阅读说明：本技术 一种光热光学相干层析成像方法及系统 (A kind of photo-thermal optical coherence chromatography imaging method and system ) 是由 魏波 唐志列 袁治灵 于 2019-07-29 设计创作，主要内容包括：本发明涉及一种光热光学相干层析成像方法及系统,通过在同一位置重复采集光谱信号,将经过傅里叶变换的光谱信号与参考调制信号进行互相关运算,通过用相同周期内的理想信号积分面积和所述光热信号采样面积求解平均幅值,将所述平均幅值乘上设定的光程差与平均幅值的比值,获得光程差；将获取的光程差进行归一化获得信号幅值比,根据信号幅值比进行光热成像,相对于现有技术,本发明可在特定深度范围内和复杂形貌条件实现清晰成像。(The present invention relates to a kind of photo-thermal optical coherence chromatography imaging method and systems, by in same position repeated acquisition spectral signal, computing cross-correlation is carried out by the spectral signal Jing Guo Fourier transformation and with reference to modulated signal, by in same period ideal signal integral area and the Photothermal Signals sampling area solve average amplitude, the average amplitude is multiplied by the optical path difference of setting and the ratio of average amplitude, obtains optical path difference；The optical path difference that will acquire, which is normalized, obtains signal amplitude ratio, and according to signal amplitude than carrying out photothermal imaging, compared with the existing technology, the present invention can be within the scope of certain depth and complex topography condition realizes blur-free imaging.)

1. a kind of photo-thermal optical coherence chromatography imaging method, it is characterised in that: the following steps are included:

In same position repeated acquisition spectral signal；

Fourier transformation processing is carried out to spectral signal, treated spectral signal and modulated signal f (t)=sin (2 π will be referred to f₀T) computing cross-correlation is carried out, Photothermal Signals are obtained；Wherein f₀To pump light modulation frequency, t is irradiation time；Utilize identical week Ideal signal integral area and the Photothermal Signals sampling area in phase solve average amplitude, and the average amplitude is multiplied by and is set The ratio of fixed optical path difference and average amplitude obtains optical path difference；

The optical path difference that will acquire, which is normalized, obtains signal amplitude ratio, according to signal amplitude than carrying out photothermal imaging.

2. photo-thermal optical coherence chromatography imaging method according to claim 1, it is characterised in that: carried out to spectral signal It is further comprising the steps of before Fourier transformation processing step: to be carried out after collected spectral signal is subtracted background light signal Interpolation arithmetic, wherein the background light signal is to block the collected spectral signal of sample arm.

3. photo-thermal optical coherence chromatography imaging method according to claim 1, it is characterised in that: described to utilize same period The step of interior ideal signal integral area and the Photothermal Signals sampling area solve average amplitude specifically includes: in the phase people having the same aspiration and interest In period processed, it would be desirable to analyze signal integration and obtain ideal signal area, by multiplying for the Photothermal Signals and sampling interval duration Product summation obtains actual samples area, it would be desirable to which signal area and actual samples area are considered as equal, solution average amplitude.

4. a kind of photo-thermal optical coherence tomography system, it is characterised in that: include:

Spectroscopic acquisition device, in same position repeated acquisition spectral signal；

Light signal processing device, the light signal processing device include:

Optical path difference obtains module, will treated spectral signal and reference for carrying out Fourier transformation processing to spectral signal Modulated signal f (t)=sin (2 π f₀T) computing cross-correlation is carried out, Photothermal Signals are obtained；Wherein f₀To pump light modulation frequency, t is Irradiation time；Using in same period ideal signal integral area and the Photothermal Signals sampling area solve average amplitude, The average amplitude is multiplied by the optical path difference of setting and the ratio of average amplitude, obtains optical path difference；

Photothermal imaging module, the optical path difference for will acquire be normalized obtain signal amplitude ratio, according to signal amplitude ratio into Row photothermal imaging.

5. photo-thermal optical coherence tomography system according to claim 4, it is characterised in that: the spectroscopic acquisition Device include laser, optical circulator, wide-band coupler, reference arm, sample arm, collimation lens, body phase hologram transmission grating, Condenser lens and linear array CCD camera, the laser are connect with wide-band coupler by optical circulator, and the wide-band coupler will The light beam that laser issues is exported respectively to reference arm and sample arm；It is returned from the light of reference arm return and from the light that sample arm returns It returns wide-band coupler and forms interference light, the interference light is from successively collimated lens, body phase hologram after wide-band coupler outgoing Transmission grating and condenser lens focus on linear array CCD camera the acquisition for carrying out spectral signal.

6. photo-thermal optical coherence tomography system according to claim 4, it is characterised in that: the reference arm includes position In optical fiber collimator, condenser lens and plane mirror in same optical path, the collimated light beam after optical fiber collimator collimates is defeated Out to condenser lens, light backtracking wide-band coupler after line focus lens focus to plane mirror；

The sample arm includes optical fiber collimator, pump laser and condenser lens, the directional light after optical fiber collimator collimates The modulated laser that beam and pump laser issue is focused on sample by condenser lens, the scattering light backtracking of sample To wide-band coupler.

