Optical signal detection system and configuration method thereof, and femtosecond laser imaging system

Abstract

The present application relates to an optical signal detection system and its configuration method, and a femtosecond laser imaging system. The detection system includes: an optical signal spatial positioning control device and multiple optical signal detection devices for measuring multimodal signals; the optical signal spatial positioning control device performs spatial positioning adjustment and control on multimodal signals incident from various angles to obtain a first optical signal output to the first main optical path, so that the first optical signal is adjusted to a specific spatial range within a set transmission distance; each optical signal detection device is distributed around the first main optical path at intervals, and a branch optical path is separated from the first optical signal of the first main optical path, and each modal optical signal is collected and measured. This technical solution can ensure the complete collection of photons in each channel of multimodal signals incident at different angles, ensure the strength of the detection signal, and improve the imaging accuracy of multimodal images.

Description

Technical Field

[0001] The present application relates to the field of laser technology, and in particular to an optical signal detection system and a configuration method thereof, and a femtosecond laser imaging system. Background Art

[0002] In the femtosecond laser imaging system, the femtosecond pulse laser is focused onto the sample through the galvanometer M and the objective lens W to generate fluorescence and harmonic signals. These optical signals contain optical signals of multiple modes (i.e., multimodal signals). In order to detect the nonlinear modal parameters of the optical signals of each mode, a corresponding detection system needs to be designed for detection; refer to Figure 1 As shown, Figure 1 The figure is a schematic diagram of an example multimodal signal detection system. The multimodal signal detection system corresponds to the dotted box part. In the multimodal signal generated by the optical element group where the galvanometer M is located, the multimodal signal returns along the original path. When it is transmitted to the main dichroic mirror (D1), it enters the main optical path after being reflected by it. In the main optical path, multiple dichroic mirrors (D2) with the same number of nonlinear modes required by the imaging system are designed to form multiple branch optical paths. Each nonlinear modal parameter of the multimodal signal in different wavelength ranges is extracted respectively, and then enters the photomultiplier tube (PMT) at the end of the branch optical path for measurement. As shown in the figure, five branch optical paths are designed, and each branch optical path is detected by a corresponding photomultiplier tube.

[0003] In order to clearly reflect the complete information contained in the multimodal system, the femtosecond laser imaging system needs to detect as many photons contained in the fluorescence and harmonic signals as possible. However, in the process of the various types of fluorescence and harmonic signals to be detected moving along the main axis of the branch light path, due to the design influence of the spatial position of the galvanometer, objective lens, main dichroic mirror and photomultiplier tube, the multimodal light signal incident angles generated at different positions in the sample are different. The spatial position of the spot of the actual imaging signal in the main light path fluctuates. The spot in the main light path will change with the propagation distance. The angle of the light path caused by the movement of the galvanometer M changes. The size of the spot close to the central axis obviously changes with the position of the optical axis. Due to the limitation of the spatial position, when a dichroic mirror of a certain size and specification is used at different positions in the first main light path branch, the cross-section of the spot at some positions of the main light path is large, and the dichroic mirror cannot send all the corresponding photons in the main light path into the photomultiplier tube for collection, resulting in the loss of some optical modal signals, affecting the signal intensity and reducing the imaging accuracy of the multimodal image. Summary of the invention

[0004] Based on this, it is necessary to provide an optical signal detection system to address at least one of the above technical issues, ensure the completeness of optical modal signal detection, and improve the imaging accuracy of multimodal images.

[0005] An optical signal detection system, an optical signal spatial positioning control device, and a plurality of optical signal detection devices for measuring multimodal signals; wherein the optical signal spatial positioning control device has an optical element with specific optical parameters built in, and the optical signal detection device has an optical element and an optical signal measurement device built in;

[0006] The optical signal spatial positioning control device performs spatial positioning adjustment control on the multimodal signals incident from various angles to obtain a first optical signal which is output to the first main optical path, so that the first optical signal is adjusted to a specific spatial range within a transmission distance set on the first main optical path;

[0007] The optical signal detection devices are distributed around the first main optical path at intervals, and separate one optical signal from the first optical signal of the first main optical path to form an independent branch optical path, and collect and measure each modal optical signal through the branch optical path.

[0008] In one embodiment, the optical signal detection device comprises: a first dichroic mirror arranged on a first main optical path, and a small convex lens and a photomultiplier tube arranged on a branch optical path; wherein the first dichroic mirror is arranged at a set distance position from the optical signal spatial positioning control device;

[0009] The first dichroic mirror separates a light signal from the first light signal of the first main light path to form a branch light path, and the branch light path passes through a small convex lens and enters the photomultiplier tube for measurement.

