Nanowire imaging device and group refractive index measurement method

Abstract

The present invention provides a nanowire imaging device and a group refractive index measurement method. In the device, a femtosecond laser light source is optically connected to a microscope objective lens, so that the microscope objective lens focuses the excitation light of the femtosecond laser light source on a nanowire sample on a sample stage, and uses the excitation light as pump light to excite the nanowire sample, so that the nanowire sample generates lasing and radiates coherent outgoing light; and a first beam splitter is optically connected to the microscope objective lens, so that the outgoing light collected by the microscope objective lens is divided into a first beam of light and a second beam of light, and a second reflector for reflecting the second beam of light is arranged on a sliding component, so that the second reflector can move in a direction away from or close to the first beam splitter, thereby realizing the control of the optical path difference between the first beam of light and the second beam of light, so that the first imaging device obtains overlapping imaging with different delay times, realizes signal resolution on a time scale, meets the detection requirements of the light pulse generation and transmission process, and thus provides support for group refractive index measurement.

Description

Technical Field

[0001] The present invention relates to the field of optical measurement technology, and in particular to a nanowire imaging device, a group refractive index measurement method, a group refractive index measurement device, an electronic device and a storage medium. Background Art

[0002] With the rapid development of information technology, fields such as fiber optic communication and optical computing have also developed rapidly. In optoelectronic fields such as fiber optic communication and optical computing, it is extremely important to change the group refractive index of the medium and control the generation of slow light. Slow light refers to the physical phenomenon that the group velocity of light waves slows down and is less than the speed of light in a vacuum when propagating in a medium. Therefore, in order to better generate the required slow light, it is necessary to measure the group refractive index of the medium.

[0003] At present, the group refractive index is calculated by detecting the time delay of light reaching the detector after passing through the medium. However, due to the limitations of the pulse width of the light used and the time resolution limit of the detector, this measurement method can only be applied to the measurement of macroscopic systems, and it is difficult to measure the group refractive index of media below the micro-nano scale. For the nanowire system, a beam of laser light with a photon energy higher than the material band gap is used to irradiate one end of the nanowire sample to excite it to generate radiation, and the spectral signal is collected at the other end of the nanowire to extract the nanowire cavity mode oscillation information to measure the group refractive index. However, the nanowire imaging device uses continuous light as the excitation light source, which cannot achieve signal resolution on a time scale, and thus cannot meet the detection requirements of the light pulse generation and transmission process, and thus cannot measure the group refractive index. Summary of the invention

[0004] The present invention provides a nanowire imaging device, a group refractive index measurement method, a group refractive index measurement device, an electronic device and a storage medium, which are used to solve the defects in the above-mentioned prior art and realize the group refractive index measurement of nanowires.

[0005] The present invention provides a nanowire imaging device, comprising: a sample stage, a femtosecond laser light source, a microscope objective lens, an interferometer and a first imaging device, wherein the interferometer comprises a first beam splitter, a first reflector, a sliding assembly and a second reflector;

[0006] The sample stage is used to place the nanowire sample to be measured;

[0007] The femtosecond laser light source is optically connected to the microscope objective lens, the microscope objective lens is used to focus the excitation light of the femtosecond laser light source on the nanowire sample, and the microscope objective lens is also used to collect the outgoing light of the nanowire sample, the outgoing light is the coherent light emitted after the nanowire sample is lased by the excitation light;

[0008] The first beam splitter is optically connected to the microscope objective lens, and the first beam splitter is used to split the emitted light into a first beam of light and a second beam of light;

[0009] The first reflector is optically connected to the first beam splitter, and the first reflector is used to reflect the first beam of light to the first beam splitter;

[0010] The second reflector is optically connected to the first beam splitter, the second reflector is used to reflect the second light beam to the first beam splitter, the second reflector is arranged on the sliding assembly, and the sliding assembly is used to move the second reflector in a direction away from or close to the first beam splitter;

[0011] The first imaging device is optically connected to the first beam splitter so that the reflected first beam of light is transmitted to the first imaging device and the reflected second beam of light is transmitted to the first imaging device, so that the first imaging device can obtain overlapping images of the nanowire sample.

[0012] A nanowire imaging device according to the present invention further includes: a filter;

[0013] The first beam splitter is optically connected to the microscope objective lens via the optical filter;

[0014] The microscope objective is also used to collect reflected light reflected by the nanowire sample, and the filter is used to block the reflected light and transmit the emitted light.

[0015] A nanowire imaging device according to the present invention further includes: a spectrometer, a foldable mirror and a controller;

[0016] The controller is used to control the foldable mirror so that the filter is optically connected to the first beam splitter, or the filter is optically connected to the spectrometer;

[0017] When the optical filter is optically connected to the spectrometer, the spectrometer is used to detect wavelength information of signal light, and the signal light is light filtered by the optical filter;

[0018] The controller is used to adjust the passing wavelength of the filter based on the wavelength information.

[0019] According to a nanowire imaging device provided by the present invention, the interferometer further comprises: a telephoto lens;

[0020] The first imaging device is optically connected to the first beam splitter through the telephoto lens;

[0021] The telephoto lens is used to converge the reflected first light beam and the reflected second light beam onto the first imaging device.

[0022] According to a nanowire imaging device provided by the present invention, the second reflector is a hollow mirror, the hollow mirror comprises a first mirror and a second mirror, and the mirror angle between the first mirror and the second mirror is 90 degrees;

[0023] The first mirror is used to reflect the second light beam to the second mirror, and the second mirror is used to reflect the second light beam reflected by the first mirror to the first beam splitter.

[0024] A nanowire imaging device according to the present invention further includes: a second beam splitter;

[0025] The femtosecond laser light source is optically connected to the microscope objective lens through the second beam splitter, so that the excitation light is transmitted to the microscope objective lens;

[0026] The first beam splitter is optically connected to the microscope objective lens through the second beam splitter, so that the output light is transmitted to the first beam splitter.

[0027] A nanowire imaging device according to the present invention further includes: an illumination light source and a third beam splitter;

[0028] The illumination light source is optically connected to the microscope objective lens through the third beam splitter, so that the illumination light of the illumination light source is transmitted to the microscope objective lens, and the microscope objective lens is also used to focus the illumination light on the nanowire sample;

[0029] The first beam splitter is optically connected to the microscope objective lens through the third beam splitter, so that the output light is transmitted to the first beam splitter.

[0030] A nanowire imaging device according to the present invention further includes: a second imaging device and a controller;

[0031] The second imaging device is optically connected to the microscope objective lens so that the emitted light is transmitted to the second imaging device, so that the second imaging device can obtain sample imaging of the nanowire sample;

[0032] The sample stage is a movable stage capable of three-dimensional displacement, and the controller is used to control the movement of the sample stage based on the sample imaging so as to perform imaging and focusing on the nanowire sample.

