CN112945130A - Ultrafast microscopic imaging system for simultaneously obtaining depth and surface information - Google Patents

Ultrafast microscopic imaging system for simultaneously obtaining depth and surface information Download PDF

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CN112945130A
CN112945130A CN202110152804.3A CN202110152804A CN112945130A CN 112945130 A CN112945130 A CN 112945130A CN 202110152804 A CN202110152804 A CN 202110152804A CN 112945130 A CN112945130 A CN 112945130A
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coupler
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ultrafast
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CN112945130B (en
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高磊
黄景晟
曹玉龙
朱涛
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Chongqing University
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00Measuring arrangements characterised by the use of optical techniques
    • G01B11/22Measuring arrangements characterised by the use of optical techniques for measuring depth
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00Measuring instruments characterised by the use of optical techniques
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    • G01B9/02041Interferometers characterised by particular imaging or detection techniques

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Abstract

本发明提供一种同时获得深度和表面信息的超快显微成像系统,包括激光发生器,激光发生器的输出端通过色散介质连接第一耦合器的输入端,第一耦合器的第一输出端连接环形器的第一端,环形器的第二端连接准直器的第一端,准直器的第二端与衍射器件的第一输入/输出端对准,衍射器件的第二输入/输出端与平凸透镜的平面对准,平凸透镜的凸面与待测样品对准,环形器的第三端与第二耦合器的第一输入端连接,第一耦合器的第二输出端通过可调延迟介质与第二耦合器的第二输入端连接,第二耦合器的输出端连接探测器的输入端,探测器的输出端连接高速示波器的输入端,高速示波器的输出端连接信号处理模块。

Figure 202110152804

The invention provides an ultrafast microscopic imaging system that simultaneously obtains depth and surface information, comprising a laser generator, an output end of the laser generator is connected to an input end of a first coupler through a dispersive medium, and a first output of the first coupler The end is connected to the first end of the circulator, the second end of the circulator is connected to the first end of the collimator, the second end of the collimator is aligned with the first input/output end of the diffractive device, and the second input of the diffractive device is / The output end is aligned with the plane of the plano-convex lens, the convex surface of the plano-convex lens is aligned with the sample to be tested, the third end of the circulator is connected to the first input end of the second coupler, and the second output end of the first coupler passes through The adjustable delay medium is connected to the second input end of the second coupler, the output end of the second coupler is connected to the input end of the detector, the output end of the detector is connected to the input end of the high-speed oscilloscope, and the output end of the high-speed oscilloscope is connected to the signal processing module.

Figure 202110152804

Description

Ultrafast microscopic imaging system for simultaneously obtaining depth and surface information
Technical Field
The invention belongs to the field of ultrafast microscopic imaging, and particularly relates to an ultrafast microscopic imaging system for simultaneously obtaining depth and surface information.
Background
The ultrafast imaging is mainly of two types, one is to perform one-dimensional diffraction on ultrafast laser by using one-dimensional diffraction devices such as prisms and gratings so as to perform line scanning on a sample to be detected, and the other is to perform two-dimensional diffraction on the ultrafast laser by adopting a mode of combining the gratings and a virtual phase array so as to perform surface scanning on the sample to be detected. Although the method has a good application prospect in the field of microscopic imaging, the depth information of the sample to be detected cannot be obtained. However, in the current technology for measuring the depth information of a sample to be measured, an Optical Coherence Tomography (OCT) technology is usually adopted, which is to intensively irradiate an optical pulse to one point of the sample to be measured, the point on the sample to be measured returns reflected light after receiving the optical pulse, and the depth information of the sample is reflected according to the change of a Free Spectral Range (FSR) of an interference spectrum in the reflected light.
Disclosure of Invention
The invention provides an ultrafast microscopic imaging system for simultaneously obtaining depth and surface information, which aims to solve the problem that the depth and surface information of a sample to be detected cannot be simultaneously obtained by using the same laser signal at present.