[0010] In one embodiment, the optical signal spatial positioning control device includes a main convex lens with set parameters and an optical path guiding device;

[0011] The main convex lens performs spatial positioning adjustment on the multi-modal signals incident at various angles to control the output of the first light signal; the light path guiding device guides the first light signal into the first main light path.

[0012] In one embodiment, the light path guiding device comprises a pair of reflectors; the reflector pair comprises a first reflector and a second reflector arranged opposite to each other, the first reflector being arranged at a set distance from the light emitting end of the main convex lens;

[0013] The first optical signal enters the reflection surface of the first reflection mirror to be reflected, and is reflected by the reflection surface of the second reflection mirror and then input into the first main optical path.

[0014] In one embodiment, the light path guiding device comprises: a second dichroic mirror and a third reflector; the second dichroic mirror is arranged at a set distance from the light emitting end of the main convex lens;

[0015] The main convex lens focuses the incident multi-modal signal to output the first optical signal; the first optical signal is reflected to the third reflector by the second dichroic mirror, and enters the first main optical path after being reflected by the third reflector;

[0016] The first optical signal is separated by a second dichroic mirror into a second optical signal which is directly input into the second main optical path;

[0017] There are several optical signal detection devices distributed around the second main optical path, which are used to separate optical signals from the second optical signal of the second main optical path to form independent branch optical paths so as to collect and measure each modal optical signal.

[0018] In one embodiment, the optical signal detection devices are arranged at intervals on both sides of the first main optical path and / or the second main optical path;

[0019] Alternatively, the optical signal detection devices are arranged in a spaced and distributed manner in a three-dimensional space around the first main optical path and / or the second main optical path.

[0020] A configuration method of an optical signal detection system, applied to the optical signal detection system, is characterized by comprising:

[0021] Establishing an optical path model according to the incident multi-modal signal;

[0022] Calculate the optical parameters of the optical elements in the optical signal spatial positioning control device when the light spot containing the multimodal optical signal is adjusted to a specified spatial range based on the optical path model;

[0023] Calculate the projection intercept value of each optical signal detection device distributed in the main axis direction of the branch light path;

[0024] The parameter specifications and position parameters of the built-in optical elements are established according to the signal modes and projection intercept values ​​corresponding to the measurements of the various optical signal detection devices.

[0025] In one embodiment, the optical parameters of the optical elements in the optical signal spatial positioning control device are calculated based on the optical path model when the light spot is adjusted to a specified spatial range, including:

[0026] Determining the distance and the range of the incident angle between the incident multimodal signal and the main convex lens based on the optical path model;

[0027] Determining a designated spatial range to which the light spot is adjusted;

[0028] The optical parameters of the optical elements in the optical signal spatial positioning control device are calculated according to the distance, the incident angle range and the specified spatial range.

[0029] In one embodiment, the parameter specifications and position parameters of the built-in optical elements are established according to the signal modes and projection intercept values ​​correspondingly measured by each optical signal detection device, including:

[0030] Obtaining the working parameters of the photomultiplier tubes used by each optical signal detection device;

[0031] Acquire a first distance between a small convex lens of each optical signal detection device and the first main optical path and a second distance between each small convex lens and the photomultiplier tube;

[0032] The parameter specifications of the first dichroic mirror and the small convex lens are determined according to the projection intercept value, the first distance, the second distance and the working parameters of the photomultiplier tube.

[0033] A femtosecond laser imaging system comprises: the optical signal detection system described above, and / or uses the configuration method of the optical signal detection system described above to perform optical signal detection.

[0034] The above-mentioned optical signal detection system and its configuration method, and femtosecond laser imaging system, use an optical signal spatial positioning control device with an optical element with specific optical parameters built in to perform spatial positioning adjustment and control on multimodal signals incident from various angles to obtain a first optical signal output to the first main optical path. When the first optical signal is transmitted on the first main optical path, the position of the light spot formed by various multimodal signals within the set transmission distance is adjusted to a specific spatial range; then, multiple optical signal detection devices spaced around the first main optical path are used to separate multiple independent branch optical paths from the first optical signal, and then each modal optical signal is collected and measured. This technical solution can ensure that the photons of each channel of the multimodal signal incident at different angles are completely collected in a limited spatial range, avoid the loss of optical modal signals, ensure the strength of the detection signal, and improve the imaging accuracy of the multimodal image. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic diagram of an exemplary multimodal signal detection system;

