CN-122016044-A - Spectrometer for enlarging OCT imaging depth and fusion imaging method

CN122016044ACN 122016044 ACN122016044 ACN 122016044ACN-122016044-A

Abstract

The invention belongs to the technical field of optical coherence tomography, and particularly relates to a spectrometer for enlarging OCT imaging depth and a fusion imaging method. The dichroic mirror is used for receiving incident light entering the spectrometer and dividing the incident light into first emergent light and second emergent light, the first photosensitive element is placed at a position imaged by the first emergent light with the wavelength in a first range and used for imaging the first emergent light with the wavelength in the first range, and the second photosensitive element is placed at a position imaged by the second emergent light with the wavelength in a second range and used for imaging the second emergent light with the wavelength in the second range. The equivalent pixel number obtained by the invention is larger than that of a single camera, so that OCT brings higher spectral resolution under the condition of unchanged spectral range, and larger imaging depth is realized.

Inventors

SONG WEIYE
CUI YUAN
QI MIN
YANG HAOHUA
Yao Zhengkai
Yan Bingcan
LIU ENYU
XU GUODONG
ZHAO YIXIANG
GUAN YANXIN
ZHOU LIBO

Assignees

山东大学

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (15)

1.A spectrometer for expanding the imaging depth of OCT comprising a dichroic mirror, a first photosensitive element, and a second photosensitive element: A dichroic mirror for receiving incident light entering the spectrometer and dividing the incident light into a first outgoing light and a second outgoing light; a first photosensitive element disposed at a position where the first outgoing light having a wavelength in the first range is imaged, for imaging the first outgoing light having a wavelength in the first range; and the second photosensitive element is arranged at a position imaged by the second emergent light with the wavelength in the second range and is used for imaging the second emergent light with the wavelength in the second range.
2. The extended OCT imaging depth spectrometer of claim 1, wherein the first exit light is imaged along a first optical path toward a first photosensitive element and the second exit light is imaged along a second optical path toward a second photosensitive element.
3. The extended OCT imaging depth spectrometer of claim 2, further comprising a first grating and a first lens disposed on the first optical path, wherein: the first grating is used for receiving the first emergent light and diffracting the first emergent light to form diffracted light of the first emergent light; and a first lens for receiving the diffracted light of the first outgoing light and imaging the diffracted light of the first outgoing light toward the first photosensitive element.
4. The extended OCT imaging depth spectrometer of claim 3, further comprising a second grating and a second lens disposed on the second optical path, wherein: The second grating is used for receiving the second emergent light and diffracting the second emergent light to form diffracted light of the second emergent light; And a second lens for receiving the diffracted light of the second outgoing light and imaging the diffracted light of the second outgoing light toward the second photosensitive element.
5. The extended OCT imaging depth spectrometer of claim 4, wherein the first grating and the second grating are identical in structure.
6. The extended OCT imaging depth spectrometer of claim 4, wherein a first angle of incidence is formed between the first exit light and the first grating, and a second angle of incidence is formed between the second exit light and the second grating, the first angle of incidence being the same as the second angle of incidence.
7. The extended OCT imaging depth spectrometer of claim 1, wherein the first and second exit lights are parallel lights.
8. The extended OCT imaging depth spectrometer of claim 1, wherein there is a partial overlap between the first range of first exit light wavelengths and the second range of second exit light wavelengths.
9. The extended OCT imaging depth spectrometer of claim 1, wherein the first photosensitive element and the second photosensitive element have a partially overlapping region of reception wavelength ranges in the spectral direction.
10. The extended OCT imaging depth spectrometer of claim 8, wherein the first photosensitive element and the second photosensitive element form an optical conjugate: the image surfaces corresponding to the first photosensitive element and the second photosensitive element are positioned at equivalent imaging plane positions and have consistent imaging rules; The first photosensitive element and the second photosensitive element respectively receive spectral images in different wavelength ranges, wherein in the overlapped wave band covered by the two photosensitive elements, the imaging positions of the same wavelength components on the two image planes have a certain corresponding relation.
11. A fusion imaging method of a spectrometer for expanding OCT imaging depth, comprising the steps of: registering a first photosensitive element and a second photosensitive element in the extended OCT imaging depth spectrometer of any of claims 1-10; Acquiring corresponding wavelength information of each pixel of the first photosensitive element and the second photosensitive element after registration of the light source to be imaged; Respectively acquiring spectrum data of the first photosensitive element and the second photosensitive element in a wavelength overlapping region and a wavelength non-overlapping region, so as to obtain continuous spectrum data; Based on the continuous spectrum data, fusion imaging is completed.
12. The fusion imaging method of a spectrometer for enlarging an OCT imaging depth according to claim 11, wherein the acquiring of the spectral data of the first photosensitive element and the second photosensitive element in the wavelength overlapping region and the wavelength non-overlapping region, respectively, further comprises: in the wavelength overlapping interval, calculating the fusion data of the spectrum intensities acquired by the first photosensitive element and the second photosensitive element as the fusion spectrum data of the wavelength overlapping interval; in the non-overlapping wavelength interval, directly adopting spectrum data corresponding to the first photosensitive element and the second photosensitive element as independent spectrum data; And combining the fused spectrum data of the wavelength overlapping region and the independent spectrum data of the wavelength non-overlapping region to obtain continuous spectrum data.
13. The fusion imaging method of a spectrometer for extending OCT imaging depth of claim 12, wherein the fused spectral data for the overlapping wavelength intervals is calculated using weighted average fusion, signal-to-noise ratio based weight fusion, or optimized fusion based on minimum error criteria.
14. The fusion imaging method of a spectrometer for extending OCT imaging depth of claim 11, wherein the registration of the first photosensitive element and the second photosensitive element comprises: Acquiring an original spectrum and a shaped spectrum of a light source; Sequentially inputting the original spectrum and the shaped spectrum into a spectrometer for enlarging the OCT imaging depth to obtain the wavelength corresponding to each pixel; Constructing an evaluation coefficient based on the wavelength corresponding to each pixel; and adjusting the positions of the first photosensitive element and the second photosensitive element, and circularly calculating an evaluation coefficient until a set stop condition is reached, so as to realize the registration of the first photosensitive element and the second photosensitive element.
15. The fusion imaging method of a spectrometer for extending OCT imaging depth of claim 14, further comprising, after obtaining the corresponding wavelength information for each pixel on the first photosensitive element and the second photosensitive element after registration of the light source to be imaged: The spectrum data of the light source to be imaged, which are collected by the first photosensitive element and the second photosensitive element, are mapped to a unified wavelength coordinate system to form a wavelength-intensity data pair; and determining an overlapped band interval of the first photosensitive element and the second photosensitive element according to the receiving wavelength ranges of the first photosensitive element and the second photosensitive element, and dividing the wavelength overlapped interval and the wavelength non-overlapped interval.