According to a first aspect of the embodiments of the present invention, there is provided an ultrafast microscopic imaging system for simultaneously obtaining depth and surface information, comprising a laser generator, an output terminal of the laser generator connected to an input terminal of a first coupler through a dispersive medium, a first output terminal of the first coupler connected to a first terminal of a circulator, a second terminal of the circulator connected to a first terminal of a collimator, a second terminal of the collimator aligned with a first input/output terminal of a diffraction device, a second input/output terminal of the diffraction device aligned with a plane of a plano-convex lens, a convex surface of the plano-convex lens aligned with a sample to be measured, a third terminal of the circulator connected to a first input terminal of a second coupler, a second output terminal of the first coupler connected to a second input terminal of the second coupler through an adjustable delay medium, an output terminal of the second coupler connected to an input terminal of a detector, the output end of the detector is connected with the input end of the high-speed oscilloscope, and the output end of the high-speed oscilloscope is connected with the signal processing module;
the dispersion medium stretches the laser signal generated by the laser generator in the time domain, the first coupler divides the stretched laser signal into two paths, wherein one path of laser signal is transmitted to the diffraction device through the circulator and the collimator in turn, the laser signal generates diffracted lights with different diffraction paths through the diffraction device, the diffracted lights with different diffraction paths are converted into a plurality of parallel lights through the plano-convex lens, the plurality of parallel lights irradiate different positions of the sample to be detected, the corresponding positions of the sample to be detected generate reflected lights after receiving the parallel lights, the reflectivity at the corresponding position is coded into the spectrum of the reflected light, and the reflected light is transmitted to the circulator through the plano-convex lens, the diffraction device and the collimator in sequence along the original transmission path; the circulator transmits the reflected light to the second coupler;
the adjustable delay medium delays another laser signal divided by the first coupler to perform optical path matching with the returned reflected light, and the delayed another laser signal is used as reference light to be transmitted to the second coupler; the reflected light and the reference light interfere at the second coupler to generate a reflected light interference signal, and the detector detects the reflected light interference signal to generate an electric signal; the high-speed oscilloscope performs analog-to-digital conversion on the electric signal to generate a digital signal;
the signal processing module determines the reflectivity of the sample to be detected at the corresponding position according to the spectral intensity of the digital signal, so as to determine the surface information of the corresponding position, performs Fourier transformation on the digital signal, and determines the depth information of the sample to be detected at the corresponding position according to the free spectral range of the digital signal after the Fourier transformation.
In an optional implementation manner, the device further includes a stepper motor, the same plane where each parallel light is located is a first plane, an X axis is located on the first plane and perpendicular to each parallel light, a Z axis is parallel to each parallel light, a Y axis is perpendicular to the X axis and the Z axis, the sample to be measured is located under at least part of the parallel light in each parallel light, so that the corresponding parallel light performs line scanning on the sample to be measured in the X axis direction, and the stepper motor drives the sample to be measured to move along the Y axis direction, so that the sample to be measured performs plane scanning of two dimensions of X-Y.
In another optional implementation, the optical fiber further comprises an optical amplifier, and the dispersive medium is connected with the input end of the first coupler through the optical amplifier.
In another optional implementation manner, the polarization controller is further included, and the third end of the circulator is connected to the second input end of the second coupler through the polarization controller.
In another alternative implementation, the laser signal includes a plurality of spectral costs having different wavelengths within a period.
In another alternative implementation, the laser generator is an ultrafast laser, the spectral range of the laser signal is on the order of tens of nanometers, and the pulse repetition rate is greater than megahertz.
In another optional implementation manner, the tunable delay medium performs delay processing on spectral components with different wavelengths in the laser signal according to the size of the wavelength, so as to implement optical path matching between the delayed spectral components and the returned reflected light.
In another alternative implementation, the size of the field of view of the system is determined by the dispersive power of the diffraction device, the focal length of the microscope objective, and the spectral bandwidth of the laser signal.
In another alternative implementation, the wavelength resolving power of the system is determined by several factors: the dispersion capacity of a dispersion medium, the spectral resolution capacity of Dispersion Fourier Transform (DFT) and the spectral resolution capacity determined by the bandwidths of a detector and a high-speed oscilloscope are the first, and the final spectral resolution capacity of the system is determined by the maximum of the three parameters.
In another alternative implementation, the imaging frame rate of the system is determined by the pulse frequency of the light source, typically the pulse frequency of the ultrafast laser is greater than megahertz; the effective frame rate of imaging also depends on the moving speed of the sample to be measured on the Y axis; the pixel point of the image is determined by the spectral width of the laser signal, the dispersion coefficient of the dispersion medium and the sampling rate of the high-speed oscilloscope.