[0036] Figure 2 is a schematic diagram of the structure of an optical signal detection system according to an embodiment;

[0037] Figure 3 is a side view of an exemplary first light signal spot;

[0038] Figure 4 is a front view of an example first light signal spot;

[0039] Figure 5 is a schematic structural diagram of an optical signal detection device according to an embodiment;

[0040] Figure 6 is a schematic diagram of an exemplary optical signal detection device distribution;

[0041] Figure 7 is a schematic diagram of an exemplary layout of an optical signal detection device;

[0042] Figure 8 is a schematic diagram of the structure of an exemplary optical signal spatial positioning control device;

[0043] Fig. 9 is a schematic structural diagram of an optical signal spatial positioning control device according to another embodiment;

[0044] Fig.10 is a flow chart of a configuration method of an optical signal detection system according to an embodiment;

[0045] Fig.11 This is a schematic diagram of the structure of an example femtosecond laser imaging system. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0047] The technical solution of the present application is to accurately and quantitatively measure the generated fluorescence and harmonic signals during the imaging process of the femtosecond laser imaging system, thereby improving the imaging accuracy of multimodal images. Figure 2 As shown, Figure 2 It is a schematic diagram of the structure of an optical signal detection system of an embodiment, the system includes: an optical signal spatial positioning control device 01 and multiple optical signal detection devices 02 for measuring multimodal signals, each optical signal detection device 02 is distributed on the first main optical path 04. Among them, the optical signal spatial positioning control device 01 has an optical element with specific optical parameters built in, and the optical signal detection device 02 has an optical element and an optical signal measuring device built in. The optical signal spatial positioning control device 01 performs spatial positioning adjustment and control on the multimodal signals incident at various angles generated on the sample, and obtains a first optical signal output to the first main optical path 04. Based on the action of the optical element with specific optical parameters of the optical signal spatial positioning control device 01, the first optical signal is output to the first main optical path 04 for transmission within a set transmission distance, and the position distribution of the light spots of various multimodal signals included is adjusted to a specific spatial range.

[0048] refer to Figure 3 , Figure 3 is a side view of an example of a first light signal spot, Figure 3 It is a side view. After the multimodal signals incident from different directions generated from the sample are adjusted and controlled by the optical signal spatial positioning control device 01, a light spot within a specific spatial range R is formed within the transmission distance d set in the first main optical path 04. The solid line light and the dotted line light in the figure respectively represent the light states at the upper and lower edge positions of the optical signal spatial positioning control device 01. With the central axis of the first main optical path 04 as a reference, some incident light beams form a focusing effect, while some incident light beams are close to a divergent effect; reference Figure 4 , Figure 4 is a front view of an example of a first light signal spot, Figure 4 It is a view along the transmission direction of the optical path, in which light ray I and light ray II respectively represent the upper and lower edge positions of the optical signal spatial positioning control device 01; similarly, the situations on the left and right sides are similar, thereby forming a light spot within a specific spatial range within the transmission distance set by the first main optical path 04 after all multimodal signals are incident from the optical signal spatial positioning control device 01.

[0049] The optical signal detection devices 02 are distributed at intervals within a certain spatial distance range of the first main optical path 04, and can be distributed on both sides of the first main optical path 04 or in the surrounding three-dimensional space. The optical signal detection devices 02 separate one optical signal from the first main optical path 04 to form an independent branch optical path 41. Based on the built-in optical elements and optical signal measurement devices of the optical signal detection device 02, each independent branch optical path 41 collects and measures at least one modal optical signal. Normally, each optical signal detection device 02 detects an optical signal of one modality.

[0050] The above-mentioned optical signal detection system 100, through the detection system architecture of the optical signal spatial positioning control device 01 and multiple optical signal detection devices 02, the optical signal spatial positioning control device 01 pre-spatial positioning adjustment control of the multi-modal signals incident at various angles generated by the sample, so that the first optical signal is within the transmission distance set on the first main optical path 04, and the spot position of various multi-modal optical signals is adjusted to a specific spatial range. In the case of limited space, each optical signal detection device 02 can use optical elements of certain specifications to complete the complete collection and measurement of each modal optical signal within a limited spatial range. Almost all photons of each modal optical signal can enter the optical signal detection device 02, thereby avoiding the signal loss phenomenon in the optical modality application, ensuring that the collection parameters of each channel are complete, and can effectively improve the imaging accuracy of multi-modal image detection.