[0033] The present invention also provides a method for measuring a group refractive index using any of the nanowire imaging devices described above, comprising:

[0034] In a current imaging round, acquiring position information of the sliding component, and determining a delay time of the current imaging round based on the position information;

[0035] Acquire overlapping images obtained by the first imaging device in the current imaging round;

[0036] In the case where the current imaging round is not the last imaging round, controlling the sliding component to move to a position of a next imaging round, and using the next imaging round as the current imaging round to obtain a plurality of overlapping imagings with different delay times;

[0037] Determining interference fringe intensity distribution information based on the overlapping imaging of the plurality of different delay times;

[0038] The group velocity is determined based on the interference fringe intensity distribution information, the delay time of the overlapping images of the multiple different delay times and the length of the nanowire sample, and the group refractive index of the nanowire sample is determined based on the group velocity.

[0039] According to a group refractive index measurement method provided by the present invention, when the nanowire imaging device includes a filter, a spectrometer and a foldable mirror, before acquiring the overlapping imaging obtained by the first imaging device in the current imaging round, the method further includes:

[0040] Controlling the foldable mirror to connect the filter to the spectrometer in an optical path;

[0041] adjusting the passing wavelength of the filter based on the wavelength information detected by the spectrometer;

[0042] The foldable mirror is controlled to connect the filter with the first beam splitter in an optical path.

[0043] According to a group refractive index measurement method provided by the present invention, when the nanowire imaging device includes a second imaging device, before acquiring the overlapping imaging obtained by the first imaging device in the current imaging round, the method further includes:

[0044] Acquiring sample imaging obtained by the second imaging device;

[0045] determining a movement mode based on imaging of the sample;

[0046] Based on the movement mode, the movement of the sample stage is controlled.

[0047] The present invention also provides a group refractive index measurement device implemented by using any of the above-mentioned nanowire imaging devices, comprising:

[0048] An information acquisition module, used to acquire position information of the sliding component in a current imaging round, and determine a delay time of the current imaging round based on the position information;

[0049] An imaging acquisition module, used for acquiring overlapping images acquired by the first imaging device in the current imaging round;

[0050] A component control module, used for controlling the movement of the sliding component to move the sliding component to a position of a next imaging round when the current imaging round is not the last imaging round, and taking the next imaging round as the current imaging round to obtain a plurality of overlapping imagings with different delay times;

[0051] An information determination module, used to determine the interference fringe intensity distribution information based on the overlapping imaging of the plurality of different delay times;

[0052] The group refractive index determination module is used to determine the group velocity based on the interference fringe intensity distribution information, the delay time of the overlapping imaging of the multiple different delay times and the length of the nanowire sample, and determine the group refractive index of the nanowire sample based on the group velocity.

[0053] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, any of the group refractive index measurement methods described above is implemented.

[0054] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the group refractive index measurement method as described above is implemented.

[0055] The nanowire imaging device, group refractive index measurement method, group refractive index measurement device, electronic device and storage medium provided by the present invention are characterized in that a femtosecond laser light source is optically connected to a microscope objective lens so that the microscope objective lens focuses the excitation light of the femtosecond laser light source on the nanowire sample on the sample stage, that is, the excitation light is focused to the surface of the nanowire sample through the microscope objective lens to serve as pump light to excite the nanowire sample, thereby causing the nanowire sample to generate laser light and radiate coherent outgoing light; and a first beam splitter is optically connected to the microscope objective lens so as to divide the outgoing light collected by the microscope objective lens into a first beam of light and a second beam of light, and is used for A second reflector reflecting the second light beam is arranged on the sliding assembly, so that the second reflector can move in a direction away from or close to the first beam splitter, thereby realizing the control of the optical path difference between the first light beam and the second light beam, so that the first imaging device obtains overlapping imaging with different delay times. Since the emergent light is a coherent laser, the intensity distribution information of the interference fringe can be determined based on the overlapping imaging with multiple different delay times, so as to realize the detection of light pulse signal changes on a time scale, that is, to realize signal resolution on a time scale, meet the detection requirements of the light pulse generation and transmission process, and thus provide support for the group refractive index measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0057] Figure 1 This is one of the structural schematic diagrams of the nanowire imaging device provided by the present invention;

[0058] Figure 2 The second structural schematic diagram of the nanowire imaging device provided by the present invention;

[0059] Figure 3 A schematic diagram of a flow chart of a group refractive index measurement method provided by the present invention;

[0060] Figure 4 A schematic diagram of the structure of a group refractive index measuring device provided by the present invention;

[0061] Figure 5 This is a schematic structural diagram of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0064] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0065] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0066] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0067] With the rapid development of information technology, fields such as fiber-optic communication and optical computing have also developed rapidly. In optoelectronic fields such as fiber-optic communication and optical computing, it is extremely important to change the group refractive index of the medium and control the generation of slow light. That is, light speed control technology has become a research hotspot in the optoelectronic field. Specifically, controlling the group speed to slow down is conducive to improving the signal delay adjustment efficiency of the optical buffer in all-optical communication and realizing controllable caching; changing the group refractive index of the medium and controlling the generation of slow light can also improve the detection sensitivity of optical sensors (such as interferometers, optical gyroscopes, etc.). Therefore, slow light technology has important application value in the optoelectronic field. Among them, slow light refers to the physical phenomenon that the group velocity of light waves slows down and is less than the speed of light in a vacuum when propagating in a medium. Therefore, in order to better generate the required slow light, it is necessary to measure the group refractive index of the medium.

[0068] At present, the group refractive index is calculated by detecting the time delay of light reaching the detector after passing through the medium. However, due to the limitations of the pulse width of the light used and the time resolution limit of the detector, this measurement method can only be applied to the measurement of macroscopic systems, and it is difficult to measure the group refractive index of media below the micro-nano scale. For the nanowire system, a beam of laser light with a photon energy higher than the material band gap is used to irradiate one end of the nanowire sample to excite it to generate radiation, and the spectral signal is collected at the other end of the nanowire to extract the nanowire cavity mode oscillation information to measure the group refractive index. However, the nanowire imaging device uses continuous light as the excitation light source, which cannot achieve signal resolution on a time scale, and thus cannot meet the detection requirements of the light pulse generation and transmission process, and thus cannot measure the group refractive index. Therefore, how to measure the group refractive index of nanowire samples is an urgent problem to be solved.

[0069] In view of the above problems, the present invention proposes the following embodiments. In order to measure the group refractive index of the nanowire sample, it is necessary to display the output light of the nanowire sample on the imaging plane, and then image the nanowire sample. In order to directly observe the time scale of the light pulse transmission in the nanowire sample, the embodiment of the first aspect of the present invention proposes a nanowire imaging device, which detects the propagation of the light pulse in the nanowire sample by means of laser coherent analysis, so as to intuitively observe the time scale process of the pulse, so as to provide support for the measurement of the group refractive index of the nanowire sample.

[0070] Figure 1 One of the structural schematic diagrams of the nanowire imaging device provided by the present invention is as follows: Figure 1 As shown, the nanowire imaging device includes: a sample stage, a femtosecond laser light source, a microscope objective, an interferometer and a first imaging device, wherein the interferometer includes a first beam splitter, a first reflector, a sliding assembly and a second reflector.

[0071] The sample stage is used to place the nanowire sample to be measured.

[0072] The nanowire sample is a medium for which group refractive index measurement is to be performed, and the nanowire sample is a semiconductor nanowire, so that lasing can be achieved in the semiconductor nanowire to radiate coherent laser light.

