阅读说明：本技术 一种单光谱仪多光束光学相干层析成像仪 (Multi-beam optical coherence tomography instrument of single spectrometer ) 是由 刘海军 苗丛 于 2019-09-16 设计创作，主要内容包括：本发明公开了一种单光谱仪多光束光学相干层析成像仪,包括N个宽带光源、N个与宽带光源一一对应的三端口循环器、第一光纤阵列、干涉分光器、参考臂、样品臂、光谱仪、第二光纤阵列以及图像采集设备。本发明通过增加照射样品的光束数量N来实现扫描速度的提升。每个光束来自一个独立的光源,并且光源的光谱范围之间没有重合。本发明只需要一个光谱仪就能完成所有光束的信号收集,节约了成本。(The invention discloses a single spectrometer multi-beam optical coherence tomography instrument which comprises N broadband light sources, N three-port circulators in one-to-one correspondence with the broadband light sources, a first optical fiber array, an interference splitter, a reference arm, a sample arm, a spectrometer, a second optical fiber array and image acquisition equipment. The invention increases the scanning speed by increasing the number N of light beams irradiating the sample. Each light beam comes from a separate light source and there is no overlap between the spectral ranges of the light sources. The invention can complete the signal collection of all light beams by only one spectrometer, thereby saving the cost.)

1. The utility model provides a many beam optics of single spectrometer coherence tomography appearance which characterized in that, includes N broadband light source, N and broadband light source one-to-one three-port circulator, first fiber array, interference beam splitter, reference arm, sample arm, spectrum appearance, second fiber array and image acquisition equipment, N broadband light source, N and broadband light source one-to-one three-port circulator, first fiber array, interference beam splitter, reference arm, sample arm, spectrum appearance, second fiber array set up to:

n light beams emitted by the N broadband light sources respectively enter the three-port circulator corresponding to the N broadband light sources, the light beams output from the output port of the three-port circulator are output to the interference beam splitter through the first optical fiber array, are divided into sample light and reference light, respectively and correspondingly enter the sample arm and the reference arm, and the light reaching the sample arm is scattered by a sample and then returns to the interference beam splitter in an original path; similarly, light reaching the reference arm returns to the interference light splitter according to the original path after being reflected by the reference reflector, light signals returning from the sample arm and the reference arm enter the spectrometer through the first optical fiber array, the other output port of the three-port circulator and the second optical fiber array after being interfered by the interference light splitter, and the spectrometer converts the interference light signals into electric signals;

the image acquisition equipment is used for acquiring an electric signal in the spectrometer;

The spectral ranges of the light beams emitted by the N broadband light sources are continuous but not coincident, and N is a natural number greater than 1.

2. The single-spectrometer multi-beam optical coherence tomography instrument of claim 1, wherein the first and second fiber arrays each comprise not less than N parallel equally spaced fibers.

3. The single-spectrometer multi-beam optical coherence tomography instrument of claim 2, wherein the N fibers of the first array are aligned in a direction parallel or perpendicular to the fast axis of the beam scanning device.

4. The single spectrometer multi-beam optical coherence tomography instrument of claim 1, wherein the sample arm comprises a beam scanning device, a first objective lens placed behind the beam scanning device, the sample being placed at the focus of the first objective lens.

5. The single spectrometer multi-beam optical coherence tomography instrument of claim 1, wherein the reference arm comprises a second objective lens and a flat mirror disposed at a focal point of the second objective lens.

6. The single-spectrometer multi-beam optical coherence tomography instrument of claim 1, wherein the spectrometer comprises a collimating mirror disposed on the fourier surface of the second fiber array, a grating disposed such that collimated light rays emitted from the collimating mirror are incident along a nominal angle of incidence of the grating, a camera lens disposed opposite the grating, and a line camera disposed on the back focal plane of the camera lens.

Technical Field

The invention belongs to the optical imaging technology, and particularly relates to a multi-beam optical coherence tomography imaging instrument of a single spectrometer.