[0051] In order to make the technical solution of the present application more clear, more embodiments are described below in conjunction with the accompanying drawings.

[0052] In one embodiment, Figure 5 As shown, Figure 5 It is a schematic diagram of the structure of an optical signal detection device of an embodiment. Furthermore, the optical signal detection device 02 may include a first dichroic mirror 21 and a small convex lens 22 and a photomultiplier tube 23 arranged on the branch light path 41; wherein the first dichroic mirror 21 is arranged on the first main light path 04, separates the branch light path 41 from the first main light path 04, and the small convex lens 22 focuses or amplifies the optical signal of the branch light path 41, and then enters the photomultiplier tube 23 for measurement.

[0053] For the position distribution of the optical signal detection device 02, refer to Figure 6 As shown, Figure 6 1 is a schematic diagram of the distribution of an optical signal detection device as an example; the figure takes five optical signal detection devices 02 as an example, which are numbered ① to ⑤; the corresponding numbers of the first dichroic mirrors 21 are 21a, 21b, 21c, 21d and 21e, and the branch light paths 41 separated by each optical signal detection device 02 are numbered 41a, 41b, 41c, 41d and 41e; the corresponding numbers of the photomultiplier tubes 23 are 23a, 23b, 23c, 23d and 23e, and the corresponding numbers of the small convex lenses 22 are 22a, 22b, 22c, 22d and 22e; as shown in the figure, the spacings between the optical signal detection devices 02 on the first main light path 04 are different, wherein after coming out of the second reflector 122, the distances between the first dichroic mirrors 21a, 21b, 21c, 21d and 21e are l1, l2, l3, l4 and l5 respectively.

[0054] In order to further improve the space utilization, each optical signal detection device 02 is arranged in a three-dimensional space around the first main optical path 04 at intervals; Figure 7 As shown, Figure 7 1 is a schematic diagram of an exemplary layout of an optical signal detection device, which is a cross-sectional view along the main optical axis direction, and five optical signal detection devices 02 are distributed in a three-dimensional space.

[0055] The technical solution of the above embodiment can shorten the distance between the first optical signal detection device 02 and the last optical signal detection device 02 to the maximum extent, because the optical signal detection devices 02 are arranged at intervals on both sides of the first main optical path 04 or in a three-dimensional spatial layout. Combined with the adjustment and control function of the optical signal spatial positioning control device 01 on the light spot, the photons of each modal optical signal can be completely extracted within a short distance, thereby improving the collection efficiency of each channel and making the detection result more accurate.

[0056] In one embodiment, reference Figure 8 , Figure 8The figure is a schematic diagram of the structure of an exemplary optical signal spatial positioning control device, wherein the optical signal spatial positioning control device 01 comprises a main convex lens 11 with set parameters and an optical path guiding device 12; wherein the light part is omitted in the figure, and the dotted line in the figure is the central axis of the optical path, the main convex lens 11 performs spatial positioning control on the incident multimodal signal to output a first optical signal, and the optical path guiding device 12 guides the first optical signal to the first main optical path; the optical path guiding device 12 may include a pair of reflectors, specifically including a first reflector 121 and a second reflector 122, wherein the first reflector 121 is disposed at the light emitting end of the main convex lens 11, and the first reflector 121 and the second reflector 122 are arranged opposite to each other, and the incident multimodal signal enters the reflecting surface of the first reflector 121 from the light emitting end of the main convex lens 11 for right-angle reflection, and then enters the reflecting surface of the second reflector 122 for right-angle reflection and then is output in the first main optical path 04.

[0057] Exemplarily, the first reflector 121 and the second reflector 122 are right-angle prism reflectors, the distance between the first reflector 121 and the main convex lens 11 is adjustable, the distance between the first reflector 121 and the second reflector 122 is adjustable, and the main convex lens 11, the first reflector 121 and the second reflector 122 control the spot diameter of the first main light path 04 by adjusting the optical parameters of the main convex lens 11 and the above-mentioned distance.

