# US 2017/0288688 A1 · Quantum interference device, atomic oscillator, electronic apparatus, and moving object

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- Number: US 2017/0288688 A1
- Document ID: US20170288688A1
- Status: Published application
- Kind: A1
- Application number: 15/465,931
- Filed: 2017-03-22
- Published: 2017-10-05
- Earliest claimed: 2016-03-29
- Assignees: Seiko Epson Corporation
- Applicants: Seiko Epson Corporation
- Inventors: Yoshiyuki MAKI; Nobuhito HAYASHI
- Web page: https://patentgrep.com/patent/US20170288688A1

## CPC

- H03L 7/26: using energy levels of molecules, atoms, or subatomic particles as a frequency reference
- G04F 5/14: using atomic clocks
- H01S 5/005: {Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping (H01S5/026, H01S5/18388 take precedence)}
- H01S 5/183: having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
- H03B 17/00: Generation of oscillations using radiation source and detector, e.g. with interposed variable obturator
- H03L 1/04: Constructional details for maintaining temperature constant
- H01S 5/02212: Can-type, e.g. TO-CAN housings with emission along or parallel to symmetry axis
- H01S 5/02325: Mechanically integrated components on mount members or optical micro-benches
- H01S 5/0687: Stabilising the frequency of the laser
- H03L: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES (generation of oscillations H03B)
- G04F: TIME-INTERVAL MEASURING (measuring pulse characteristics G01R, e.g. G01R29/02; in radar or like systems G01S)
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H03B: GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS (generators adapted for electrophonic musical instruments G10H; masers or lasers H01S; generation of oscillations in plasma H05H)

## Abstract

A quantum interference device includes an atomic cell, a light source, a light detector, a package, and a reflective portion. The atomic cell has alkali metal atoms disposed within, and the light source emits light to excite the alkali metal atoms in the atomic cell. The light detector detects light transmitted through the atomic cell. The package defines an internal space and houses at least the light source. The reflective portion is provided between an inner surface of the package and the light source, and has reflectance to an electromagnetic wave having a wavelength of 4 μm, where the reflectance is greater than or equal to 50%.

## Claims

### Claim 1

A quantum interference device comprising:
an atomic cell that has alkali metal atoms disposed therewithin;
a light source that emits light for exciting the alkali metal atoms in the atomic cell;
a light detector that detects the light transmitted through the atomic cell;
a package that defines an internal space and houses at least the light source; and
a reflective portion provided between an inner surface of the package and the light source, and that has reflectance to an electromagnetic wave having a wavelength of 4 μm, wherein the reflectance of the reflective portion is greater than or equal to 50%.

### Claim 2 (depends on 1)

The quantum interference device according to claim 1, wherein the reflective portion is provided on an outer surface of the light source.

### Claim 3 (depends on 1)

The quantum interference device according to claim 1, wherein the reflective portion is provided on the inner surface of the package.

### Claim 4 (depends on 1)

The quantum interference device according to claim 1, wherein the reflective portion is provided on a side of the light source from which the light is emitted.

### Claim 5 (depends on 1)

The quantum interference device according to claim 1, further comprising:
a support portion that supports the light source,
wherein the reflective portion is provided on a side of the support portion that has the light source.

### Claim 6 (depends on 1)

The quantum interference device according to claim 1, wherein a pressure of the internal space is lower than atmospheric pressure.

### Claim 7 (depends on 1)

The quantum interference device according to claim 1, further comprising:
a support member that supports the atomic cell and the light source with respect to the package,
wherein the thermal conductivity of the support member is equal to or greater than 0.1 W·m−1·K−1 and equal to or less than 40.0 W·m−1·K−1.

### Claim 8 (depends on 1)

An atomic oscillator comprising:
the quantum interference device according to claim 1.

### Claim 9 (depends on 1)

An electronic apparatus comprising:
the quantum interference device according to claim 1.

### Claim 10 (depends on 1)

A moving object comprising:
the quantum interference device according to claim 1.