RF and microwave receivers based on electro-optic optical whispering gallery mode resonators

• US 20090097516A1
• Filed: 10/14/2008
• Published: 04/16/2009
• Est. Priority Date: 06/13/2007
• Status: Active Grant

• Current Assignee: Oewaves Incorporated
• Original Assignee: Oewaves Incorporated
• Inventors: Ilchenko, Vladimir, Seidel, David, Maleki, Lutfollah
• Granted Patent: US 7,965,745 B2
• Time in Patent Office: Days
• US Class Current: 372/26
• CPC Class Codes: H01S 5/0608 controlled by light, e.g. optical switch
• CPC Class Codes: H01S 5/065 Mode locking; Mode suppression; Mode selection ; Self pulsating
• CPC Class Codes: H01S 5/0656 Seeding, i.e. an additional light input is provided for controlling the laser modes, for example by back-reflecting light from an external optical component H01S5/14, H01S5/4062 and H01S5/4006 take precedence
• CPC Class Codes: H03B 17/00 Generation of oscillations using radiation source and detector, e.g. with interposed variable obturator
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes

Abstract

RF receivers based on whispering gallery mode resonators.

Claims

1. An 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 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; 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.

2. 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;

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 RF signal carrying a baseband signal and applies the 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.