The invention has the beneficial effects that:
1. the invention can simultaneously measure the depth and surface information of a sample to be measured by using the same laser signal, records the spectrum by using a Dispersion Fourier Transform (DFT) technology, and can directly collect the spectrum information by using a detector while ensuring the spectral resolution compared with the traditional spectrometer, thereby increasing the sampling rate to megahertz; the ultrafast laser can ensure that one pulse not only can contain spectral information up to dozens of nanometers, but also has a wider scanning range compared with the traditional Optical Coherence Tomography (OCT), and in addition, the ultrafast laser has the repetition frequency of megahertz, so that an imaging system can be ensured to have a higher imaging frame rate; the spatial position and the spectrum can be made to correspond by adopting a diffraction grating for dispersion, so that the information of different spatial positions of the sample can be reflected by the spectral intensity of the reflected light;
2. in addition, because the diffraction angles of the light with different wavelengths are fixed after the light with different wavelengths enters the diffraction device, when the position relationship between the diffraction device and the plano-convex lens is determined, the relationship between each parallel light and the X-axis coordinate is also fixed, and the reflected light can be identified from which X-coordinate position on the sample to be detected returns according to the wavelength of the returned reflected light; when the depth information is measured, the beam splitting light is not set for each parallel light, but the adjustable delay medium is set, so that the adjustable delay medium respectively delays the spectral components with different wavelengths in the laser signal according to the wavelength, and the optical path matching between the delayed spectral components and the returned reflected light is realized, therefore, the construction cost of multipoint depth measurement can be reduced, and the position of the conventionally arranged beam splitter is not required to be respectively adjusted even if the wavelength of the spectral components in the laser signal is changed, so that the adaptability is strong; before the laser signal is transmitted to the first coupler, the laser signal is stretched in the time domain through the dispersion medium (the spectrum and the light pulse are corresponding in the process), and compared with the traditional spectrometer, the spectrum signal can be directly collected by a detector while the spectrum resolution is ensured, so that the sampling rate is increased to megahertz;
3. the invention is also provided with a stepping motor, the sample to be detected is positioned under at least part of parallel light in each parallel light so as to enable the corresponding parallel light to carry out line scanning on the sample to be detected in the X-axis direction, and the stepping motor drives the sample to be detected to move along the Y-axis direction, so that the sample to be detected is subjected to surface scanning in two dimensions of X-Y.
Drawings
FIG. 1 is a schematic structural diagram of an embodiment of an ultrafast microscopic imaging system for simultaneously acquiring depth and surface information according to the present invention;
FIG. 2 is a schematic diagram of diffraction light output by a diffraction device being incident on a sample to be measured;
FIG. 3 is a schematic structural diagram of an ultrafast microscopic imaging system for acquiring depth and surface information simultaneously according to another embodiment of the present invention.
Detailed Description
In order to make the technical solutions in the embodiments of the present invention better understood and make the above objects, features and advantages of the embodiments of the present invention more comprehensible, the technical solutions in the embodiments of the present invention are described in further detail below with reference to the accompanying drawings.
In the description of the present invention, unless otherwise specified and limited, it is to be noted that the term "connected" is to be interpreted broadly, and may be, for example, a mechanical connection or an electrical connection, or a communication between two elements, or may be a direct connection or an indirect connection through an intermediate medium, and a specific meaning of the term may be understood by those skilled in the art according to specific situations.
Referring to fig. 1, a schematic structural diagram of an embodiment of an ultrafast microscopic imaging system for simultaneously acquiring depth and surface information according to the present invention is shown. The system can comprise a laser generator, wherein the output end of the laser generator is connected with the input end of a first coupler through a dispersion medium, the first output end of the first coupler is connected with the first end of a circulator, the second end of the circulator is connected with the first end of a collimator, the second end of the collimator is aligned with the first input/output end of a diffraction device, the second input/output end of the diffraction device is aligned with the plane of a plano-convex lens, the convex surface of the plano-convex lens is aligned with a sample to be measured, the third end of the circulator is connected with the first input end of a second coupler, the second output end of the first coupler is connected with the second input end of the second coupler through an adjustable delay medium, the output end of the second coupler is connected with the input end of a detector, and the output end of the detector is connected with the input end of a high-speed oscilloscope, and the output end of the high-speed oscilloscope is connected with the signal processing module.