7. photo-thermal optical coherence tomography system according to claim 4, it is characterised in that: the optical path difference obtains mould Block is within identical modulation period, it would be desirable to and it analyzes signal integration and obtains ideal signal area, it will be between the Photothermal Signals and sampling Actual samples area is obtained every the product summation of time, it would be desirable to which signal area and actual samples area are considered as equal, solve flat Equal amplitude.

8. photo-thermal optical coherence tomography system according to claim 4, it is characterised in that: the sample arm further includes Two-dimensional scanning mirrors device, the two-dimensional scanning mirrors device are arranged between optical fiber collimator and condenser lens, the two dimension Scanning galvanometer device includes the first galvanometer and the second galvanometer, and the two-dimensional scanning mirrors device is used to control the two-dimensional scanning of light beam Position reflexes to the collimated light beam that optical fiber collimator is emitted on condenser lens.

9. photo-thermal optical coherence tomography system according to claim 4, it is characterised in that: the optical path difference obtains mould Block is carrying out Fourier transformation processing step to spectral signal, collected spectral signal is subtracted carry out after background light signal it is slotting It is worth operation, wherein the background light signal is to block collected spectral signal after sample.

Technical field

The present invention relates to optical imaging fields, more particularly, to a kind of photo-thermal optical coherence chromatography imaging method and system.

Background technique

Optical coherence tomography scanning (OCT) is a kind of contactless high-resolution, the imaging technique that can carry out three-dimensional imaging. Since it has the advantages such as non-invasive, tomography, high-resolution, more and more extensive research is received, in recent years, in eye Section, biological tissue's detection etc. play an important role.Photo-thermal effect refers to endogenous or exogenous suction in sample Luminous energy is converted to thermal energy by receipts agent leads to the variations in refractive index and elastic expansion of sample interior, finally causes the variation of optical path difference. Photothermal imaging can combine both, and directly carry out endogenous to organization internal photo-thermal effect using OCT system and visit in situ It surveys.In general, in OCT system-based, the pump light of modulation is Chong Die with the focal position of sample arm, available photo-thermal OCT (PT-OCT) system.The available sample absorption coefficient of PT-OCT is distributed and has longitudinal resolution identical with OCT and chromatography Ability；It only needs the detection light beam progress to pump light and OCT coaxial, other cores is had no need to change when replacing different light sources Point, it is convenient and efficient.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings of the existing technology and deficiency, provides a kind of photo-thermal optics phase of blur-free imaging Dried layer analyses imaging method and system.

A kind of photo-thermal optical coherence chromatography imaging method, it is characterised in that:

In same position repeated acquisition spectral signal；

Fourier transformation processing is carried out to spectral signal, will treated spectral signal and with reference to modulated signal f (t)= sin(2πf₀T) computing cross-correlation is carried out, Photothermal Signals are obtained；Wherein f₀To pump light modulation frequency, t is irradiation time；It utilizes Ideal signal integral area and the Photothermal Signals sampling area in same period solve average amplitude, by the average amplitude It is multiplied by the optical path difference of setting and the ratio of average amplitude, obtains optical path difference；

The optical path difference that will acquire, which is normalized, obtains signal amplitude ratio, according to signal amplitude than carrying out photothermal imaging.

Referring now to the prior art, the present invention treated by will carry out Fourier transformation spectral signal and believe with reference to modulation Number carry out computing cross-correlation, extract effective Photothermal Signals and inhibit noise, by in same period ideal signal integrate face The long-pending and Photothermal Signals sampling area solves average amplitude, obtains light path according to the scale parameter of optical path difference and average amplitude Difference；The optical path difference that will acquire, which is normalized, obtains signal amplitude ratio, is mentioned according to signal amplitude than carrying out photothermal imaging, the present invention High low signal areas image contrast, can realize blur-free imaging within the scope of certain depth and under the conditions of complex topography.

In an embodiment of the invention, to spectral signal carry out Fourier transformation processing step before, further include with Lower step: collected spectral signal is subtracted into the laggard row interpolation operation of background light signal, wherein the background light signal is to hide Collected spectral signal after gear sample.By the way that collected spectral signal is subtracted the laggard row interpolation operation of background light signal, Interference of the environment to sample optical signal is reduced, photothermal imaging effect is improved.

In an embodiment of the invention, the ideal signal integral area using in same period and photo-thermal letter Number sampling area solves the step of average amplitude and specifically includes: within identical modulation period, it would be desirable to analyze signal integration acquisition The product of the Photothermal Signals and sampling interval duration is summed and obtains actual samples area, it would be desirable to believed by ideal signal area Number area and actual samples area are considered as equal, solve average amplitude.By combining to ideal signal area actual samples area Average amplitude is solved, influence of the noise to solving result is reduced, improves accuracy.