[0073] In one embodiment, the sample stage is a movable stage capable of three-dimensional displacement, so that the nanowire sample can be moved in three-dimensional space, thereby completing imaging and focusing of the nanowire sample.

[0074] The femtosecond laser light source is optically connected to the microscope objective lens, and the microscope objective lens is used to focus the excitation light of the femtosecond laser light source on the nanowire sample. The microscope objective lens is also used to collect the exit light of the nanowire sample. The exit light is coherent light emitted after the nanowire sample is lasered by the excitation light.

[0075] Among them, the femtosecond laser light source is used to generate femtosecond laser, and the excitation light it emits is used as pump light to excite the nanowire sample.

[0076] It should be noted that the group refractive index measurement method of the nanowire sample is to use the cavity mode distribution formed by itself for calculation. Specifically, the two end faces of the nanowire sample form a Fabry-Perot cavity along the axial direction. The radiated light propagates back and forth in the nanowire sample, and radiates outward through the end face when it propagates to the end face. Due to the mode selection effect of the resonant cavity, the light emitted from the end face has an oscillation characteristic in the wavelength range. By calculating the interval of the oscillation mode and combining the nanowire length, the corresponding group refractive index is obtained. Considering that when the radial length of the nanowire sample is close to the wavelength range, the oscillation mode in the nanowire sample is limited, making it difficult to accurately measure its group refractive index in this measurement method. Based on this, the light source of the excitation light is a femtosecond laser light source. And by exciting the nanowire sample to generate a laser pulse by a femtosecond laser, time precision detection at the femtosecond scale can be achieved, that is, spatial precision detection at the nanometer scale can be achieved.

[0077] The outgoing light is the excitation light that is focused onto the surface of the nanowire sample through the microscope objective lens to excite the nanowire sample, that is, after the power density reaches the lasing threshold, the nanowire sample is lased and radiates coherent laser light. The outgoing light is collected by the microscope objective lens and enters the optical path of the nanowire imaging device.

[0078] The first beam splitter is optically connected to the microscope objective lens, and the first beam splitter is used to split the emitted light into a first beam of light and a second beam of light.

[0079] The first beam splitter can reflect and transmit the outgoing light. In one embodiment, the first beam of light can be the outgoing light of transmission, and the second beam of light can be the outgoing light of reflection. In another embodiment, the first beam of light can be the outgoing light of reflection, and the second beam of light can be the outgoing light of transmission.

[0080] The first reflector is optically connected to the first beam splitter, and the first reflector is used to reflect the first beam of light to the first beam splitter.

[0081] Specifically, the first beam of light passes through the first reflector and returns to the first beam splitter along the original path.

[0082] The second reflector is optically connected to the first beam splitter, and is used to reflect the second light beam to the first beam splitter. The second reflector is arranged on the sliding assembly, and the sliding assembly is used to move the second reflector in a direction away from or close to the first beam splitter.

[0083] Specifically, the second light beam passes through the second reflector and returns to the first beam splitter along the original path.

[0084] It can be understood that the optical path difference between the first beam and the second beam can be controlled by the sliding component, so as to detect the change of the optical pulse signal on a time scale, that is, to achieve signal resolution on a time scale, thereby meeting the detection requirements of the optical pulse generation and transmission process. And by exciting the nanowire sample with a femtosecond laser to generate a laser pulse, combined with the sliding component to control the delay time, it is possible to achieve femtosecond-scale time precision detection, that is, nanometer-scale spatial precision detection.

[0085] In one embodiment, the sliding component may be an electrically controlled displacement stage (time delay line). Specifically, the sliding component is a precision piezoelectric displacement stage, and the step length of each movement can be set according to actual needs. For example, the minimum step length is 50 nm, so that a minimum time delay of 0.33 fs can be achieved. Based on this, the need for precise control of the time delay required for interference fringe detection is met.

[0086] The first imaging device is optically connected to the first beam splitter so that the reflected first beam of light is transmitted to the first imaging device and the reflected second beam of light is transmitted to the first imaging device, so that the first imaging device can obtain overlapping images of the nanowire sample.

[0087] The first imaging device is used to receive the optical signal in the optical path for spatial imaging. Specifically, the first light beam and the second light beam are converged on the photosensitive plane of the first imaging device to achieve overlapping imaging of the outgoing light. The first imaging device can be a CMOS (Complementary Metal Oxide Semiconductor) camera, and the embodiment of the present invention does not specifically limit the first imaging device.

[0088] The overlapping imaging can be the overlapping of the left ends of the nanowire samples, or the overlapping of the right ends of the nanowire samples. Different overlapping modes can be achieved by adjusting the imaging positions of the first beam of light and the second beam of light on the first imaging device, which is not limited in the embodiment of the present invention. Since the emitted light of the nanowire sample reaches the photosensitive plane of the first imaging device at the same time through the first beam of light and the second beam of light, coherent fringes of light and dark appear in the overlapping imaging.

[0089] In addition, by controlling the position of the sliding assembly, the first imaging device can obtain overlapping imaging with different delay times.

[0090] In one embodiment, if the first light beam is transmitted output light and the second light beam is reflected output light, the reflected first light beam is reflected and transmitted to the first imaging device through the first beam splitter, and the reflected second light beam is transmitted and transmitted to the first imaging device through the first beam splitter.

[0091] In another embodiment, if the first light beam is reflected output light and the second light beam is transmitted output light, the reflected first light beam is transmitted through the first beam splitter to the first imaging device, and the reflected second light beam is reflected through the first beam splitter to the first imaging device.

[0092] In the nanowire imaging device provided by the embodiment of the present invention, a femtosecond laser light source is optically connected to a microscope objective lens so that the microscope objective lens focuses the excitation light of the femtosecond laser light source on the nanowire sample on the sample stage, that is, the excitation light is focused to the surface of the nanowire sample through the microscope objective lens to serve as pump light to excite the nanowire sample, thereby causing the nanowire sample to generate lasing and radiate coherent outgoing light; and a first beam splitter is optically connected to the microscope objective lens so as to divide the outgoing light collected by the microscope objective lens into a first beam of light and a second beam of light, and a second reflector for reflecting the second beam of light is provided. The sliding assembly is used to enable the second reflector to move in a direction away from or close to the first beam splitter, thereby realizing the control of the optical path difference between the first light beam and the second light beam, so that the first imaging device can obtain overlapping imaging with different delay times. Since the emergent light is a coherent laser, the intensity distribution information of the interference fringe can be determined based on the overlapping imaging with multiple different delay times, so as to realize the detection of light pulse signal changes on a time scale, that is, to realize signal resolution on a time scale, meet the detection requirements of the light pulse generation and transmission process, and thus provide support for the group refractive index measurement.

[0093] Based on the above embodiment, the nanowire imaging device further includes: a filter.

[0094] The first beam splitter is optically connected to the microscope objective lens via the optical filter.