The dispersion medium stretches the laser signal generated by the laser generator in the time domain, the first coupler divides the stretched laser signal into two paths, wherein one path of laser signal is transmitted to the diffraction device through the circulator and the collimator in turn, the laser signal generates diffracted lights with different diffraction paths through the diffraction device, the diffracted lights with different diffraction paths are converted into a plurality of parallel lights through the plano-convex lens, the plurality of parallel lights irradiate different positions of the sample to be detected, the corresponding positions of the sample to be detected generate reflected lights after receiving the parallel lights, the reflectivity at the corresponding position is coded into the spectrum of the reflected light, and the reflected light is transmitted to the circulator through the plano-convex lens, the diffraction device and the collimator in sequence along the original transmission path; the circulator transmits the reflected light to the second coupler.
The adjustable delay medium delays another laser signal divided by the first coupler to perform optical path matching with the returned reflected light, and the delayed another laser signal is used as reference light to be transmitted to the second coupler; the reflected light and the reference light interfere at the second coupler to generate a reflected light interference signal, and the detector detects the reflected light interference signal to generate an electric signal; the high-speed oscilloscope performs analog-to-digital conversion on the electric signal to generate a digital signal; the signal processing module determines the reflectivity of the sample to be detected at the corresponding position according to the spectral intensity of the digital signal, so as to determine the surface information of the corresponding position, performs Fourier transformation on the digital signal, and determines the depth information of the sample to be detected at the corresponding position according to the free spectral range corresponding to the digital signal after the Fourier transformation.
In this embodiment, after the incident light enters the diffraction device, the diffraction angle of the diffracted light output from the diffraction device is related to the wavelength of the incident light, that is, the diffraction paths of the incident light with different wavelengths corresponding to the diffracted light emitted from the diffraction device are different, so that in the ultra-fast imaging of the prior art or in the present invention, a laser signal generated by a laser generator includes a plurality of spectral components with different wavelengths within one period, so as to perform line scanning on a sample to be measured, wherein the same plane where each parallel light is located is set as a first plane, an X axis is located on the first plane and perpendicular to each parallel light, a Z axis is parallel to each parallel light, and a Y axis is perpendicular to both the X axis and the Z axis. In addition, in the conventional Optical Coherence Tomography (OCT) technique, a light pulse is intensively irradiated to a point of a sample to be measured, the point on the sample to be measured receives the light pulse and returns reflected light, and depth information of the sample is reflected according to a change in a Free Spectral Range (FSR) of an interference spectrum in the reflected light. Because the existing ultrafast imaging technology can already scan the line of the sample to be detected, and a plurality of points act on the sample to be detected in the process, when the existing ultrafast imaging technology is combined with an Optical Coherence Tomography (OCT) technology, a person skilled in the art usually thinks that the reflected light returned by the plurality of points on the sample to be detected in the existing ultrafast imaging technology is directly used for detecting the depth of each point, so that the number of points of the sample to be detected with depth information at a time is increased. However, as shown in fig. 2, when the second step from left to right in the sample to be measured is shown as a solid line, the diffracted light intersects with the point a in the sample to be measured, and when the second step in the sample to be measured is shown as a dotted line, the diffracted light intersects with the point B in the sample to be measured, and the positions of the point a and the point B on the sample to be measured are different, it can be seen that if the depth is directly detected by using the reflected light returned from the sample to be measured in the conventional ultrafast imaging technology, the same diffracted light cannot measure the depth of different samples to be measured at the same X-axis coordinate. Therefore, the plano-convex lens is added between the diffraction device and the sample to be measured, so that diffracted lights with different diffraction angles are vertically incident on the sample to be measured, each parallel light vertically incident on the sample to be measured corresponds to a unique X-axis coordinate, in addition, after the lights with different wavelengths are incident on the diffraction device, the diffraction angles are fixed, when the position relationship between the diffraction device and the plano-convex lens is determined, the relationship between each parallel light and the X-axis coordinate is also fixed, and according to the wavelength of the returned reflected light, the position of which X-axis coordinate the reflected light returns from on the sample to be measured can be identified.