Background

Optical Coherence Tomography (OCT) is an emerging optical imaging technique. It forms a high resolution biological tissue profile in a non-invasive manner and at extremely high speed. Since 1991, the technology brings significant influence on clinical diagnosis and medical research. Over 2000 million patients have been beneficiaries of OCT imaging technology each year over the last 10 years. However, the existing OCT has two problems, firstly, due to the movement of the tissue to be measured in the living body, the OCT is required to scan a large tissue range in a very short time, and the scanning speed of the existing OCT equipment seriously hinders the popularization of the effective diagnosis technology; second, the axial resolution of existing OCT devices is limited (5-12 microns), resulting in the loss of cellular information on the order of 1 micron, which affects their wider application to some extent.

as shown in fig. 1, a typical SD-OCT apparatus includes: a broadband light source 110; a circulator 120; an interference beam splitter 130; a reference arm 140; a sample arm 150; a spectrometer 160; an image acquisition device 170. The output broadband light source is transmitted to the interference beam splitter through ports 1 and 2 of the circulator. The interference beam splitter is the core of the interferometer, and usually has 4 interfaces, which are respectively connected with a light source, a reference arm, a spectrometer and a sample arm. The output of the broadband light source is split by the interference beam splitter into two parts, one part to the sample arm and the other part to the reference arm. The light reaching the sample arm is scattered by the sample and returns to the interference beam splitter in the original path; similarly, light reaching the reference arm is reflected by the reference mirror and returned to the interference beam splitter in the original path. Two beams of light returning to the interference beam splitter interfere at the interference beam splitter, part of the interference light reaches the spectrometer through the 2 ports and the 3 ports of the circulator, and the spectrometer converts the interference light into an electric signal after receiving the interference light. The computer reads the output data of the spectrograph containing the spectrum interference signal from the spectrograph, and the cross-section image of the sample is obtained after the linear correction and the inverse Fourier change of the spectrum domain.

However, the image acquisition speed of typical SD-OCT is limited by the speed of the line detector in the spectrometer. The image acquisition speed of OCT is measured by the axial line scan speed (a-line rate). One line of the linear array detector corresponds to one axial line scanning, so the line frequency of the linear array detector is the image acquisition speed of the SD-OCT. The maximum line frequency of the existing linear array detector is 250K Hz, which is smaller than the actual requirement (1M Hz or higher).

Disclosure of Invention

the invention aims to provide a single spectrometer multi-beam optical coherence tomography instrument.

The technical solution for realizing the invention is as follows: a single spectrometer multi-beam optical coherence tomography instrument comprises N broadband light sources, N three-port circulators in one-to-one correspondence with the broadband light sources, a first optical fiber array, an interference splitter, a reference arm, a sample arm, a spectrometer, a second optical fiber array and image acquisition equipment, wherein the N broadband light sources, the N three-port circulators in one-to-one correspondence with the broadband light sources, the first optical fiber array, the interference splitter, the reference arm, the sample arm, the spectrometer and the second optical fiber array are arranged as follows:

N light beams emitted by the N broadband light sources respectively enter the three-port circulator corresponding to the N broadband light sources, the light beams output from the output port of the three-port circulator are output to the interference beam splitter through the first optical fiber array, are divided into sample light and reference light, respectively and correspondingly enter the sample arm and the reference arm, and the light reaching the sample arm is scattered by a sample and then returns to the interference beam splitter in an original path; similarly, light reaching the reference arm returns to the interference light splitter according to the original path after being reflected by the reference reflector, light signals returning from the sample arm and the reference arm enter the spectrometer through the first optical fiber array, the other output port of the three-port circulator and the second optical fiber array after being interfered by the interference light splitter, and the spectrometer converts the interference light signals into electric signals;

The image acquisition equipment is used for acquiring an electric signal in the spectrometer;

The spectral ranges of the light beams emitted by the N broadband light sources are continuous but not coincident, and N is a natural number greater than 1.

Preferably, the first optical fiber array and the second optical fiber array respectively comprise not less than N optical fibers which are arranged in parallel at equal intervals.

Preferably, the arrangement direction of the N optical fibers of the first optical fiber array is parallel or perpendicular to the fast axis direction of the optical beam scanning device.

Preferably, the sample arm comprises a beam scanning device, a first objective lens placed behind the beam scanning device, the sample being placed at the focus of the first objective lens.

Preferably, the reference arm comprises a second objective lens and a plane mirror arranged at a focal point of the second objective lens.

Preferably, the spectrometer comprises a collimating mirror, a grating, a camera lens and a line-scan camera, wherein the collimating mirror is arranged on a fourier plane surface of the second optical fiber array, the grating is arranged such that collimated light rays emitted by the collimating mirror are incident along a nominal incident angle of the grating, the camera lens is arranged opposite to the grating, and the line-scan camera is arranged on a back focal plane of the camera lens.

compared with the prior art, the invention has the following remarkable advantages: the invention adopts the multi-beam irradiation technology to improve the scanning speed and the axial resolution; the invention can complete the signal collection of all light beams by only one spectrometer, thereby saving the cost.

The present invention is described in further detail below with reference to the attached drawings.

