RF and microwave receivers based on electro-optic optical whispering gallery mode resonators
First Claim
1. A photonic RF device, comprising:
- a laser that is tunable in response to a control signal and produces a laser beam at a laser frequency;
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;
a second optical resonator made of an electro-optic material to support a whispering gallery mode circulating in the optical resonator, the second optical resonator being optically coupled to the laser to receive a portion of the laser beam from the laser;
an RF circuit that receives an input RF signal carrying a baseband signal and modulates the second optical resonator at a frequency equal to a free spectral range of the second optical resonator to cause optical modulation in the received portion of the laser beam so the modulated light inside the second optical modulator carries the baseband signal; and
a slow optical detector coupled to detect modulated light coupled out of the second optical resonator to produce a baseband signal of the input RF signal.
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Accused Products
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.
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Citations
10 Claims
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1. A photonic RF device, comprising:
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a laser that is tunable in response to a control signal and produces a laser beam at a laser frequency; 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; a second optical resonator made of an electro-optic material to support a whispering gallery mode circulating in the optical resonator, the second optical resonator being optically coupled to the laser to receive a portion of the laser beam from the laser; an RF circuit that receives an input RF signal carrying a baseband signal and modulates the second optical resonator at a frequency equal to a free spectral range of the second optical resonator to cause optical modulation in the received portion of the laser beam so the modulated light inside the second optical modulator carries the baseband signal; and a slow optical detector coupled to detect modulated light coupled out of the second optical resonator to produce a baseband signal of the input RF signal. - View Dependent Claims (3, 4, 5)
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2. A photonic RF device, comprising:
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a laser that is tunable in response to a control signal and produces a laser beam at a laser frequency; an optical resonator structured to support a whispering gallery mode circulating in the 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 optical resonator exhibiting an electro-optic effect in response to a control signal; electrodes formed on the optical resonator to apply the control signal to the optical resonator; an RF circuit that receives an input RF signal carrying a baseband signal and applies the input RF signal to the electrodes on the optical resonator at a frequency equal to a free spectral range of the optical resonator; a first optical detector coupled to detect modulated light coupled out of the optical resonator to produce a baseband signal of the input RF signal; a second optical detector coupled to detect modulated light coupled out of the optical resonator to produce a feedback signal; and an electrical feedback that applies the feedback signal to the electrodes to perform optical modulation in the optical resonator. - View Dependent Claims (6, 7, 8)
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9. A photonic RF device, comprising:
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a first photonic RF receiver that includes a first RF antenna to receive a first RF signal and to output a first baseband signal carried by the first RF signal; and a second photonic RF receiver that includes a second RF antenna to receive a second RF signal and to output a second baseband signal carried by the second RF signal, where each of the first and second photonic RF receivers includes a laser that is tunable in response to a control signal and produces a laser beam at a laser frequency; an optical resonator structured to support one or more optical whispering gallery modes and exhibiting an electro-optic effect in response to a control signal, the optical resonator being optically coupled to the laser to receive a portion of the laser beam into the optical resonator in a whispering gallery mode and to feed laser light in the whispering gallery mode in the optical resonator back to the laser via injection locking to stabilize the laser frequency at a frequency of the whispering gallery mode; electrodes formed on the optical resonator to apply the control signal, which includes a respective input RF signal, to the optical resonator to cause optical modulation of light confined inside the optical resonator via the electro-optic effect so that the modulated light carries a respective baseband signal in the respective input RF signal; a first optical detector coupled to detect modulated light coupled out of the optical resonator to produce a respective baseband signal of the respective input RF signal; a second optical detector coupled to detect modulated light coupled out of the optical resonator to produce an electrical detector signal; a feedback circuit that receives the electrical detector signal to produce an electrical feedback signal; and a signal combiner that combines the electrical feedback signal from the second optical detector and the respective input RF signal from a respective RF antenna to produce the control signal; wherein the feedback circuit in the first photonic RF receiver and the feedback circuit in the second photonic RF receiver are coupled to each other to combine the control signals in the first and second photonic RF receivers to synchronize the first and second photonic RF receivers. - View Dependent Claims (10)
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Specification