[0095] Among them, the filter is used to achieve the wavelength selection of the output light of the nanowire sample, that is, to filter the optical signal. Specifically, the filter has a passing wavelength parameter. Only when the wavelength of the optical signal is within the passing wavelength of the filter, the optical signal is allowed to pass through the filter, otherwise the optical signal is blocked. Based on this, the optical signal other than the output light of the nanowire sample can be blocked, and only the output light is allowed to pass, thereby ensuring the accuracy of the overlapping imaging. Furthermore, the passing wavelength of the filter can be updated, so that the wavelength required for detection can be selected according to actual needs.

[0096] In one embodiment, the optical filter is a bandpass filter. In another embodiment, the optical filter is composed of a combination of a low-pass filter and a high-pass filter.

[0097] Specifically, one end of the filter is connected to the optical path of the first beam splitter, and the other end of the filter is connected to the optical path of the microscope objective.

[0098] The microscope objective is also used to collect reflected light reflected by the nanowire sample, and the filter is used to block the reflected light and transmit the emitted light.

[0099] The reflected light reflected by the nanowire sample is the light reflected by the excitation light focused on the nanowire sample.

[0100] In one embodiment, the microscope objective is also used to collect reflected light reflected by the sample stage (e.g., substrate), and the filter is also used to block the reflected light reflected by the sample stage. In one embodiment, the filter is also used to block the light divided by the excitation light after passing through the second beam splitter. In one embodiment, the filter is also used to block the light divided by the illumination light source after passing through the third beam splitter.

[0101] In one embodiment, the filter is optically connected to the microscope objective lens via a second beam splitter. In one embodiment, the filter is optically connected to the microscope objective lens via a third beam splitter. In one embodiment, the filter is optically connected to the first beam splitter via a foldable mirror.

[0102] The nanowire imaging device provided by the embodiment of the present invention can ensure that other light signals except the outgoing light are blocked by setting a filter in the middle of the light path between the first beam splitter and the microscope objective, and only allow the outgoing light to pass, thereby ensuring the accuracy of overlapping imaging and ultimately improving the accuracy of group refractive index measurement.

[0103] Based on any of the above embodiments, the nanowire imaging device further includes: a spectrometer, a foldable mirror and a controller.

[0104] The controller is used to control the foldable mirror so that the optical filter is optically connected to the first beam splitter, or the optical filter is optically connected to the spectrometer.

[0105] The spectrometer is used to determine the spectrum information of the collected optical signal. Specifically, the optical signal enters the spectrometer for spectral detection to determine the wavelength information.

[0106] The foldable mirror can be controlled in two states. The first state: the filter is connected to the optical path of the first beam splitter, and the filter is disconnected from the optical path of the spectrometer. The second state: the filter is disconnected from the optical path of the first beam splitter, and the filter is connected to the optical path of the spectrometer.

[0107] When the optical filter is optically connected to the spectrometer, the spectrometer is used to detect wavelength information of signal light, and the signal light is light filtered by the optical filter.

[0108] The controller is used to adjust the passing wavelength of the filter based on the wavelength information.

[0109] Specifically, based on the wavelength information, the passing wavelength of the filter is continuously changed until the wavelength information meets the requirements, and the passing wavelength of the filter is stopped, so that the filter can pass only the outgoing light as much as possible. Further, after determining the passing wavelength of the filter, the foldable mirror is controlled to connect the filter with the first beam splitter in an optical path, so that the outgoing light enters the interferometer.

[0110] In one embodiment, the foldable mirror is optically connected to the spectrometer via a fourth beam splitter.

[0111] The nanowire imaging device provided by the embodiment of the present invention can control the foldable mirror to connect the filter to the optical path of the spectrometer when it is necessary to update the passing wavelength of the filter, so that the wavelength information of the signal light filtered by the filter is detected by the spectrometer, and then the passing wavelength of the filter is adjusted based on the wavelength information, so that the required detection wavelength can be selected, thereby ensuring that other light signals except the outgoing light are blocked and only the outgoing light is allowed to pass, thereby ensuring the accuracy of overlapping imaging and ultimately improving the accuracy of group refractive index measurement.

[0112] Based on any of the above embodiments, the interferometer further includes: a telephoto lens.

[0113] The first imaging device is optically connected to the first beam splitter through the telephoto lens.

[0114] The telephoto lens is used to focus the input optical signal. Specifically, the telephoto lens can realize the reciprocal conversion of the object phase between the real space phase and the Fourier phase.

[0115] The telephoto lens is used to converge the reflected first light beam and the reflected second light beam onto the first imaging device.

[0116] Specifically, the two beams of light respectively reflected and transmitted by the first beam splitter are converged on the photosensitive plane of the first imaging device through the telephoto lens, thereby achieving overlapping imaging of the outgoing light.

[0117] The nanowire imaging device provided by the embodiment of the present invention arranges a telephoto lens in the middle of the optical path of the first imaging device and the first beam splitter, thereby converging the reflected first beam of light and the reflected second beam of light on the first imaging device, thereby better realizing the overlapping of the imaging of the outgoing light, further improving the accuracy of the overlapping imaging, and ultimately further improving the accuracy of the group refractive index measurement.

[0118] Based on any of the above embodiments, the second reflector is a hollow mirror, which includes a first mirror and a second mirror, and the mirror angle between the first mirror and the second mirror is 90 degrees; the first mirror is used to reflect the second beam of light to the second mirror, and the second mirror is used to reflect the second beam of light reflected by the first mirror to the first beam splitter.

[0119] The first mirror is a reflector, the mirror surface of the first mirror faces the second light beam, and is used to reflect the second light beam. The second mirror is a reflector, the mirror surface of the second mirror faces the second light beam, and is used to reflect the second light beam.

[0120] In a specific embodiment, the incident angle between the second light beam and the mirror surface of the first mirror is 45 degrees, so that the second light beam reflected by the hollow mirror is reflected back to the first beam splitter.

[0121] In the nanowire imaging device provided by an embodiment of the present invention, the second reflector is a hollow mirror, and the mirror angle between the first mirror and the second mirror is 90 degrees, ensuring that the second light beam reflected by the first mirror is parallel to the optical path of the second light beam incident to the first mirror, thereby ensuring that the position of the optical signal will not shake, that is, only a time delay is generated, thereby improving the accuracy of overlapping imaging, and ultimately further improving the accuracy of group refractive index measurement.

[0122] Based on any of the above embodiments, the nanowire imaging device further includes: a second beam splitter.

[0123] The femtosecond laser light source is optically connected to the microscope objective lens through the second beam splitter, so that the excitation light is transmitted to the microscope objective lens.

[0124] The first beam splitter is optically connected to the microscope objective lens through the second beam splitter, so that the output light is transmitted to the first beam splitter.

[0125] The second beam splitter can reflect and transmit the excitation light of the femtosecond laser light source. In one embodiment, the second beam splitter reflects the excitation light to the microscope objective lens and transmits the outgoing light. In another embodiment, the second beam splitter transmits the excitation light to the microscope objective lens and reflects the outgoing light.

[0126] One end of the second beam splitter is connected to the microscope objective optical path, and the other end of the second beam splitter is connected to the first beam splitter optical path, and the second beam splitter is optically connected to the first beam splitter. In one embodiment, the second beam splitter is optically connected to the first beam splitter through a filter, based on which the filter can block the excitation light passing through the second beam splitter. In one embodiment, the second beam splitter is optically connected to the first beam splitter through a third beam splitter.