[0058] like Figure 8 In the figure, it is assumed that the distance between the main convex lens 11 and the objective lens is H1, the incident angle range of the multimodal signal is r, and after the transmission distance L of the reflector 12 is twice reflected, the first light signal is output to the first main light path 04; for the diameter X and the focal length q of the main convex lens 11, the calculation formula can be as follows:

[0059]

[0060]

[0061] Among them, k1 and k2 are set constants, α is the angle of incident light, generally, the distance H1 ranges from 50 to 300 mm, and the incident spot diameter r of the multimodal signal ranges from 5 to 15 mm; the focal length q of the main convex lens is preferably 50 to 300 mm, and the diameter X of the main convex lens is preferably 12 to 80 mm; the spatial range defined by the first light signal is a cylindrical space distributed along the exit optical axis of the main convex lens, and the diameter R is preferably 12 to 80 mm; the incident light angle а is preferably 1 to 4 degrees; the distance between the main convex lens and the first reflector in the center of the reflector is preferably 10 to 50 mm, and the distance between the first and second reflectors is preferably 10 to 50 mm.

[0062] The technical solution of the above-mentioned embodiment designs the main convex lens 11 and the first reflector 121 and the second reflector 122 with specific optical parameters, adjusts the distance between the main convex lens 11 and the first reflector 121, and the distance between the first reflector 121 and the second reflector 122, so that the position distribution of the light spot after passing through the main lens is controlled to be within a specific set range, so that at the appropriate distance position, the possible positions of the first light signal are all within a specific spatial range, thereby ensuring that the photons of the first main light path 04 are detected as completely as possible by the light signal detection device 02.

[0063] In one embodiment, reference Fig. 9 , Fig. 9 It is a structural schematic diagram of the optical signal spatial positioning and control device of another embodiment, the optical path guiding device 12 can also include a second dichroic mirror 123 and a third reflector 124, the second dichroic mirror 123 is arranged at a set distance from the light output end of the main convex lens 11; the main convex lens 11 focuses the incident multi-modal signal to output a first optical signal, the first optical signal is reflected to the third reflector 124 through the second dichroic mirror 123, and enters the first main optical path 04 after being reflected by the third reflector 124; the first optical signal is separated into a second optical signal through the second dichroic mirror 123 and directly input into the second main optical path 05; wherein, a plurality of optical signal detection devices 02 are distributed around the second main optical path 05, which are used to separate optical signals from the second optical signal of the second main optical path 05 to form an independent branch optical path 51 to collect and measure each modal optical signal.

[0064] Exemplarily, for the position distribution of the optical signal detection device 02 of the second main optical path 05, reference can also be made to the position distribution scheme of the embodiment of the first main optical path 04. As in the above embodiment, the second main optical path 05 is separated from the first main optical path 04 by the second dichroic mirror 123, so that a plurality of main optical paths can be formed, and different numbers of photomultiplier tubes can be set in different main optical paths to collect optical signals of specific modes. Thus, a plurality of photomultiplier tubes can be distributed on different main optical paths, so that the space occupation can be reduced, and the optical signal collection can be expanded to a larger number of channels. As shown in the figure, the photomultiplier tubes ①②⑤ in the five channels can be distributed on the first main optical path, and the photomultiplier tubes ③④ can be distributed on the second main optical path, which optimizes the spatial volume as a whole and improves the detection accuracy.

[0065] An embodiment of a method for configuring an optical signal detection system is described below.

[0066] Based on the optical signal detection system 100 provided in the above embodiment, when performing optical signal detection, optical signals with different diameters and parameters have different requirements on the optical devices of the optical signal detection system 100. In order to accurately configure the optical signal detection system 100 and ensure the accuracy of the detection results, the following configuration method of the optical signal detection system provided in this application is

[0067] like Fig.10 As shown, Fig.10 The present invention is a flow chart of a configuration method of an optical signal detection system according to an embodiment, and the method mainly includes the following processes:

[0068] Step S1, establishing an optical path model according to an incident multi-modal signal.

[0069] Specifically, an optical path model of the optical path transmission of the optical signal detection system 100 is established according to the incident multi-modal signal to be measured, and a corresponding physical model and mathematical model are obtained.

[0070] Step S2, calculating the optical parameters of the optical elements in the optical signal spatial positioning control device when the light spot is adjusted to a specified spatial range based on the optical path model.

[0071] As an embodiment, the adjustment process of step S2 may specifically include the following:

[0072] S201, determining the distance between the incident multimodal signal and the main convex lens and the range of the incident angle based on the optical path model.

[0073] Specifically, the distance of the multimodal signal from the main convex lens can be determined according to the light transmission distance from the main convex lens 11 to the objective lens port, and the range of the incident angle can be determined according to the emission angles of various multimodal signals, such as Figure 8 Middle distance H1 and Fig. 9 The incident diameter r of the multimodal signal.

[0074] S202, determining a designated spatial range to which the light spot is adjusted.