In addition, the existing Optical Coherence Tomography (OCT) technology splits an optical signal incident on a sample to be measured, transmits a part of the optical signal to the sample to be measured, and transmits a part of the optical signal to a reference mirror. When a sample to be detected is not placed on the horizontal table surface below the plano-convex lens, and each horizontal light directly enters the horizontal table surface, on the premise that the positions of the diffraction device, the plano-convex lens and the horizontal table surface are fixed, aiming at each spectral component in the laser signal, after the diffraction device receives the spectral component with the corresponding wavelength, the optical path of the output diffracted light, the parallel light and the returned reflected light is fixed, so that the adjustable delay medium respectively performs delay processing on the spectral components with different wavelengths in the laser signal according to the wavelength, and the optical path matching between the delayed spectral components and the returned reflected light can be realized. When the depth information is measured, the adjustable delay medium is arranged instead of beam splitting light aiming at each parallel light, so that the adjustable delay medium respectively delays the spectral components with different wavelengths in the laser signal according to the wavelength, and the optical path matching between the delayed spectral components and the returned reflected light is realized, thereby not only reducing the construction cost of multipoint depth measurement, but also not needing to respectively adjust the position of the conventionally arranged beam splitter even if the wavelength of the spectral components in the laser signal changes, and having strong adaptability.
For the sample to be detected, when the sample to be detected is an ideal reflector, the intensity of the returned reflected light is the same as the intensity of the corresponding spectral component in the original laser signal, and when the surface of the sample to be detected is uneven, the reflectivity of the surface of the sample to be detected changes, and the intensity of the returned reflected light also changes, so that the signal processing module can determine the reflectivity of the sample to be detected at the corresponding position according to the spectral intensity corresponding to the digital signal, and further determine the surface information of the corresponding position. For a sample to be detected with a layered structure, the free spectral ranges FSR of interference spectra of reflected light at different depth positions are different correspondingly due to different optical path differences, so that Fourier change is performed on digital signals corresponding to the reflected light interference signals output by the second coupler, and depth information of the sample to be detected at the corresponding position can be determined according to the free spectral range of the digital signals after Fourier change. In addition, the laser generator can be an ultrafast laser, the spectral range of the laser signal can be tens of nanometers, the pulse repetition frequency is greater than megahertz, the spectral range of the laser signal can be tens of nanometers, compared with the traditional Optical Coherence Tomography (OCT) technology, the laser generator has a wider scanning range, the laser signal has the repetition frequency of megahertz, and the imaging system can be ensured to have a higher imaging frame rate. Before the laser signal is transmitted to the first coupler, the laser signal is stretched in the time domain through the dispersion medium (the spectrum and the optical pulse are corresponding in the process), and compared with a traditional spectrometer, the spectrum signal can be directly collected by a detector while the spectrum resolution is guaranteed, so that the sampling rate is increased to megahertz.
The structure can only realize the line scanning of the sample to be measured, and the synchronous measurement of the depth and the surface information on the corresponding position on the sample to be measured is realized in the line scanning process. In order to realize the surface scanning of the sample to be detected, the invention is also provided with a stepping motor, the sample to be detected is positioned under at least part of parallel light in each parallel light so as to enable the corresponding parallel light to carry out the line scanning on the sample to be detected in the X-axis direction, and the stepping motor drives the sample to be detected to move along the Y-axis direction, so that the surface scanning of the sample to be detected in two dimensions of X-Y is carried out. In one example, the laser generator may be: an ultrafast pulse laser with center wavelength of 1565nm, spectral bandwidth of 15nm and repetition frequency of MHz; the dispersion medium can be a dispersion compensation fiber with the dispersion coefficient of 1.2 ns/nm; the first coupler can be an 80:20 coupler, the low-power laser signal divided by the first coupler is transmitted to the adjustable delay medium, and the high-power laser signal is transmitted to the circulator; the diffraction device is a 1200-line diffraction grating; the power coupling ratio of the second coupler is 1: 1; the sampling rate of the detector is 50Gsa/s, the sampling time is longer than the pulse time after the dispersion medium is stretched, and the number of collected pulses depends on the size of a sample to be scanned and is limited by the storage capacity of the high-number oscillograph.
The field size of the microscopic imaging system is mainly determined by the dispersion capacity of the diffraction device, the focal length of the microobjective and the spectral bandwidth of the laser signal; the wavelength resolving power is mainly determined by several factors: the dispersion capacity of a dispersion medium, the spectral resolution capacity of Dispersion Fourier Transform (DFT) and the spectral resolution capacity determined by the bandwidth of digital devices such as a detector, a high-speed oscilloscope and the like are adopted, and the maximum spectral resolution capacity of the system is determined by the maximum of the three parameters; the imaging frame rate is mainly determined by the pulse frequency of the light source, and the pulse frequency of the ultrafast laser is usually greater than megahertz; the effective frame rate of imaging also depends on the moving speed of the sample to be measured on the Y axis; the pixel point of the image is mainly determined by the spectral width of the laser signal, the dispersion coefficient of the dispersion medium and the sampling rate of the high-speed oscilloscope.