[0127] The nanowire imaging device provided by the embodiment of the present invention has a second beam splitter disposed in the middle of the optical path between the femtosecond laser light source and the microscope objective lens, which can transmit the excitation light to the microscope objective lens and transmit the output light to the first beam splitter, thereby better managing the optical path and ensuring the accuracy of overlapping imaging, and ultimately further improving the accuracy of group refractive index measurement.

[0128] Based on any of the above embodiments, the nanowire imaging device further includes: an illumination light source and a third beam splitter.

[0129] The illumination light source is optically connected to the microscope objective through the third beam splitter, so that the illumination light of the illumination light source is transmitted to the microscope objective, and the microscope objective is also used to focus the illumination light on the nanowire sample.

[0130] The first beam splitter is optically connected to the microscope objective lens through the third beam splitter, so that the output light is transmitted to the first beam splitter.

[0131] The illumination light source is used to provide illumination for the nanowire sample, and the illumination light source is preferably a white light source, but can also be a light source of other colors.

[0132] The third beam splitter can reflect and transmit the illumination light of the illumination light source. In one embodiment, the third beam splitter reflects the illumination light to the microscope objective lens and transmits the outgoing light. In another embodiment, the third beam splitter transmits the illumination light to the microscope objective lens and reflects the outgoing light.

[0133] One end of the third beam splitter is connected to the microscope objective optical path, and the other end of the third beam splitter is connected to the first beam splitter optical path, and the third beam splitter is optically connected to the first beam splitter. In one embodiment, the third beam splitter is optically connected to the first beam splitter through a filter, based on which the filter can block the illumination light passing through the third beam splitter. In one embodiment, the third beam splitter is optically connected to the microscope objective through the second beam splitter. In one embodiment, the third beam splitter is optically connected to the first beam splitter through the second beam splitter.

[0134] The nanowire imaging device provided by the embodiment of the present invention is provided with an illumination light source to provide illumination for the nanowire sample, thereby ensuring the clarity of the overlapping imaging, and ultimately further improving the accuracy of the group refractive index measurement; and a third beam splitter is provided in the middle of the light path between the illumination light source and the microscope objective lens, which can transmit the illumination light to the microscope objective lens and transmit the output light to the first beam splitter, thereby better performing the light path management, ensuring the accuracy of the overlapping imaging, and ultimately further improving the accuracy of the group refractive index measurement.

[0135] Based on any of the above embodiments, the nanowire imaging device further includes: a second imaging device and a controller.

[0136] The second imaging device is optically connected to the microscope objective lens so that the emitted light is transmitted to the second imaging device, so that the second imaging device can obtain sample imaging of the nanowire sample.

[0137] The sample stage is a movable stage capable of three-dimensional displacement, and the controller is used to control the movement of the sample stage based on the sample imaging so as to perform imaging and focusing on the nanowire sample.

[0138] The second imaging device is used to receive the optical signal in the optical path for spatial imaging. Specifically, the outgoing light is converged on the photosensitive plane of the second imaging device to achieve imaging of the outgoing light. The second imaging device may be a CMOS camera, and the embodiment of the present invention does not specifically limit the second imaging device.

[0139] In one embodiment, the second imaging device is optically connected to the microscope objective lens through a filter. In one embodiment, the second imaging device is optically connected to the microscope objective lens through a second beam splitter. In one embodiment, the second imaging device is optically connected to the microscope objective lens through a third beam splitter. In one embodiment, the second imaging device is optically connected to the microscope objective lens through a foldable mirror.

[0140] In one embodiment, the nanowire imaging device further includes: a fourth beam splitter and a spectrometer. The second imaging device is optically connected to the microscope objective lens through the fourth beam splitter so that the output light is transmitted to the second imaging device, and the spectrometer is optically connected to the microscope objective lens through the fourth beam splitter so that the output light is transmitted to the spectrometer.

[0141] The fourth beam splitter can reflect and transmit the outgoing light. In one embodiment, the fourth beam splitter reflects the outgoing light to the second imaging device and transmits the outgoing light to the spectrometer. In another embodiment, the fourth beam splitter transmits the outgoing light to the second imaging device and reflects the outgoing light to the spectrometer.

[0142] One end of the fourth beam splitter is connected to the optical path of the microscope objective, the other end of the fourth beam splitter is connected to the optical path of the second imaging device, and the third end of the fourth beam splitter is connected to the optical path of the spectrometer. In one embodiment, the fourth beam splitter is optically connected to the microscope objective through a filter. In one embodiment, the fourth beam splitter is optically connected to the microscope objective through the second beam splitter. In one embodiment, the fourth beam splitter is optically connected to the microscope objective through the third beam splitter. In one embodiment, the fourth beam splitter is optically connected to the microscope objective through a foldable mirror.

[0143] It can be understood that the provision of the fourth beam splitter can better manage the optical path, ensure the accuracy of overlapping imaging, and ultimately further improve the accuracy of group refractive index measurement.

[0144] The nanowire imaging device provided in an embodiment of the present invention images the outgoing light of the nanowire sample by setting up a second imaging device, thereby controlling the sample stage to move in three dimensions based on the sample imaging to achieve imaging focusing of the nanowire sample, ensure the clarity and accuracy of the overlapping imaging, and ultimately further improve the accuracy of the group refractive index measurement.

[0145] To facilitate understanding of the above embodiments, it should be noted that the propagation of light pulses and the detection of coherent fringes requires that the nanowire sample can achieve coherent laser emission. The end face of the nanowire sample structure and the external medium (generally air) form a Fabry-Perot resonant cavity, which provides an effective gain medium, a low-loss waveguide and strong lateral optical confinement for the axial mode. Using a femtosecond laser pulse as the excitation light, after the excitation power reaches the lasing threshold of the nanowire sample, a coherent lasing light pulse is generated in the nanowire sample. When the lasing light pulse reaches the end face of the nanowire, a part of it is emitted outward through the end face, and the emission signal is collected by the first imaging device through the nanowire imaging device; the other part is reflected by the end face and propagates in the opposite direction in the nanowire sample, and continues to be transmitted and reflected when it reaches the other end face until the pulse intensity is completely attenuated.

[0146] To facilitate understanding of the above embodiments, a specific embodiment is described here. Figure 2 , Figure 2 The second structural schematic diagram of the nanowire imaging device provided by the present invention is as follows: Figure 2 As shown, the nanowire imaging device includes a femtosecond laser (femtosecond laser light source), a microscope objective, an interferometer, a camera 2 (a first imaging device), a filter, a spectrometer, a foldable mirror, a lens (a telephoto lens), a beam splitter 1 (a second beam splitter), a white light source (an illumination light source), a beam splitter 2 (a third beam splitter), a camera 1 (a second imaging device), and a beam splitter 3 (a fourth beam splitter). The interferometer includes a beam splitter 4 (a first beam splitter), a reflector (a first reflector), an electrically controlled displacement stage (a sliding assembly), and a hollow mirror (a second reflector). The microscope objective is used to focus the excitation light of the femtosecond laser on the nanowire sample, and the microscope objective is also used to collect the emitted light of the nanowire sample. The illumination light of the white light source is transmitted to the beam splitter 2 through an optical fiber. The electrically controlled displacement stage can move left and right, so that the hollow mirror moves in a direction away from or close to the beam splitter 4. The controller can be a computer, so as to analyze the interference intensity signal detected by the camera 2 by a computer, and then obtain the interference intensity signal containing time information in combination with the optical path corresponding to the electrically controlled displacement stage.