Description

Spectrometer for enlarging OCT imaging depth and fusion imaging method Technical Field The invention belongs to the technical field of optical coherence tomography, and particularly relates to a spectrometer for enlarging OCT imaging depth and a fusion imaging method. Background In OCT detection, the imaging depth and the transmittance of the object to be measured are related to the detectable frequency of the spectrometer, and the detectable frequency of the spectrometer is affected by the spectral resolution of the detector, the greater the spectral resolution, the greater the detectable frequency of the spectrometer and the detectable depth of the OCT. The spectral resolution of the spectrometer is only related to the number of pixels of the camera when the spectral range is fixed, and if a camera with a high number of pixels is simply used, the high pixels will cause limited transmission speed and affect the scanning speed of the system. And the number of pixels of the camera in the prior art is fixed, and the spectral resolution of the spectrometer cannot be improved without a camera with a larger number of pixels. In the prior art, a technology for receiving spectrums by using a plurality of cameras exists, for example, a Chinese patent invention named as a high-resolution jump type multiband spectrometer and a working method, and although the image resolution and the imaging depth of OCT are improved, continuous spectrum acquisition cannot be realized by the technology, and the spectrum discontinuity causes processed OCT images to generate side lobe noise so as to influence the imaging effect. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides a spectrometer for enlarging the imaging depth of OCT and a fusion imaging method, which are characterized in that incident light is subjected to light splitting treatment through a dichroic mirror to obtain first emergent light and second emergent light, a first photosensitive element is arranged at a position imaged by the first emergent light with the wavelength in a first range, a second photosensitive element is arranged at a position imaged by the second emergent light with the wavelength in a second range, the first range of the first emergent light wavelength and the second range of the second emergent light wavelength are partially overlapped, the number of equivalent pixels finally obtained is larger than that of pixels of a single camera, so that OCT brings higher spectral resolution under the condition that the spectral range is unchanged, and larger imaging depth is realized. To achieve the above object, one or more embodiments of the present invention provide the following technical solutions: A first aspect of the invention provides a spectrometer that enlarges the imaging depth of OCT. A spectrometer for expanding OCT imaging depth comprising a dichroic mirror, a first photosensitive element, and a second photosensitive element: A dichroic mirror for receiving incident light entering the spectrometer and dividing the incident light into a first outgoing light and a second outgoing light; a first photosensitive element disposed at a position where the first outgoing light having a wavelength in the first range is imaged, for imaging the first outgoing light having a wavelength in the first range; and the second photosensitive element is arranged at a position imaged by the second emergent light with the wavelength in the second range and is used for imaging the second emergent light with the wavelength in the second range. Alternatively, the first outgoing light is imaged to the first photosensitive element along a first optical path, and the second outgoing light is imaged to the second photosensitive element along a second optical path. As an alternative technical solution, the optical system further comprises a first grating and a first lens, wherein the first grating and the first lens are arranged on the first optical path, and the first grating and the first lens are arranged on the first optical path: the first grating is used for receiving the first emergent light and diffracting the first emergent light to form diffracted light of the first emergent light; and a first lens for receiving the diffracted light of the first outgoing light and imaging the diffracted light of the first outgoing light toward the first photosensitive element. As an alternative technical solution, the optical system further comprises a second grating and a second lens arranged on the second optical path, wherein: The second grating is used for receiving the second emergent light and diffracting the second emergent light to form diffracted light of the second emergent light; And a second lens for receiving the diffracted light of the second outgoing light and imaging the diffracted light of the second outgoing light toward the second photosensitive element. Alternatively, the first grating and the second grating have