The present invention also provides a kind of photo-thermal optical coherence tomography systems, comprising:

Spectroscopic acquisition device, in same position repeated acquisition spectral signal

Optical path difference obtains module, for carrying out Fourier transformation processing to spectral signal, will treated spectral signal with With reference to modulated signal f (t)=sin (2 π f₀T) computing cross-correlation is carried out, Photothermal Signals are obtained；Wherein f₀For pumping light modulation frequency Rate, t are irradiation time；Using in same period ideal signal integral area and the Photothermal Signals sampling area solve it is average The average amplitude is multiplied by the optical path difference of setting and the ratio of average amplitude by amplitude, obtains optical path difference；

Photothermal imaging module, the optical path difference for will acquire, which is normalized, obtains signal amplitude ratio, according to signal amplitude Than carrying out photothermal imaging.

In an embodiment of the invention, the spectroscopic acquisition device includes laser, optical circulator, broadband couple device Device, reference arm, sample arm, collimation lens, body phase hologram transmission grating, condenser lens and linear array CCD camera, the laser It is connect with wide-band coupler by optical circulator, the wide-band coupler exports the light beam that laser issues respectively to reference arm And sample arm；The light returned from reference arm and the light returned from sample arm return to wide-band coupler and form interference light, the interference Successively collimated lens, body phase hologram transmission grating and condenser lens focus on line array CCD to light after wide-band coupler outgoing The acquisition of spectral signal is carried out on camera.

In an embodiment of the invention, the reference arm includes the optical fiber collimator being located in same optical path, focuses thoroughly Mirror and plane mirror, the collimated light beam after optical fiber collimator collimates are exported to condenser lens, and line focus lens focus is to flat Light backtracking wide-band coupler after the reflecting mirror of face；

The sample arm includes optical fiber collimator, pump laser and condenser lens, putting down after optical fiber collimator collimates The modulated laser that row light beam and pump laser issue is focused on sample by condenser lens, the road scattering Guang Yuan of sample It is back to wide-band coupler.

In an embodiment of the invention, the optical path difference obtains module within identical modulation period, it would be desirable to analysis letter Number integral obtain ideal signal area, by the product of the Photothermal Signals and sampling interval duration sum obtain actual samples face Product, it would be desirable to which signal area and actual samples area are considered as equal, solution average amplitude.

In an embodiment of the invention, the sample arm further includes two-dimensional scanning mirrors device, the two-dimensional scanning vibration Lens device is arranged between optical fiber collimator and condenser lens, and the collimated light beam that optical fiber collimator is emitted is reflexed to condenser lens On, the two-dimensional scanning mirrors device includes the first galvanometer and the second galvanometer, and first galvanometer and the second galvanometer are arranged in parallel, Second galvanometer can be moved along the direction with parallel light path.

In an embodiment of the invention, the optical path difference obtains module and is carrying out Fourier transformation processing to spectral signal Collected spectral signal is subtracted the laggard row interpolation operation of background light signal by step, wherein the background light signal is to block Collected spectral signal after sample.

Referring now to the prior art, the present invention treated by will carry out Fourier transformation spectral signal and believe with reference to modulation Number carry out computing cross-correlation, extract effective Photothermal Signals and inhibit noise, by in same period ideal signal integrate face The long-pending and Photothermal Signals sampling area solves average amplitude, obtains light path according to the scale parameter of optical path difference and average amplitude Difference；The optical path difference that will acquire, which is normalized, obtains signal amplitude ratio, and according to signal amplitude than carrying out photothermal imaging, the present invention can Blur-free imaging is realized within the scope of certain depth and under the conditions of complex topography.

In order to better understand and implement, the invention will now be described in detail with reference to the accompanying drawings.

Detailed description of the invention

Fig. 1 is a kind of flow chart of photo-thermal optical coherence chromatography imaging method in the embodiment of the present invention 1；

Fig. 2 is a kind of structure chart of photo-thermal optical coherence tomography system in the embodiment of the present invention 2；

Fig. 3 is the structural schematic diagram of spectroscopic acquisition device 1 in the embodiment of the present invention 2；

Fig. 4 is existing photo-thermal optical coherence tomography system and photo-thermal optical coherent chromatographic imaging of the present invention system System carries out the tomographic map comparison of simulated experiment；

Fig. 5 is existing photo-thermal optical coherence tomography system and photo-thermal optical coherent chromatographic imaging of the present invention system System carries out the three-dimensional structure comparison diagram of mouse ear blood vessel imaging；

Fig. 6 is the gray value analysis chart of the same position in corresponding diagram 5；

Fig. 7 is to utilize the mouse tumor position after photo-thermal optical coherence tomography system of the present invention scanning inoculation breast cancer The three-dimensional imaging figure of epidermis.

Specific embodiment