The embodiment shows that the depth and surface information of a sample to be measured can be measured simultaneously by using the same laser signal, the spectrum is recorded by using a Dispersion Fourier Transform (DFT) technology, and compared with the traditional spectrometer, the spectrum analyzer can ensure the spectral resolution and directly collect the spectral information by using a detector, so that the sampling rate is increased to megahertz; the ultrafast laser can ensure that one pulse not only can contain spectral information up to dozens of nanometers, but also has a wider scanning range compared with the traditional Optical Coherence Tomography (OCT), and in addition, the ultrafast laser has the repetition frequency of megahertz, so that an imaging system can be ensured to have a higher imaging frame rate; the spatial position and the spectrum can be made to correspond by using the diffraction grating for dispersion, so that the spectral intensity of the reflected light can be used for reflecting the information of different spatial positions of the sample.
Referring to fig. 3, it is a schematic structural diagram of another embodiment of the ultrafast microscopic imaging system for simultaneously acquiring depth and surface information according to the present invention. Fig. 3 is different from the system shown in fig. 1 in that it further includes an optical amplifier and a polarization controller, the dispersive medium is connected to the input end of the first coupler through the optical amplifier, and the optical amplifier is used for amplifying the stretched laser signal; and the third end of the circulator is connected with the second input end of the second coupler through the polarization controller, and the polarization controller is used for adjusting the polarization state of the reflected light.
The embodiment shows that the depth and surface information of a sample to be measured can be measured simultaneously by using the same laser signal, the spectrum is recorded by using a Dispersion Fourier Transform (DFT) technology, and compared with the traditional spectrometer, the spectrum analyzer can ensure the spectral resolution and directly collect the spectral information by using a detector, so that the sampling rate is increased to megahertz; the ultrafast laser can ensure that one pulse not only can contain spectral information up to dozens of nanometers, but also has a wider scanning range compared with the traditional Optical Coherence Tomography (OCT), and in addition, the ultrafast laser has the repetition frequency of megahertz, so that an imaging system can be ensured to have a higher imaging frame rate; the spatial position and the spectrum can be made to correspond by using the diffraction grating for dispersion, so that the spectral intensity of the reflected light can be used for reflecting the information of different spatial positions of the sample.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is to be controlled solely by the appended claims.

Claims (10)

1.一种同时获得深度和表面信息的超快显微成像系统,其特征在于,包括激光发生器,所述激光发生器的输出端通过色散介质连接第一耦合器的输入端,所述第一耦合器的第一输出端连接环形器的第一端,所述环形器的第二端连接准直器的第一端,所述准直器的第二端与衍射器件的第一输入/输出端对准,所述衍射器件的第二输入/输出端与平凸透镜的平面对准,所述平凸透镜的凸面与待测样品对准,所述环形器的第三端与第二耦合器的第一输入端连接,所述第一耦合器的第二输出端通过可调延迟介质与所述第二耦合器的第二输入端连接,所述第二耦合器的输出端连接探测器的输入端,所述探测器的输出端连接高速示波器的输入端,所述高速示波器的输出端连接信号处理模块;1. an ultrafast microscopic imaging system that simultaneously obtains depth and surface information, is characterized in that, comprises a laser generator, and the output end of the laser generator is connected to the input end of the first coupler through a dispersive medium, and the The first output end of a coupler is connected to the first end of the circulator, the second end of the circulator is connected to the first end of the collimator, and the second end of the collimator is connected to the first input// The output end is aligned, the second input/output end of the diffractive device is aligned with the plane of the plano-convex lens, the convex surface of the plano-convex lens is aligned with the sample to be tested, the third end of the circulator is aligned with the second coupler The first input end of the