Drawings

fig. 1 is a schematic structural view of a conventional SD-OCT apparatus.

Fig. 2 is a schematic structural diagram of the present invention.

Detailed Description

A single spectrometer multi-beam optical coherence tomography instrument comprises N broadband light sources, N three-port circulators in one-to-one correspondence with the broadband light sources, a first optical fiber array, an interference splitter, a reference arm, a sample arm, a spectrometer, a second optical fiber array and image acquisition equipment, wherein the N broadband light sources, the N three-port circulators in one-to-one correspondence with the broadband light sources, the first optical fiber array, the interference splitter, the reference arm, the sample arm, the spectrometer and the second optical fiber array are arranged as follows:

N light beams emitted by the N broadband light sources respectively enter the three-port circulator corresponding to the N broadband light sources, the light beams output from the output port of the three-port circulator are output to the interference beam splitter through the first optical fiber array, are divided into sample light and reference light, respectively and correspondingly enter the sample arm and the reference arm, and the light reaching the sample arm is scattered by a sample and then returns to the interference beam splitter in an original path; similarly, light reaching the reference arm returns to the interference light splitter according to the original path after being reflected by the reference reflector, light signals returning from the sample arm and the reference arm enter the spectrometer through the first optical fiber array, the other output port of the three-port circulator and the second optical fiber array after being interfered by the interference light splitter, and the spectrometer converts the interference light signals into electric signals;

The image acquisition equipment is used for acquiring an electric signal in the spectrometer;

The spectral ranges of the light beams emitted by the N broadband light sources are continuous but not coincident, and N is a natural number greater than 1.

In a further embodiment, the first optical fiber array and the second optical fiber array respectively comprise not less than N optical fibers which are arranged in parallel at equal intervals.

In a further embodiment, the arrangement direction of the N optical fibers of the first optical fiber array is parallel or perpendicular to the fast axis direction of the optical beam scanning device. The arrangement direction of the optical fibers is actually a distinction between a two-dimensional plane in which the optical fibers are arranged along the horizontal axis and in which the optical fibers are arranged along the vertical axis. When the optical fiber arrangement direction is parallel to the fast axis direction of the optical beam scanning device, the scanning paths of all the optical fibers are parallel and mostly overlapped, although different optical beams scan different sample points at the same time point, all the optical beams pass through all the sample points on the scanning paths, so that the optical beams with all the wavelengths have return optical signals for each sample point.

When the optical fibers are arranged in a direction perpendicular to the fast axis direction of the optical beam scanning apparatus, the scanning paths of all the optical fibers are parallel but do not coincide. The optical fiber does not move during the scanning process, and the optical beam scanning device scans all the optical beams.

in a further embodiment, the sample arm comprises a beam scanning device, a first objective lens placed behind the beam scanning device, the sample being placed at the focus of the first objective lens.

In a further embodiment, the reference arm comprises a second objective lens and a plane mirror arranged at a focal point of the second objective lens.

In a further embodiment, the spectrometer comprises a collimating mirror, a grating, a camera lens and a line camera, the collimating mirror is disposed on a fourier surface of the second optical fiber array, the grating is configured such that collimated light emitted by the collimating mirror enters along a nominal incident angle of the grating, the camera lens is disposed opposite to the grating, and the line camera is disposed on a back focal plane of the camera lens.

The invention increases the scanning speed by increasing the number N of light beams irradiating the sample. Each light beam comes from a separate light source and there is no overlap between the spectral ranges of the light sources. The invention can complete the signal collection of all light beams by only one spectrometer, thereby saving the system cost.

The arrangement direction of the optical fibers is perpendicular to the fast axis direction of the light beam scanning device, so that N tomographic images can be obtained in one B-mode scanning, the distance between two adjacent tomographic images is d/M, wherein d is the distance between two optical fiber pinholes, and M is the optical magnification of the sample arm from the object plane to the section of the optical fiber. Wherein, the B mode refers to a tomography mode, namely longitudinal section two-dimensional scanning. The invention can also realize the amplification of the spectral width by increasing the number N of the light beams irradiating the sample, thereby improving the axial resolution by times. Each light beam comes from a separate light source, and the spectral ranges of the light sources are continuous but not coincident, so that a wide spectral signal with the spectral width expanded by N times can be obtained by each exposure on the spectrometer.

Since OCT axial resolution is proportional to the spectral width, the axial resolution can be increased by a factor of N. In this case, the optical fibers are arranged in a direction parallel to the fast axis direction of the optical beam scanning device, and can be irradiated with all the optical beams (or spectra) at any point on the object plane.