[0075] Specifically, in order to complete the detection of various multimodal signals in a limited space, the spatial range of the light spot to be limited can be determined according to design indicator requirements, such as the volume, layout and maximum distance of the optical path of the optical signal detection device.

[0076] S203, calculating optical parameters of optical elements in the optical signal spatial positioning control device according to the distance, the incident angle range and the specified spatial range.

[0077] Based on the above-mentioned parameters such as the distance between the incident multimodal light signal and the main convex lens, the incident angle range and the specified spatial range, the optical parameters of the main convex lens 11 and the distance L between the first reflector 121 and the second reflector 122, and the distance H2 of the first reflector 121 relative to the main convex lens 11 can be calculated.

[0078] As an example, for the distances H2 and L, the calculation formulas can be expressed as follows:

[0079] H2=αr 2 H1+βr

[0080] L=γ(H1+δH2)+εr 2

[0081] Wherein, α, β, γ, δ, ε are set constants. For example, H1 = 125 mm, r = 10.3 mm. The specific calculation method can be as follows:

[0082] H2=0.51r 2 H1+1.2r

[0083] L=2.3(H1+0.7H2)+9.0r 2

[0084] The technical solution of the above embodiment can calculate the distance H2 and the L value when the light spot is adjusted to within the specified spatial range.

[0085] Step S3, calculating the projection intercept value of each optical signal detection device distributed in the main axis direction of the branch light path.

[0086] Specifically, for each photomultiplier tube 23, the projection intercept value of the branch light path 41 in the main axis direction is calculated, such as the projection intercept l i , i=1,2,3,4,5; such as Figure 5 As shown, the corresponding values ​​are, on the first main optical path 04, the distance l1 between the first dichroic mirror 21a and the second reflector 122, the distance l2 between the first dichroic mirror 21b and the first dichroic mirror 21a, the distance l3 between the first dichroic mirror 21c and the first dichroic mirror 21b, the distance l4 between the first dichroic mirror 21d and the first dichroic mirror 21c, and the distance l5 between the first dichroic mirror 21e and the first dichroic mirror 21d.

[0087] As an example, for the distance l i , its calculation formula can be expressed as follows:

[0088] l i =ζL+ηr 2 +θr

[0089] Wherein, ζ, η, θ are set constants, and i represents the number of the optical signal detection device; illustratively, based on the determined H1, r and L, the specific calculation method can be as follows:

[0090] l1=0.3L+7.5r 2 +10r

[0091] l2=0.17L+3.3r 2 +10r

[0092] l3=0.17L+3.3r 2 +10r

[0093] l4=0.15L+3.1r 2 +7r

[0094] l5=0.15L+3.0r 2 +7r

[0095] The technical solution of the above embodiment can calculate the projection intercept l of the branch light path in the main axis direction when determining the position of each first dichroic mirror 21 on the first main light path 04. i .

[0096] Step S4, establishing parameter specifications and position parameters of the built-in optical elements according to the signal modes and projection intercept values ​​correspondingly measured by each optical signal detection device.

[0097] Specifically, according to the signal mode measured corresponding to the photomultiplier tube 23 and combined with the projection intercept value of the branch light path 41, the parameter specifications of the small convex lens 22 required for each branch light path 41 are determined, such as the first distance h1 between each small convex lens 22 and the first main light path 04 and the second distance h2 between each small convex lens 22 and the photomultiplier tube 23.

[0098] As an example, the process of step S4 may include the following:

[0099] S401, obtaining the working parameters of the photomultiplier tubes used by each optical signal detection device; for example, the photosensitive surface size, shape, collection cone and entrance design lamp parameters of the photomultiplier tubes.

[0100] S402, obtaining a first distance between a small convex lens of each optical signal detection device and the first main optical path and a second distance between each small convex lens and the photomultiplier tube.

[0101] Specifically, the focal length and diameter of the small convex lens to be used and the installation position of the photomultiplier tube are obtained, and the first distance corresponding to the first dichroic mirror and the small convex lens and the second distance between the photomultiplier tube and the small convex lens are determined.

[0102] S403, determining parameter specifications of the first dichroic mirror and the small convex lens according to the projection intercept value, the first distance, the second distance, and the working parameters of the photomultiplier tube.

[0103] Specifically, the parameter specifications of the small convex lens 22, such as the focal length and diameter of the small convex lens, can be solved according to the projection intercept value, the first distance, the second distance and the working parameters of the photomultiplier tube.

