# US 8,570,509 B2 · Spectrometry apparatus, detection apparatus, and method for manufacturing spectrometry apparatus

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,570,509 B2
- Document ID: US8570509B2
- Status: Granted
- Kind: B2
- Application number: 13/106,373
- Filed: 2011-05-12
- Published: 2011-11-17
- Granted: 2013-10-29
- Earliest claimed: 2010-05-13
- Assignees: Seiko Epson Corporation
- Applicants: Jun Amako; Kohei Yamada
- Inventors: Jun Amako; Kohei Yamada
- Web page: https://patentgrep.com/patent/US8570509B2

## CPC

- G01J 3/1804: {Plane gratings}
- G01J 3/44: Raman spectrometry; Scattering spectrometry {; Fluorescence spectrometry}
- G02B 5/1857: {using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams}
- G02B 5/1866: {Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials (G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence)}
- G02B 27/4261: {having a diffractive element with major polarization dependent properties}
- G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

A spectrometry apparatus includes a transmissive diffraction grating that transmits incident light. The transmissive diffraction grating has inclined surfaces made of a first dielectric material. The inclined surfaces are arranged so that they are inclined relative to a reference line. When the angle of incidence of light incident on the transmissive diffraction grating is measured with respect to the reference line and defined as an angle α, and the angle of diffraction of diffracted light is measured with respect to the reference line and defined as an angle β, the angle of incidence α is smaller than a Bragg angle θ defined with respect to the inclined surfaces, and the angle of diffraction β is greater than the Bragg angle θ.

## Claims

### Claim 1

A spectrometry apparatus comprising:
a transmissive diffraction grating that transmits incident light having an operating wavelength λ,
wherein the transmissive diffraction grating has inclined surfaces made of a first dielectric material,
the inclined surfaces are inclined relative to a reference line,
if an angle of incidence of light incident on the transmissive diffraction grating with respect to the reference line is defined as an angle α, and an angle of diffraction of diffracted light with respect to the reference line is defined as an angle β:
the angle of incidence α is smaller than a Bragg angle θ defined with respect to the inclined surfaces, and
the angle of diffraction β is greater than the Bragg angle θ,
if an inclination angle of the inclined surfaces with respect to the reference line is deflned as an angle φ:
the inclined surfaces are arranged at a period P/cosφ in a direction perpendicular to the reference line, and
the incident light is linearly polarized parallel to a flat surface perpendicular to the reference line and perpendicular to the direction in which the inclined surfaces are arranged, and
1.0<λ/P<2.0.

### Claim 2 (depends on 1)

The spectrometry apparatus according to claim 1,
wherein
a group of protrusions made of the first dielectric material is formed at the period P/cosφ on a flat surface of a base of the transmissive diffraction grating, the flat surface being perpendicular to the reference line and the group of protrusions arranged along a direction parallel to the flat surface of the base, and
the inclined surfaces inclined relative to the reference line by the angle φ are formed on the group of protrusions.

### Claim 3 (depends on 2)

The spectrometry apparatus according to claim 2,
wherein the inclination angle φ is set so that adjacent protrusions do not overlap with each other in a plan view projected onto the flat surface of the base.

### Claim 4 (depends on 1)

The spectrometry apparatus according to claim 1,
wherein
the transmissive diffraction grating is formed by alternately arranging the first dielectric material and a second dielectric material having a dielectric constant different from that of the first dielectric material at the period P/cosφ on a base having a flat surface perpendicular to the reference line along a direction parallel to the flat surface of the base, and
the inclined surfaces are formed of boundary surfaces between the first dielectric material and the second dielectric material and inclined relative to the reference line by the angle φ.

### Claim 5 (depends on 1)

The spectrometry apparatus according to claim 1,
wherein the inclined surfaces of the transmissive diffraction grating are formed on a first surface of a base on which the incident light is incident and an anti-reflection film is formed on a second surface of the base through which the diffracted light exits.

### Claim 6 (depends on 1)

A detection apparatus comprising:
the spectrometry apparatus according to claim 1;
an optical system that causes scattered light or reflected light from a target to be incident on the spectrometry apparatus at the angle of incidence α smaller than the Bragg angle θ; and
a detector that detects diffracted light from the spectrometry apparatus.

### Claim 7 (depends on 2)

A detection apparatus comprising:
the spectrometry apparatus according to claim 2;
an optical system that causes scattered light or reflected light from a target to be incident on the spectrometry apparatus at the angle of incidence α smaller than the Bragg angle θ; and
a detector that detects diffracted light from the spectrometry apparatus.

### Claim 8 (depends on 3)

A detection apparatus comprising:
the spectrometry apparatus according to claim 3;
an optical system that causes scattered light or reflected light from a target to be incident on the spectrometry apparatus at the angle of incidence α smaller than the Bragg angle θ; and
a detector that detects diffracted light from the spectrometry apparatus.

### Claim 9 (depends on 4)

A detection apparatus comprising:
the spectrometry apparatus according to claim 4;
an optical system that causes scattered light or reflected light from a target to be incident on the spectrometry apparatus at the angle of incidence α smaller than the Bragg angle θ; and
a detector that detects diffracted light from the spectrometry apparatus.

### Claim 10 (depends on 5)

A detection apparatus comprising:
the spectrometry apparatus according to claim 5;
an optical system that causes scattered light or reflected light from a target to be incident on the spectrometry apparatus at the angle of incidence α smaller than the Bragg angle θ; and
a detector that detects diffracted light from the spectrometry apparatus.

### Claim 11 (depends on 1)

A method for manufacturing the spectrometry apparatus according to claim 1, the method comprising:
irradiating a photoresist applied on a base with first laser light and second laser light so that the photoresist undergoes interference exposure;
developing the photoresist having undergone the interference exposure; and
forming a photoresist pattern inclined relative to a normal to a flat surface of the base by the inclination angle φ.

### Claim 12 (depends on 2)

A method for manufacturing the spectrometry apparatus according to claim 2, the method comprising:
irradiating a photoresist applied on the base with first laser light and second laser light so that the photoresist undergoes interference exposure;
developing the photoresist having undergone the interference exposure; and
forming a photoresist pattern inclined relative to a normal to a flat surface of the base by the inclination angle φ.

### Claim 13 (depends on 3)

A method for manufacturing the spectrometry apparatus according to claim 3, the method comprising:
irradiating a photoresist on the base with first laser light and second laser light so that the photoresist undergoes interference exposure;
developing the photoresist having undergone the interference exposure; and
forming a photoresist pattern inclined relative to a normal to a flat surface of the base by the inclination angle φ.

### Claim 14 (depends on 4)

A method for manufacturing the spectrometry apparatus according to claim 4, the method comprising:
irradiating a photoresist applied on the base with first laser light and second laser light so that the photoresist undergoes interference exposure;
developing the photoresist having undergone the interference exposure; and
forming a photoresist pattern inclined relative to a normal to a flat surface of the base by the inclination angle φ.

### Claim 15 (depends on 5)

A method for manufacturing the spectrometry apparatus according to claim 5, the method comprising:
irradiating a photoresist applied on the base with first laser light and second laser light so that the photoresist undergoes interference exposure;
developing the photoresist having undergone the interference exposure; and
forming a photoresist pattern inclined relative to a normal to a flat surface of the base by the inclination angle φ.