Spectrometer and spectrum measurement method utilizing same

Patent metadata

Field	Value
Publication number	US-10908019-B2
Application number	US-201716069241-A
Country	US
Kind code	B2
Filing date	Jul 31, 2017
Priority date	Aug 22, 2016
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

Present invention provides a spectrometer including a first unit spectral filter configured to absorb or reflect light in a part of a wavelength band of a light spectrum of an incident target, a second unit spectral filter configured to absorb or reflect light in a wavelength band different from the part of the wavelength band, a first light detector configured to detect a first light spectrum passing through the first unit spectral filter, a second light detector configured to detect a second light spectrum passing through the second unit spectral filter, and a processing unit configured to perform a function of restoring a light spectrum of the target incident from spectra of light detected from the first light detector and the second light detector.

First claim

The invention claimed is:

1. A spectrometer comprising:
a first unit spectral filter including a nano-disk array structure configured to absorb or reflect light in a part of a wavelength band of a light spectrum of an incident target;
a second unit spectral filter including a nano-disk array structure configured to absorb or reflect light in a wavelength band different from the part of the wavelength band;
a first light detector configured to detect a first light spectrum passing through the first unit spectral filter;
a second light detector configured to detect a second light spectrum passing through the second unit spectral filter; and
a processing unit configured to perform a function of restoring a light spectrum of the target incident from spectra of light detected from the first light detector and the second light detector,
wherein the first unit spectral filter and the second unit spectral filter each have a duty cycle between 30% and 80%,
wherein the first unit spectral filter and the second unit spectral filter are configured to form stop band filters by coupling with localized surface plasmons and to pass the light with an intensity distribution as a reverse dip curve to the first light detector and the second light detector.

2. The spectrometer of claim 1 , wherein the nano-disk array structure of the first unit spectral filter and the nano-disk array structure of the second unit spectral filter comprise periodically arranged metal patterns with a predetermined shape.

3. The spectrometer of claim 2 , wherein the metal patterns of the first unit spectral filter and the metal patterns of the second unit spectral filter have different periods.

4. The spectrometer of claim 2 , wherein the first light detector and the second light detector each comprise at least one light detection pixel of a CMOS image sensor.

5. The spectrometer of claim 2 , wherein the metal patterns are composed of a material selected from the group consisting of Au, Ag, Al, Cu, or an alloy containing at least one thereof.

6. The spectrometer of claim 2 , wherein the metal patterns are composed of at least one selected from the group consisting of Cr, Ni, Ti, Pt, Sn, Sb, Mo, W, V, Ta, Te, Ge, and Si, whose light absorption rate and refractive index are high in a visible light and near-infrared band, or an alloy containing at least one thereof.

7. The spectrometer of claim 2 , wherein the metal patterns are composed of at least one selected from the group consisting of Ta, W, Mo, Ni, Cr, TiN, and TiON, whose optical behaviors in a mid-infrared band follow the Drude free electronic model.

8. The spectrometer of claim 2 , wherein the nano-disk array structures are composed of at least a double layer and laminate a low loss high reflectivity metal material and a light absorbing metal material.

9. The spectrometer of claim 8 , wherein the low loss high reflectivity metal material is selected from among Ag, Au, Al, Mg, and an alloy thereof, and the light absorbing metal material comprises at least one of Cr, Ni, Ti, Pt, Sn, Sb, Mo, W, V, Ta, Te, Ge, and Si, an alloy thereof, and silicide, carbide, nitride, or sulfide containing these metals.

10. The spectrometer of claim 2 , wherein the metal patterns of the first unit spectral filter and the metal patterns of the second unit spectral filter have the same duty cycle.

11. The spectrometer of claim 2 , wherein a period of the metal patterns of the first unit spectral filter and the second unit spectral filter is between 100 nm and 800 nm.

12. The spectrometer of claim 2 , wherein the first unit spectral filter and the second unit spectral filter further comprise a passivation layer, and the passivation layer is composed of a material selected from HfO 2 , ZrO 2 , ZnO, ZnSe, TiO 2 , Al 2 O 3 , SiO x , SOG, or an alloy containing at least thereof.

13. The spectrometer of claim 2 , wherein the first unit spectral filter and the second unit spectral filter further comprise a protective layer.

14. The spectrometer of claim 13 , wherein the protective layer is a silicon oxide, a silicon nitride layer, a magnesium fluoride, a calcium fluoride, a low molecular resin, or a polymer material having a low refractive index.

15. The spectrometer of claim 1 , wherein the processing unit is configured to calculate an intensity of light absorbed or reflected by the first unit spectral filter from a spectrum of light of the first light detector;
calculate an intensity of light absorbed or reflected by the second unit spectral filter from a spectrum of light of the second light detector; and
restore a light spectrum of the incident target from the intensity of the light absorbed or reflected by the first unit spectral filter and the second unit spectral filter.

16. A spectrum measurement method using a spectrometer, the method comprising:
entering, by a light spectrum of a target, into first and second unit spectral filters, the first and second unit spectral filters each having a nano-disk array structure with a duty cycle between 30% and 80%;
absorbing or reflecting light in a part of a wavelength band by coupling with a localized plasmon to form a stop band filter by the first unit spectral filter, and absorbing or reflecting light in a wavelength band different from the part of the wavelength band by coupling with a localized plasmon to form a stop band filter by the second unit spectral filter;
detecting, by a first light detector, a first light spectrum passing through the first unit spectral filter in a reverse dip curve distribution and detecting, by a second light detector, a second light spectrum passing through the second unit spectral filter in a reverse dip curve distribution; and
reconstructing a light spectrum of the target incident from the spectra of the light detected from the first light detector and the second light detector.

17. The method of claim 16 , wherein the reconstructing of the light spectrum of the target comprises:
calculating an intensity of light absorbed or reflected by the first unit spectral filter from a first light spectrum of the first light detector;
calculating an intensity of light absorbed or reflected by the second unit spectral filter from a second light spectrum of the second light detector; and
restoring a spectrum of an incident light from the intensity of the light absorbed or reflected by the first unit spectral filter and the second unit spectral filter.

18. The method of claim 17 , wherein the reconstructing of the light spectrum of the target uses a direct readout or regularization technique.

19. The method of claim 17 , wherein the reconstructing of the light spectrum of the target is performed by substituting information on a transmission spectrum f i (λ) of an individual filter and a spectral sensitivity function d i (λ) of a light detector to an equation below and using a measured detection signal r i ,

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Assignees

• Samsung Electronics Co Ltd
• Samsung Electrionics Co Ltd

Inventors

• Lee Kyeong Seok
• Kim Won Mok
• Hwang Gyu Weon
• Kim In Ho
• Lee Wook Seong
• Jeong Doo Seok

Classifications

• G02B6/29389

  Bandpass filtering, e.g. 1x1 device rejecting or passing certain wavelengths (G02B6/2938 takes precedence) · CPC title

• G01N2021/3595

  using FTIR · CPC title

• G01N21/359

  using near infrared light · CPC title

• G01J3/2803 Primary

  using photoelectric array detector · CPC title

• G01J3/08 Primary

  Beam switching arrangements · CPC title