[0147] Based on the above nanowire imaging device, the present invention also proposes a group refractive index measurement method, which is implemented using the above nanowire imaging device. The execution subject of the group refractive index measurement method can be a controller of the nanowire imaging device, or another terminal device, such as a laptop, desktop computer, tablet computer, smart phone, embedded system, server, etc., which is not limited in the embodiment of the present invention.

[0148] Figure 3 A schematic diagram of the process of measuring the group refractive index provided by the present invention is shown in FIG. Figure 3 As shown, the group refractive index measurement method includes:

[0149] Step 310: acquiring position information of the sliding component in the current imaging round, and determining a delay time of the current imaging round based on the position information.

[0150] It should be noted that in order to obtain overlapping imaging with different delay times, multiple imaging rounds need to be performed. The position of the sliding component in each imaging round is different. Based on this, the delay time in each imaging round is different. Therefore, it is necessary to obtain the delay time of each imaging round.

[0151] Specifically, the delay time corresponding to the location information may be determined based on the location-time mapping relationship. The corresponding delay time may also be calculated by a formula based on the location information. The embodiment of the present invention does not limit this.

[0152] Step 320: Acquire overlapping images obtained by the first imaging device in the current imaging round.

[0153] Overlapping imaging can be obtained by the nanowire imaging device of any of the above embodiments. The specific process of obtaining overlapping imaging can refer to the above embodiments, which will not be described in detail here.

[0154] Step 330, when the current imaging round is not the last imaging round, control the sliding assembly to move to the position of the next imaging round, and use the next imaging round as the current imaging round to obtain overlapping imaging with multiple different delay times.

[0155] It is understandable that after each imaging round, the sliding assembly is controlled to move so that the position of the sliding assembly in each imaging round is different, thereby obtaining overlapping imaging of different imaging rounds, that is, obtaining overlapping imaging with different delay times.

[0156] Step 340: Determine the interference fringe intensity distribution information based on the overlapping imaging of the multiple different delay times.

[0157] Specifically, the interference fringe intensity distribution information is extracted from overlapping images of multiple different delay times.

[0158] Step 350, determining a group velocity based on the interference fringe intensity distribution information, the delay time of the overlapping imaging of the multiple different delay times and the length of the nanowire sample, and determining a group refractive index of the nanowire sample based on the group velocity.

[0159] Specifically, based on the intensity distribution information of the interference fringes, the amplitude corresponding to the interference fringes is obtained by Fourier transform, which represents the coherence intensity of the two light pulses at this time. Since the light pulse emitted by the nanowire sample is reflected back and forth multiple times in the reflection cavity formed by the nanowire itself, it appears as the emission of multiple light pulses on the time scale. From the delay time scale, multiple symmetrically distributed pulse signal peaks can be observed, corresponding to the coherence intensity distribution of the coherent light pulse at time zero and the pulse at any time. By fitting the peak value and intensity distribution of the pulse peak, the dynamic process of the laser pulse moving in the nanowire sample can be obtained, and then the propagation speed of the laser pulse generated by femtosecond laser excitation in the nanowire sample, that is, the group velocity, can be calculated in combination with the length of the nanowire, and then the group refractive index of the nanowire sample can be determined based on the group velocity and the speed of light.

[0160] It should be noted that the real-space imaging detection of the laser light pulses in the nanowire sample is spatially overlapped on the detection plane of the imaging device. The optical path difference of the two paths of light in the interferometer is controlled by adjusting the movement of the sliding component, and the coherence change of the light pulse is collected to obtain the distribution of the interference signal on the time scale. The intensity of the coherent fringes at the corresponding delay time (i.e., at a certain optical path difference position) is extracted from the image through the Fourier transform operation. The time distribution of the coherent intensity is extracted and fitted to obtain the intensity and time distribution of multiple pulse peaks, and the time when the laser pulse reaches the endpoint during multiple propagation processes in the nanowire is obtained.

[0161] In the group refractive index measurement method provided by the embodiment of the present invention, a femtosecond laser light source is optically connected to a microscope objective lens so that the microscope objective lens focuses the excitation light of the femtosecond laser light source on the nanowire sample on the sample stage, that is, the excitation light is focused to the surface of the nanowire sample through the microscope objective lens to serve as pump light to excite the nanowire sample, thereby causing the nanowire sample to generate lasing and radiate coherent outgoing light; and a first beam splitter is optically connected to the microscope objective lens so as to divide the outgoing light collected by the microscope objective lens into a first beam of light and a second beam of light, and a second reflector for reflecting the second beam of light is disposed on a sliding component so that the second reflector can move in a direction away from or close to the first beam splitter, thereby realizing the control of the optical path difference between the first beam of light and the second beam of light, that is, the position information of the sliding component can be obtained in the current imaging round, and the delay time of the current imaging round can be determined based on the position information, thereby obtaining Take the overlapping images obtained by the first imaging device in the current imaging round. When the current imaging round is not the last imaging round, control the sliding component to move to the position of the next imaging round, and use the next imaging round as the current imaging round to obtain multiple overlapping images with different delay times. Since the emitted light is a coherent laser, the interference fringe intensity distribution information can be determined based on the overlapping imaging with multiple different delay times, so as to detect the change of the light pulse signal on the time scale, that is, to achieve signal resolution on the time scale, and meet the detection requirements of the light pulse generation and transmission process. That is, the group velocity can be determined based on the interference fringe intensity distribution information, the delay time of the overlapping imaging with multiple different delay times and the length of the nanowire sample, and the group refractive index of the nanowire sample can be determined based on the group velocity, and finally the group refractive index measurement of the nanowire sample can be achieved.

[0162] Based on any of the above embodiments, when the nanowire imaging device includes a filter, a spectrometer, and a foldable mirror, before the above step 320, the method further includes:

[0163] Controlling the foldable mirror to connect the filter to the spectrometer in an optical path;

[0164] adjusting the passing wavelength of the filter based on the wavelength information detected by the spectrometer;

[0165] The foldable mirror is controlled to connect the filter with the first beam splitter in an optical path.

[0166] Specifically, based on the wavelength information, the passing wavelength of the filter is continuously changed until the wavelength information meets the requirements, and the passing wavelength of the filter is stopped, so that the filter can only pass the outgoing light as much as possible. After the passing wavelength of the filter is determined, the foldable mirror is controlled to connect the filter with the first beam splitter in an optical path, so that the outgoing light enters the interferometer.

[0167] The group refractive index measurement method provided by the embodiment of the present invention can control the foldable mirror to connect the filter to the optical path of the spectrometer when it is necessary to update the passing wavelength of the filter, so that the wavelength information of the signal light filtered by the filter is detected by the spectrometer, and then the passing wavelength of the filter is adjusted based on the wavelength information, so that the wavelength required for detection can be selected, and then it can be ensured that other optical signals except the outgoing light are blocked and only the outgoing light is allowed to pass, thereby ensuring the accuracy of overlapping imaging, and finally improving the accuracy of group refractive index measurement.

