Diamond-based high-stability optical devices for precision frequency and time generation
AssigneeThe Boeing Company
InventorsAnguel Nikolov, John R. Lowell, David K. Mefford, John Dalton Williams
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Abstract
Chip technology for fabricating ultra-low-noise, high-stability optical devices for use in an optical atomic clock system. The proposed chip technology uses diamond material to form stabilized lasers, frequency references, and passive laser cavity structures. By utilizing the exceptional thermal conductivity of diamond and other optical and dielectric properties, a specific temperature range of operation is proposed that allows significant reduction of the total energy required to generate and maintain an ultra-stable laser. In each configuration, the diamond-based chip is cooled by a cryogenic cooler containing liquid nitrogen.
Claims17
An optical resonator comprising:
- a spacer made of diamond and having a bore with openings at first and second surfaces of the spacer;
- a first mirror substrate made of diamond having a first portion of a surface fusion bonded to the first surface of the spacer;
- a second mirror substrate made of diamond having a first portion of a surface fusion bonded to the second surface of the spacer;
- a first mirror deposited on a second portion of the surface of the first mirror substrate and positioned to cover the opening in the first surface of the spacer;
- and
- a second mirror deposited on a second portion of the surface of the second mirror substrate and positioned to cover the opening in the second surface of the spacer,
- wherein the first and second mirrors are partially transmissive and parallel to each other to form a high-finesse Fabry-Pérot interferometer.
An optical device comprising:
- a cryogenic cooler configured to have an operating temperature in a range of 40 to 100° K;
- a laser which is controllable to emit light having a specified frequency and specified optical power;
- a diamond chip formed by chemical vapor deposition of diamond crystals, thermally coupled to the cryogenic cooler, optically coupled to receive light from the laser when the laser is activated, and configured to output an optical signal representing an error;
- a photoreceiver optically coupled to receive the optical signal representing the error from the diamond chip when the laser is activated and configured to output an electrical signal representing the error;
- and
- an electronic servo controller configured to stabilize the laser in terms of frequency and phase noise reduction based, at least in part, on the electrical signal representing the error received from the photoreceiver;
- wherein the diamond chip has a bore with mutually opposing ends, further comprising a first partially transmissive mirror disposed at one end of the bore and a second partially transmissive mirror disposed at another end of the bore, wherein the first and second mirrors are parallel to each other and form a high-finesse Fabry-Pérot interferometer;
- and
- wherein the diamond chip comprises:
- a spacer made of diamond crystals and having the bore with openings at first and second surfaces of the spacer;
- a first mirror substrate made of diamond crystals having a first portion of a surface fusion bonded to the first surface of the spacer and having the first mirror deposited on a second portion of the surface;
- and
- a second mirror substrate made of diamond crystals having a first portion of a surface fusion bonded to the second surface of the spacer and having the second mirror deposited on a second portion of the surface.
A method for operating a laser beam with reduced frequency linewidth, the method comprising:
- fabricating a high-finesse Fabry-Pérot interferometer comprising a spacer made of diamond bonded to first and second mirror substrates made of diamond;
- cooling the Fabry-Pérot interferometer to a temperature in a range of 40 to 100° K;
- emitting, from a laser, light having a linewidth;
- guiding the light into the Fabry-Pérot interferometer;
- outputting an optical signal representing an error from the Fabry-Pérot interferometer;
- converting the optical signal representing the error into an electrical signal representing the error;
- and
- stabilizing the laser in terms of frequency and phase noise reduction based, at least in part, on the electrical signal representing the error.
Dependencies are inferred from the claim text.