Spectrometer for color spectrally-encoded endoscopy

Patent metadata

Field	Value
Publication number	US-10506922-B2
Application number	US-201815947477-A
Country	US
Kind code	B2
Filing date	Apr 6, 2018
Priority date	Apr 6, 2018
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

A grating element has an interface configured to cause light beams, include N visible color lights, incident to the interface to diffract at different orders. An imaging lens is configured to focus the N visible color lights diffracted by the grating element. A sensor is configured to receive and detect the focused N visible color lights. The focused N visible color lights include at least a first color light and a second color light. The first color light is diffracted in a first diffraction order and corresponds to a first wavelength resolution for the first color light. The second color light is diffracted in a second diffraction order and corresponds to a second wavelength resolution for the second color light. The first diffraction order is higher than the second diffraction order and the first wavelength resolution is smaller than the second wavelength resolution.

First claim

What is claimed is:

1. A spectrometer apparatus comprising:
a grating element having an interface configured to cause light beams incident to the interface to diffract in different orders, the light beams including N visible color lights where N is an integer equal to or greater than 2;
an imaging lens configured to focus the N visible color lights diffracted by the grating element, the focused N visible color lights including at least a first color light and a second color light, the first color light being diffracted in a first diffraction order and corresponding to a first wavelength resolution for the first color light, the second color light being diffracted in a second diffraction order and corresponding to a second wavelength resolution for the second color light; and
a sensor configured to receive and detect the N visible color lights focused by the imaging lens,
wherein the first diffraction order is higher than the second diffraction order and the first wavelength resolution is smaller than the second wavelength resolution.

2. The apparatus according to claim 1 , wherein the first color light is a blue light and the second color light is a red light.

3. The apparatus according to claim 1 , wherein the focused N visible color lights further include a third color light having a third diffraction order which is equal to or higher than the second diffraction order.

4. The apparatus according to claim 3 , wherein the first color light is a blue light, the second color light is a red light, and the third color light is a green light.

5. The apparatus according to claim 1 , wherein the first diffraction order is −2 nd order and the second diffraction order is −1 st order.

6. The apparatus according to claim 1 , wherein the first color light has a wavelength band which includes one wavelength from 408 nm to 468 nm and the second color light has a wavelength band which includes one wavelength from 680 nm to 780 nm.

7. The apparatus according to claim 1 , wherein the third color light has a wavelength band which includes one wavelength from 510 nm to 580 nm.

8. The apparatus according to claim 1 , wherein the grating element has binary grating, blazed grating, or holographic grating.

9. The apparatus according to claim 1 , wherein the grating element is of a transmission or reflection type.

10. The apparatus according to claim 1 , further comprising:
an image analyzer configured to display an image collected from the N visible color lights detected by the sensor.

11. A method to provide high resolution color spectrometer for spectrally-encoded endoscopy (SEE) imaging system, the spectrometer having optical parameters of components configured to perform operations comprising:
causing light beams incident to an interface of a grating element to diffract at different orders, the light beams including N visible color lights where N is an integer equal to or greater than 2;
focusing, by an imaging lens, the N visible color lights diffracted by the grating element, the focused N visible color lights including at least a first color light and a second color light, the first color light being diffracted in a first diffraction order and corresponding to a first wavelength resolution for the first color light, the second color light being diffracted in a second diffraction order and corresponding to a second wavelength resolution for the second color light; and
receiving and detecting, by a sensor, the N visible color lights focused by the imaging lens,
wherein the first diffraction order is higher than the second diffraction order and the first wavelength resolution is smaller than the second wavelength resolution.

12. The method according to claim 11 , wherein the first color light is a blue light and the second color light is a red light.

13. The method according to claim 11 , wherein the focused N visible color lights further include a third color light having a third diffraction order which is equal to or higher than the second diffraction order.

14. The method according to claim 13 , wherein the first color light is a blue light, the second color light is a red light, and the third color light is a green light.

15. The method according to claim 11 , wherein the first diffraction order is −2 nd order and the second diffraction order is −1 st order.

16. The method according to claim 11 , wherein the first color light has a wavelength band which includes one wavelength from 408 nm to 468 nm and the second color light has a wavelength band which includes one wavelength from 680 nm to 780 nm.

17. The method according to claim 11 , wherein the third color light has a wavelength band which includes one wavelength from 510 nm to 580 nm.

18. The method according to claim 11 , wherein the grating element has binary grating, blazed grating, or holographic grating.

19. The method according to claim 11 , wherein the grating element is of a transmissive or reflective type.

20. The method according to claim 11 , wherein the optical parameters include at least one of a focal length of the imaging lens, a groove density of the grating element, a diameter of an input fiber core as guiding element for the light source of the incident light beams, and an incident angle on the grating element.

21. A system comprising:
a light source that generates light beams; and
a spectrometer subsystem to image high resolution color lights from the light beams, the spectrometer subsystem comprising:
a collimation lens configured to collimate the light beams;
a grating element having an interface configured to cause the light beams incident to the interface to diffract at different orders, the light beams including N visible color lights where N is an integer equal to or greater than 2;
an imaging lens configured to focus the N visible color lights diffracted by the grating element, the focused N visible color lights including at least a first color light and a second color light, the first color light being diffracted in a first diffraction order and corresponding to a first wavelength resolution for the first color light, the second color light being diffracted in a second diffraction order and corresponding to a second wavelength resolution for the second color light; and
a sensor configured to receive and detect the N visible color lights focused by the imaging lens,
wherein the first diffraction order is higher than the second diffraction order and the first wavelength resolution is smaller than the second wavelength resolution.

Assignees

• Canon Usa Inc

Inventors

• Ikuta Mitsuhiro

Classifications

• G01J2003/1861

  Transmission gratings · CPC title

• G01J2003/1273

  Order selection · CPC title

• G01J3/36

  Investigating two or more bands of a spectrum by separate detectors · CPC title

• G01J3/2823

  Imaging spectrometer · CPC title

• G01J3/0297

  Constructional arrangements for removing other types of optical noise or for performing calibration · CPC title