[0168] Based on any of the above embodiments, when the nanowire imaging device includes a second imaging device, before the above step 320, the method further includes:

[0169] Acquiring sample imaging obtained by the second imaging device;

[0170] determining a movement mode based on imaging of the sample;

[0171] Based on the movement mode, the movement of the sample stage is controlled.

[0172] Sample imaging can be obtained by using the nanowire imaging device of any of the above embodiments. The specific process of obtaining sample imaging can refer to the above embodiments and will not be described in detail here.

[0173] Specifically, the clarity of the sample imaging is determined, and then the movement mode is determined based on the clarity, and then based on the movement mode, the sample stage is controlled to move in three-dimensional space to perform imaging and focusing on the nanowire sample.

[0174] The nanowire imaging device provided in an embodiment of the present invention images the outgoing light of the nanowire sample by setting up a second imaging device, thereby controlling the sample stage to move in three dimensions based on the sample imaging to achieve imaging focusing of the nanowire sample, ensure the clarity and accuracy of the overlapping imaging, and ultimately further improve the accuracy of the group refractive index measurement.

[0175] In actual applications, pure optical non-destructive detection is achieved by collecting signals through light excitation and imaging devices, avoiding the constraints of the medium environment in which the nanowire samples are located, and is suitable for real-time detection of on-chip integrated devices.

[0176] The group refractive index measuring device provided by the present invention is described below. The group refractive index measuring device described below and the group refractive index measuring method described above can be referred to each other.

[0177] Figure 4 The schematic diagram of the structure of the group refractive index measuring device provided by the present invention is as follows: Figure 4 As shown, the group refractive index measuring device comprises:

[0178] The information acquisition module 410 is used to acquire the position information of the sliding component in the current imaging round, and determine the delay time of the current imaging round based on the position information;

[0179] An imaging acquisition module 420, configured to acquire overlapping images acquired by the first imaging device in the current imaging round;

[0180] The component control module 430 is used to control the movement of the sliding component to move the sliding component to the position of the next imaging round when the current imaging round is not the last imaging round, and use the next imaging round as the current imaging round to obtain a plurality of overlapping imagings with different delay times;

[0181] An information determination module 440, configured to determine the interference fringe intensity distribution information based on the overlapping imaging of the plurality of different delay times;

[0182] The group refractive index determination module 450 is used to determine the group velocity based on the interference fringe intensity distribution information, the delay time of the overlapping imaging of the multiple different delay times and the length of the nanowire sample, and determine the group refractive index of the nanowire sample based on the group velocity.

[0183] In the group refractive index measuring device provided by the embodiment of the present invention, a femtosecond laser light source is optically connected to a microscope objective lens so that the microscope objective lens focuses the excitation light of the femtosecond laser light source on the nanowire sample on the sample stage, that is, the excitation light is focused to the surface of the nanowire sample through the microscope objective lens to serve as pump light to excite the nanowire sample, thereby causing the nanowire sample to generate lasing and radiate coherent outgoing light; and a first beam splitter is optically connected to the microscope objective lens so as to divide the outgoing light collected by the microscope objective lens into a first beam of light and a second beam of light, and a second reflector for reflecting the second beam of light is disposed on a sliding component so that the second reflector can move in a direction away from or close to the first beam splitter, thereby realizing the control of the optical path difference between the first beam of light and the second beam of light, that is, the position information of the sliding component can be obtained in the current imaging round, and the delay time of the current imaging round can be determined based on the position information, thereby obtaining The first imaging device obtains overlapping images in the current imaging round. When the current imaging round is not the last imaging round, the sliding component is controlled to move to move the sliding component to the position of the next imaging round, and the next imaging round is used as the current imaging round to obtain overlapping images with multiple different delay times. Since the emitted light is a coherent laser, the interference fringe intensity distribution information can be determined based on the overlapping imaging with multiple different delay times, so as to detect the change of the light pulse signal on the time scale, that is, to achieve signal resolution on the time scale, and meet the detection requirements of the light pulse generation and transmission process, that is, the group velocity can be determined based on the interference fringe intensity distribution information, the delay time of the overlapping imaging with multiple different delay times and the length of the nanowire sample, and the group refractive index of the nanowire sample can be determined based on the group velocity, and finally the group refractive index measurement of the nanowire sample can be achieved.

[0184] Based on any of the above embodiments, when the nanowire imaging device includes a filter, a spectrometer and a foldable mirror, the group refractive index measurement device further includes:

[0185] A foldable mirror control module, used to control the foldable mirror so that the filter is optically connected to the spectrometer;

[0186] A wavelength adjustment module, used for adjusting the passing wavelength of the filter based on the wavelength information detected by the spectrometer;

[0187] The foldable mirror control module is used to control the foldable mirror so that the filter is optically connected to the first beam splitter.

[0188] Based on any of the above embodiments, when the nanowire imaging device includes a second imaging device, the group refractive index measurement device further includes:

[0189] A sample acquisition module, used to acquire the sample image obtained by the second imaging device;

[0190] A mode determination module, used for determining a movement mode based on the sample imaging;

[0191] The sample stage control module is used to control the movement of the sample stage based on the movement mode.

[0192] Figure 5 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 5 As shown, the electronic device may include: a processor (processor) 510, a communication interface (Communications Interface) 520, a memory (memory) 530 and a communication bus 540, wherein the processor 510, the communication interface 520, and the memory 530 communicate with each other through the communication bus 540. The processor 510 can call the logic instructions in the memory 530 to execute the group refractive index measurement method, which includes: in the current imaging round, obtaining the position information of the sliding component, and determining the delay time of the current imaging round based on the position information; obtaining the overlapping imaging obtained by the first imaging device in the current imaging round; when the current imaging round is not the last imaging round, controlling the movement of the sliding component to move the sliding component to the position of the next imaging round, and taking the next imaging round as the current imaging round to obtain multiple overlapping imaging with different delay times; based on the overlapping imaging with different delay times, determining the interference fringe intensity distribution information; based on the interference fringe intensity distribution information, the delay time of the overlapping imaging with different delay times and the length of the nanowire sample, determining the group velocity, and determining the group refractive index of the nanowire sample based on the group velocity.

[0193] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0194] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the group refractive index measurement method provided by the above methods, which includes: in the current imaging round, obtaining the position information of the sliding component, and determining the delay time of the current imaging round based on the position information; obtaining the overlapping imaging obtained by the first imaging device in the current imaging round; when the current imaging round is not the last imaging round, controlling the sliding component to move to the position of the next imaging round, and taking the next imaging round as the current imaging round to obtain multiple overlapping imaging with different delay times; based on the multiple overlapping imaging with different delay times, determining the interference fringe intensity distribution information; based on the interference fringe intensity distribution information, the delay time of the overlapping imaging with the multiple different delay times and the length of the nanowire sample, determining the group velocity, and determining the group refractive index of the nanowire sample based on the group velocity.