first coupler is connected to the first input end of the first coupler, the second output end of the first coupler is connected to the second input end of the second coupler through an adjustable delay medium, and the output end of the second coupler is connected to the detector. an input end, the output end of the detector is connected to the input end of the high-speed oscilloscope, and the output end of the high-speed oscilloscope is connected to the signal processing module; 所述色散介质对所述激光发生器产生的激光信号在时域上进行拉伸,所述第一耦合器将拉伸后的激光信号分成两路,其中一路激光信号依次通过所述环形器、准直器传输给所述衍射器件,该路激光信号经由所述衍射器件产生具有不同衍射路径的衍射光,各个具有不同衍射路径的衍射光通过所述平凸透镜转换为多个平行光,所述多个平行光照射到所述待测样品的不同位置处,所述待测样品的对应位置在接收到平行光后产生反射光,且该对应位置处的反射率被编码到所述反射光的光谱中,所述反射光沿着原传输路径,依次通过所述平凸透镜、衍射器件和准直器传输给所述环形器;所述环形器将所述反射光传输给所述第二耦合器;The dispersive medium stretches the laser signal generated by the laser generator in the time domain, and the first coupler divides the stretched laser signal into two paths, wherein one laser signal passes through the circulator, The collimator is transmitted to the diffractive device, and the laser signal of this route generates diffracted light with different diffraction paths through the diffractive device, and each diffracted light with different diffraction paths is converted into a plurality of parallel lights through the plano-convex lens, and the Multiple parallel lights irradiate different positions of the sample to be tested, the corresponding position of the sample to be tested generates reflected light after receiving the parallel light, and the reflectivity at the corresponding position is encoded into the reflected light. In the spectrum, the reflected light is transmitted to the circulator through the plano-convex lens, the diffraction device and the collimator in sequence along the original transmission path; the circulator transmits the reflected light to the second coupler ; 所述可调延迟介质对所述第一耦合器分成的另一路激光信号进行延迟处理,以与返回的所述反射光进行光程匹配,延迟处理后的该另一路激光信号作为参考光被传输给所述第二耦合器;所述反射光与参考光在所述第二耦合器处发生干涉,产生反射光干涉信号,所述探测器对所述反射光干涉信号进行探测,生成电信号;所述高速示波器对所述电信号进行模数转换,生成数字信号;The adjustable delay medium performs delay processing on another laser signal divided by the first coupler to match the optical path of the returned reflected light, and the delayed laser signal is transmitted as a reference light to the second coupler; the reflected light and the reference light interfere at the second coupler to generate a reflected light interference signal, and the detector detects the reflected light interference signal to generate an electrical signal; The high-speed oscilloscope performs analog-to-digital conversion on the electrical signal to generate a digital signal; 所述信息处理模块根据所述数字信号的光谱强度,来确定所述待测样品在对应位置处的反射率,从而确定该对应位置处的表面信息,并且对所述数字信号进行傅里叶变化,根据傅里叶变化后数字信号的自由光谱范围,来确定所述待测样品在对应位置处的深度信息。The information processing module determines the reflectivity of the sample to be tested at the corresponding position according to the spectral intensity of the digital signal, so as to determine the surface information at the corresponding position, and performs Fourier transformation on the digital signal. , and according to the free spectral range of the digital signal after Fourier transformation, the depth information of the sample to be tested at the corresponding position is determined. 2.根据权利要求1所述的同时获得深度和表面信息的超快显微成像系统,其特征在于,还包括步进电机,设各个平行光所在的同一平面为第一平面,X轴位于该第一平面上且与各个平行光垂直,Z轴与各个平行光平行,Y轴同时垂直于该X轴和Z轴,所述待测样品位于各个平行光中至少部分平行光的正下方,以使对应平行光对所述待测样品进行X轴方向上的线扫描,所述步进电机带动所述待测样品沿着所述Y轴方向移动,从而对所述待测样品进行X-Y两个维度的面扫描。2. The ultrafast microscopic imaging system for simultaneously obtaining depth and surface information according to claim 1, further comprising a stepper motor, setting the same plane where each parallel light is located as the first plane, and the X-axis is located in the first plane. On the first plane and perpendicular to each parallel light, the Z axis is parallel to each parallel light, the Y axis is perpendicular to the X axis and the Z axis at the same time, and the sample to be tested is located directly below at least some of the parallel lights in each parallel light, to Make the corresponding parallel light perform line scanning on the sample to be tested in the X-axis direction, and the stepper motor drives the sample to be tested to move along the Y-axis direction, so that the sample to be tested is X-Y two A face scan of the dimension. 