniques for forming devices based on electro-optic whispering gallery mode (WGM) resonators by using spatially modulated electrodes and electro-optic whispering gallery mode (WGM) resonators that effectuate coupling between light in an optical whispering gallery mode in the TE mode and light in another optical whispering gallery mode in the TM mode.

Abstract: Techniques and devices for tuning a phase shift of an RF or microwave signal by using an optical tuning mechanism based on photonic elements.

Abstract: Optical gyroscope devices based on optical whispering gallery mode resonators that measure rotations based on rotation-induced optical phase shift in optical whispering gallery mode resonators.

Abstract: Techniques and devices that stabilize a laser to a whispering gallery mode optical resonator.

Abstract: Devices and techniques for frequency conversion of radio frequency (RF) or microwave signals based on photonic processing.

Abstract: Among others, RF receivers based on whispering gallery mode resonators are described. In one aspect, a photonic RF device includes a laser that is tunable in response to a control signal and produces a laser beam at a laser frequency. The RF device includes a first optical resonator structured to support a whispering gallery mode circulating in the first optical resonator, the optical resonator being optically coupled to the laser to receive a portion of the laser beam into the optical resonator in the whispering gallery mode and to feed laser light in the whispering gallery mode in the optical resonator back to the laser to stabilize the laser frequency at a frequency of the whispering gallery mode and to reduce a linewidth of the laser. The RF device includes a second optical resonator made of an electro-optic material to support a whispering gallery mode circulating in the optical resonator.

Abstract: Techniques and devices for providing optical locking of optical resonators and lasers.

Abstract: Techniques and devices for measuring phase noise in radio frequency (RF), microwave, or millimeter signals based on photonic delay.

Abstract: Optical resonators and optical devices based on optical resonators that implement diffractive couplers for coupling light with the optical resonators.

Abstract: Techniques and devices for providing optical locking of optical resonators and lasers.

Abstract: RF and microwave devices and techniques are disclosed for processing RF and microwave signals by using (1) photonic or optical components and (2) RF and microwave components. In some implementations, a part of the processing is performed in the RF and microwave domain such as applying a microwave or RF input signal to control an optical modulator, and another part of the processing is performed in the optical domain such as optical filtering of the modulated optical beam to select desired microwave or RF spectral components. The frequency of a selected spectral component can be tuned by either tuning the frequency of the optical beam that is modulated by the optical modulator or a filter that is used to filter modulated optical beam.

Abstract: Examples and implementations of photonic devices and techniques based on whispering gallery mode resonators formed of electro-optic materials to effectuate cross modulation between whispering gallery modes of different polarizations in the resonators.

Abstract: Photonic devices and techniques based on tunable single sideband (SSB) modulation in whispering gallery mode resonators formed of electro-optic materials to effectuate coupling between whispering gallery modes of different polarizations.

Abstract: Tunable receivers and techniques for receiving an electrical oscillator signal in the RF, microwave or millimeter spectral range based on photonics technology to use both (1) photonic or optical components and (2) electronic circuit components.