[0104] refer to Figures 4 to 7 As shown, the first distance h1 is the distance between the small convex lens 22 and the first dichroic mirror 21, and the second distance h2 is the distance between the small convex lens 22 and the photomultiplier tube 23. For different optical signal detection devices 02, since the optimal value of the first distance h1 may be the same or different, the optimal value of the second distance h2 may also be the same or different, so the optimal value can be obtained by optimization calculation. Constraints are set according to the parameters of the photomultiplier tube 23 detecting each modal optical signal. Solve the objective function under the constraints to obtain the optimal parameter specifications of the small convex lens 22.

[0105] As an example, for the distances h1 and h2, the calculation formulas can be expressed as follows:

[0106] h 1i =κl i +λr 2

[0107] h 2i =μl i +r

[0108] Wherein, κ, λ, μ are set constants, and i represents the number of the optical signal detection device; for example, based on the determined l i and r, the specific calculation method can be as follows:

[0109] h 1i =7.0l i +2.0r 2 i=1,2,3,4,5

[0110] h 2i =3.0l i +ri=1,2,3,4,5

[0111] The technical solution of the above embodiment can accurately calculate the optimal parameter specifications of the small convex lens according to the layout positions of the selected small convex lens and the photomultiplier tube. Generally, l1 to l5 are preferably the same or different values ​​of 10-50mm; one or more of the small convex lenses in l1 to l5 are made of ultraviolet molten glass so as to fully receive all photons in the corresponding wavelength range of at least one mode in the optical signal; h11 to h 15 Preferably the same or different values ​​of 10-200 mm; h 21 to h 25 Preferably, they are the same or different values ​​of 10-200 mm; the focal lengths of the various small convex lenses are preferably the same or different values ​​of 10-200 mm.

[0112] The technical solution of the above-mentioned embodiment is to conduct simulation tests through the established optical path model, change the parameters of the main convex lens 11 to regulate the spatial positioning of the light signal on the optical axis, realize accurate simulation, accurate calculation, and accurate determination of the optical parameters and positions of the small convex lenses 22, so as to obtain the optimal layout positions of each small convex lens 22 and the photomultiplier tube 23 and the parameter specifications of the optical elements used. Based on the optimal layout position, it can be ensured that the acquisition parameters of each channel are complete. Through the feedback of subsequent detection parameters, it can be determined whether the detected parameters are complete, so that the quantitative detection of the photomultiplier tube 23 is more accurate.

[0113] An embodiment of a femtosecond laser imaging system is described below.

[0114] The femtosecond laser imaging system provided in this embodiment includes: the optical signal detection system 100 of the above embodiment, and applies the configuration method of the optical signal detection system 100 of the above embodiment to perform optical signal detection.

[0115] Exemplary, reference Fig.10 As shown, Fig.10 The figure is a schematic diagram of the structure of an exemplary femtosecond laser imaging system, in which a laser light source generates a femtosecond laser pulse, which is derived through a corresponding optical device and irradiated on a sample on a sample platform. The femtosecond laser pulse interacts with the molecules of the sample to generate a multimodal signal with non-overlapping or partially overlapping bands. In general, the multimodal signal includes harmonics and fluorescence signals of specific molecules. Harmonics can be divided into second harmonics, third harmonics, and even fourth harmonics or above. In order to detect these multimodal optical signals, an optical signal detection system 100 including multiple independent channels is provided. As shown in the figure, channels 1-5 can independently collect optical signals of 5 non-overlapping bands, and each channel corresponds to the spectral signal of a specific band in the multimodal signal, and is finally sent to a spectral signal processing device for processing and use. Due to the use of the optical signal detection system 100 and its configuration method of the embodiment of the present application, the collection efficiency of each channel can be ensured, and the collection parameters of each channel can be guaranteed to be complete based on the optimal layout position of each small convex lens and photomultiplier tube, so that the quantitative detection of the photomultiplier tube is more accurate.