3.根据权利要求1或2所述的同时获得深度和表面信息的超快显微成像系统,其特征在于,还包括光放大器,所述色散介质通过所述光放大器与所述第一耦合器的输入端连接。3. The ultrafast microscopic imaging system for simultaneously obtaining depth and surface information according to claim 1 or 2, characterized in that it further comprises an optical amplifier, and the dispersive medium communicates with the first coupler through the optical amplifier. input connection. 4.根据权利要求3所述的同时获得深度和表面信息的超快显微成像系统,其特征在于,还包括偏振控制器,所述环形器的第三端通过所述偏振控制器与所述第二耦合器的第二输入端连接。4 . The ultrafast microscopic imaging system for simultaneously obtaining depth and surface information according to claim 3 , further comprising a polarization controller, and the third end of the circulator communicates with the circulator through the polarization controller. 5 . The second input of the second coupler is connected. 5.根据权利要求1所述的同时获得深度和表面信息的超快显微成像系统,其特征在于,所述激光信号的一个周期内包括多个具有不同波长的光谱成本。5 . The ultrafast microscopic imaging system for simultaneously obtaining depth and surface information according to claim 1 , wherein one cycle of the laser signal includes a plurality of spectral costs with different wavelengths. 6 . 6.根据权利要求1或5所述的同时获得深度和表面信息的超快显微成像系统,其特征在于,所述激光发生器为超快激光器,所述激光信号的光谱范围为十几纳米级,脉冲重复频率大于兆赫兹。6. The ultrafast microscopic imaging system for simultaneously obtaining depth and surface information according to claim 1 or 5, wherein the laser generator is an ultrafast laser, and the spectral range of the laser signal is more than ten nanometers level, the pulse repetition frequency is greater than megahertz. 7.根据权利要求1所述的同时获得深度和表面信息的超快显微成像系统,其特征在于,所述可调延迟介质根据波长大小,对所述激光信号中具有不同波长的光谱成分分别进行延迟处理,以实现延迟处理后的光谱成分与返回的反射光之间的光程匹配。7 . The ultrafast microscopic imaging system for simultaneously obtaining depth and surface information according to claim 1 , wherein the tunable retardation medium has different wavelengths for spectral components of the laser signal with different wavelengths according to the wavelength. 8 . Delay processing is performed to achieve optical path matching between the spectral components after delay processing and the returned reflected light. 8.根据权利要求1所述的同时获得深度和表面信息的超快显微成像系统,其特征在于,所述系统的视场大小由衍射器件的色散能力,显微物镜的焦距和激光信号光谱带宽共同决定。8. The ultrafast microscopic imaging system for simultaneously obtaining depth and surface information according to claim 1, wherein the field of view of the system is determined by the dispersion capability of the diffractive device, the focal length of the microscope objective and the laser signal spectrum Bandwidth is determined jointly. 9.根据权利要求1所述的同时获得深度和表面信息的超快显微成像系统,其特征在于,所述系统的波长分辨能力由以下几个因素决定:一是色散介质的色散能力,二是色散傅里叶变换(DFT)的光谱分辨能力,三是探测器、高速示波器的带宽决定的光谱分辨能力,系统最终的光谱分辨能力由以上三个参数中最大的决定。9. The ultrafast microscopic imaging system for simultaneously obtaining depth and surface information according to claim 1, wherein the wavelength resolution capability of the system is determined by the following factors: first, the dispersion capability of the dispersive medium, and second It is the spectral resolution capability of the Dispersive Fourier Transform (DFT), and the third is the spectral resolution capability determined by the bandwidth of the detector and the high-speed oscilloscope. The final spectral resolution capability of the system is determined by the largest of the above three parameters. 10.根据权利要求2所述的同时获得深度和表面信息的超快显微成像系统,其特征在于,所述系统的成像帧率由光源的脉冲频率决定,通常超快激光的脉冲频率大于兆赫兹;成像的有效帧率还取决于待测样品在Y轴的移动速度;图像的像素点由激光信号的光谱宽度,色散介质的色散系数和高速示波器的采样率决定。10. The ultrafast microscopic imaging system for simultaneously obtaining depth and surface information according to claim 2, wherein the imaging frame rate of the system is determined by the pulse frequency of the light source, and generally the pulse frequency of the ultrafast laser is greater than megapixels. Hertz; the effective frame rate of imaging also depends on the moving speed of the sample to be tested in the Y-axis; the pixel points of the image are determined by the spectral width of the laser signal, the dispersion coefficient of the dispersive medium and the sampling rate of the high-speed oscilloscope.
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