[0195] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the group refractive index measurement method provided by the above-mentioned methods, the method comprising: obtaining position information of the sliding component in a current imaging round, and determining the delay time of the current imaging round based on the position information; obtaining overlapping imaging obtained by the first imaging device in the current imaging round; if the current imaging round is not the last imaging round, controlling the movement of the sliding component to move the sliding component to the position of the next imaging round, and taking the next imaging round as the current imaging round to obtain overlapping imaging with multiple different delay times; determining interference fringe intensity distribution information based on the overlapping imaging with the multiple different delay times; determining the group velocity based on the interference fringe intensity distribution information, the delay time of the overlapping imaging with the multiple different delay times and the length of the nanowire sample, and determining the group refractive index of the nanowire sample based on the group velocity.

[0196] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0197] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0198] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A group refractive index measurement device implemented using a nanowire imaging device, characterized in that: The nanowire imaging device comprises: a sample stage, a femtosecond laser light source, a microscope objective, an interferometer and a first imaging device, wherein the interferometer comprises a first beam splitter, a first reflector, a sliding assembly and a second reflector; The sample stage is used to place the nanowire sample to be measured; The femtosecond laser light source is optically connected to the microscope objective lens, the microscope objective lens is used to focus the excitation light of the femtosecond laser light source on the nanowire sample, and the microscope objective lens is also used to collect the outgoing light of the nanowire sample, the outgoing light is the coherent light emitted after the nanowire sample is lased by the excitation light; The first beam splitter is optically connected to the microscope objective lens, and the first beam splitter is used to split the emitted light into a first beam of light and a second beam of light; The first reflector is optically connected to the first beam splitter, and the first reflector is used to reflect the first beam of light to the first beam splitter; The second reflector is optically connected to the first beam splitter, the second reflector is used to reflect the second light beam to the first beam splitter, the second reflector is arranged on the sliding assembly, and the sliding assembly is used to move the second reflector in a direction away from or close to the first beam splitter; The first imaging device is optically connected to the first beam splitter so that the reflected first beam of light is transmitted to the first imaging device, and the reflected second beam of light is transmitted to the first imaging device, so that the first imaging device obtains overlapping images of the nanowire sample; The nanowire imaging device also includes: a filter, a spectrometer, a foldable mirror and a controller; The first beam splitter is optically connected to the microscope objective lens via the optical filter; The microscope objective is also used to collect reflected light reflected by the nanowire sample, and the filter is used to block the reflected light and transmit the emitted light; The controller is used to control the foldable mirror so that the filter is optically connected to the first beam splitter, or the filter is optically connected to the spectrometer; When the optical filter is optically connected to the spectrometer, the spectrometer is used to detect wavelength information of signal light, and the signal light is light filtered by the optical filter; The controller is used to adjust the passing wavelength of the filter based on the wavelength information; The second reflector is a hollow mirror, comprising a first mirror and a second mirror, wherein the angle between the first mirror and the second mirror is 90 degrees; The first mirror is used to reflect the second light beam to the second mirror, and the second mirror is used to reflect the second light beam reflected by the first mirror to the first beam splitter; The group refractive index measuring device comprises: An information acquisition module, used to acquire position information of the sliding component in a current imaging round, and determine a delay time of the current imaging round based on the position information; An imaging acquisition module, used for acquiring overlapping images acquired by the first imaging device in the current imaging round; A component control module, used for controlling the movement of the sliding component to move the sliding component to a position of a next imaging round when the current imaging round is not the last imaging round, and taking the next imaging round as the current imaging round to obtain a plurality of overlapping imagings with different delay times; An information determination module, used to determine the interference fringe intensity distribution information based on the overlapping imaging of the plurality of different delay times; The group refractive index determination module is used to determine the group velocity based on the interference fringe intensity distribution information, the delay time of the overlapping imaging of the multiple different delay times and the length of the nanowire sample, and determine the group refractive index of the nanowire sample based on the group velocity.

2. The group refractive index measuring device according to claim 1, characterized in that: The interferometer further comprises: a telephoto lens; The first imaging device is optically connected to the first beam splitter through the telephoto lens; The telephoto lens is used to converge the reflected first light beam and the reflected second light beam onto the first imaging device.

3. The group refractive index measuring device according to claim 1, characterized in that: The nanowire imaging device further comprises: a second beam splitter; The femtosecond laser light source is optically connected to the microscope objective lens through the second beam splitter, so that the excitation light is transmitted to the microscope objective lens; The first beam splitter is optically connected to the microscope objective lens through the second beam splitter, so that the output light is transmitted to the first beam splitter.

4. The group refractive index measuring device according to claim 1, characterized in that: The nanowire imaging device further comprises: an illumination light source and a third beam splitter; The illumination light source is optically connected to the microscope objective lens through the third beam splitter, so that the illumination light of the illumination light source is transmitted to the microscope objective lens, and the microscope objective lens is also used to focus the illumination light on the nanowire sample; The first beam splitter is optically connected to the microscope objective lens through the third beam splitter, so that the output light is transmitted to the first beam splitter.

5. The group refractive index measuring device according to claim 1, characterized in that: The nanowire imaging device further comprises: a second imaging device and a controller; The second imaging device is optically connected to the microscope objective lens so that the emitted light is transmitted to the second imaging device, so that the second imaging device can obtain sample imaging of the nanowire sample; The sample stage is a movable stage capable of three-dimensional displacement, and the controller is used to control the movement of the sample stage based on the sample imaging so as to perform imaging and focusing on the nanowire sample.

6. A method for measuring group refractive index using the nanowire imaging device according to any one of claims 1 to 5, characterized in that: include: In a current imaging round, acquiring position information of the sliding component, and determining a delay time of the current imaging round based on the position information; Acquire overlapping images obtained by the first imaging device in the current imaging round; In the case where the current imaging round is not the last imaging round, controlling the sliding component to move to a position of a next imaging round, and using the next imaging round as the current imaging round to obtain a plurality of overlapping imagings with different delay times; Determining interference fringe intensity distribution information based on the overlapping imaging of the plurality of different delay times; The group velocity is determined based on the interference fringe intensity distribution information, the delay time of the overlapping images of the multiple different delay times and the length of the nanowire sample, and the group refractive index of the nanowire sample is determined based on the group velocity.

7. The method for measuring group refractive index according to claim 6, characterized in that: Before acquiring the overlapping images obtained by the first imaging device in the current imaging round, the method further includes: Controlling the foldable mirror to connect the filter to the spectrometer in an optical path; adjusting the passing wavelength of the filter based on the wavelength information detected by the spectrometer; The foldable mirror is controlled to connect the filter with the first beam splitter in an optical path.

8. The method for measuring group refractive index according to claim 6, characterized in that: In the case where the nanowire imaging device includes a second imaging device, before acquiring the overlapping images obtained by the first imaging device in the current imaging round, the method further includes: Acquiring sample imaging obtained by the second imaging device; determining a movement mode based on imaging of the sample; Based on the movement mode, the movement of the sample stage is controlled.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the group refractive index measurement method according to any one of claims 6 to 8 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the group refractive index measurement method according to any one of claims 6 to 8 is implemented.

Images