[0116] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. An optical signal detection system, characterized in that: include: An optical signal spatial positioning control device and a plurality of optical signal detection devices for measuring multimodal signals; wherein the optical signal spatial positioning control device has an optical element with specific optical parameters built in, and the optical signal detection device has an optical element and an optical signal measuring device built in; the optical signal spatial positioning control device includes a main convex lens with set parameters and an optical path guiding device; The optical signal spatial positioning control device performs spatial positioning adjustment and control on the multimodal signals incident from various angles to obtain a first optical signal, which is output to the first main optical path, wherein the main convex lens performs spatial positioning adjustment and control on the multimodal signals incident from various angles to output the first optical signal; the optical path guiding device guides the first optical signal to the first main optical path, so that the first optical signal is adjusted to a specific spatial range within the transmission distance set on the first main optical path, forming a light spot within the specific spatial range, and the position distribution of the light spots of various multimodal signals contained therein is adjusted to a specific spatial range; Each of the optical signal detection devices is spaced and distributed around the first main optical path within a certain spatial distance range, and separates one optical signal from the first optical signal of the first main optical path to form an independent branch optical path, and collects and measures each modal optical signal through the branch optical path; The optical signal detection device comprises: a first dichroic mirror arranged on a first main optical path, and a small convex lens and a photomultiplier tube arranged on a branch optical path; wherein the first dichroic mirror is arranged at a set distance position from the optical signal spatial positioning control device; the parameter specifications of the small convex lens of each optical signal detection device are calculated according to the layout positions of the selected small convex lens and the photomultiplier tube; The first dichroic mirror separates a light signal from the first light signal of the first main light path to form a branch light path, and the branch light path passes through a small convex lens and enters the photomultiplier tube for measurement.

2. The optical signal detection system according to claim 1, characterized in that: The optical path guiding device comprises a pair of reflectors; the reflector pair comprises a first reflector and a second reflector arranged opposite to each other, the first reflector being arranged at a set distance from the light emitting end of the main convex lens; The first optical signal enters the reflection surface of the first reflection mirror to be reflected, and is reflected by the reflection surface of the second reflection mirror and then input into the first main optical path.

3. The optical signal detection system according to claim 1, characterized in that: The light path guiding device comprises: a second dichroic mirror and a third reflecting mirror; the second dichroic mirror is arranged at a set distance from the light emitting end of the main convex lens; The main convex lens focuses the incident multi-modal signal to output the first optical signal; the first optical signal is reflected to the third reflector by the second dichroic mirror, and enters the first main optical path after being reflected by the third reflector; The first optical signal is separated by a second dichroic mirror into a second optical signal which is directly input into the second main optical path; There are several optical signal detection devices distributed around the second main optical path, which are used to separate optical signals from the second optical signal of the second main optical path to form independent branch optical paths so as to collect and measure each modal optical signal.

4. The optical signal detection system according to claim 2 or 3, characterized in that: The optical signal detection devices are arranged at intervals and distributed on both sides of the first main optical path and / or the second main optical path; Alternatively, the optical signal detection devices are arranged in a spaced and distributed manner in a three-dimensional space around the first main optical path and / or the second main optical path.

5. A configuration method for an optical signal detection system, applied to the optical signal detection system according to any one of claims 1 to 4, characterized in that: include: Establishing an optical path model according to the incident multi-modal signal; Calculate the optical parameters of the optical elements in the optical signal spatial positioning control device when the light spot containing the multimodal optical signal is adjusted to a specified spatial range based on the optical path model; Calculate the projection intercept value of each optical signal detection device distributed in the main axis direction of the branch light path; The parameter specifications and position parameters of the built-in optical elements are established according to the signal modes and projection intercept values ​​corresponding to the measurements of the various optical signal detection devices.

6. The configuration method of the optical signal detection system according to claim 5, characterized in that: The optical parameters of the optical elements in the optical signal spatial positioning control device are calculated based on the optical path model when the light spot is adjusted to a specified spatial range, including: Determining the distance and the range of the incident angle between the incident multimodal signal and the main convex lens based on the optical path model; Determining a designated spatial range to which the light spot is adjusted; The optical parameters of the optical elements in the optical signal spatial positioning control device are calculated according to the distance, the incident angle range and the specified spatial range.

7. The configuration method of the optical signal detection system according to claim 6, characterized in that: The method of establishing the parameter specifications and position parameters of the built-in optical elements according to the signal modes and projection intercept values ​​corresponding to the measurements of the optical signal detection devices includes: Obtaining the working parameters of the photomultiplier tubes used by each optical signal detection device; Acquire a first distance between a small convex lens of each optical signal detection device and the first main optical path and a second distance between each small convex lens and the photomultiplier tube; The parameter specifications of the first dichroic mirror and the small convex lens are determined according to the projection intercept value, the first distance, the second distance and the working parameters of the photomultiplier tube.

8. A femtosecond laser imaging system, characterized in that: include: The optical signal detection system according to any one of claims 1 to 4, and / or the configuration method of the optical signal detection system according to any one of claims 5 to 7 is used to perform optical signal detection.

Images