Aberration-free laser spot scanning apparatus for optical microscopic imaging

Abstract

An aberration-free laser spot scanning apparatus, comprising a resonant scanner (1), a first concave mirror (2), a second concave mirror (3), an X-axis galvanometer scanning mirror (4), a third concave mirror (5), a fourth concave mirror (6) and a Y-axis galvanometer scanning mirror (7) which are sequentially arranged in the direction of light beam propagation. Compared with existing laser spot scanning apparatuses that generally use a lens as an optical relay element between scanning mirrors, replacing the lens with a concave mirror to complete optical relay between scanning mirrors can avoid spherical aberration in a focusing transmission element, while also reducing the optical power loss generated by light transmission through a glass element, so that the aberration-free laser spot scanning apparatus can be applied to an optical microscopic imaging (e.g., laser confocal and two-photon imaging) system.

Description

Aberration-free laser point scanning device for optical microscopy Technical Field

[0001] The present application relates to the field of multiphoton microscopy technology, and in particular to an aberration-free laser point scanning device for optical microscopy. Background Art

[0002] Optical microscopy techniques (such as confocal imaging and multiphoton imaging) have high resolution and good signal-to-noise ratio, and have become indispensable research tools in life science and medical research. The scanning device composed of a galvanometer scanning mirror and a resonant galvanometer is an essential core component in this type of imaging system. Due to the need to expand the excitation beam and the large scanning angle range of the scanning mirror, an optical relay needs to be added between the scanning mirrors. Existing optical relays mostly use lenses as core components. However, due to the existence of spherical aberration / chromatic aberration, lens-based optical relays will affect the quality of the excitation beam and the point spread function. In addition, the projection element will inevitably cause light loss, thereby reducing the excitation light power.

[0003] Summary of the Invention

[0004] In view of this, it is necessary to provide an aberration-free laser point scanning device for optical microscopy imaging that reduces light loss and improves system efficiency in order to address the technical defects of the prior art.

[0005] To solve the above problems, this application adopts the following technical solutions:

[0006] The present application provides an aberration-free laser point scanning device for optical microscopy imaging, comprising a laser control module (100) and a resonant galvanometer mirror (1), a first concave mirror (2), a second concave mirror (3), an X-axis galvanometer scanning mirror (4), a third concave mirror (5), a fourth concave mirror (6), a Y-axis galvanometer scanning mirror (7), a reflector (8), a first lens (9), a second lens (10), a dichroic mirror (11), an objective lens (12) and a detection module (13) arranged in sequence along the propagation direction of a light beam emitted by the laser control module (100). When the resonant galvanometer mirror (1) is in a stationary state, the X-axis galvanometer scanning mirror (4) and the Y-axis galvanometer scanning mirror (7) are used to perform full-width scanning within the entire field of view; when the X-axis galvanometer scanning mirror (4) completes deflection of a specified angle and is in a stationary state, the resonant galvanometer mirror (1) and the Y-axis galvanometer scanning mirror (7) are combined to perform rapid scanning within a partial field of view, wherein:

[0007] When the X-axis galvanometer scanning mirror (4) and the Y-axis galvanometer scanning mirror (7) are used to perform full-width scanning imaging within the entire field of view, the resonant galvanometer mirror (1) is in a stationary state: the excitation light beam emitted by the laser control module (100) is incident on the surface of the resonant galvanometer mirror (1), and is reflected by the first concave mirror (2) and the second concave mirror (3) in sequence, and then focused on the X-axis galvanometer scanning mirror (4); the excitation light beam reflected by the X-axis galvanometer scanning mirror (4) is reflected by the third concave mirror ( 5) and the fourth concave mirror (6), and then focused on the Y-axis galvanometer scanning mirror (7); the excitation light beam is reflected by the Y-axis galvanometer scanning mirror (7), and then sequentially passes through the reflector (8), the first lens (9), the second lens (10), the dichroic mirror (11) and the objective lens (12) to be focused in the tissue to be measured; the emission light generated by the excitation is collected by the objective lens (12), reflected by the dichroic mirror (11), and finally detected by the detection module (13), completing the scanning imaging task;

[0008] When the resonant galvanometer (1) and the Y-axis galvanometer scanning mirror (7) are used to perform rapid scanning imaging within a partial field of view, the X-axis galvanometer scanning mirror (4) is in a stationary state: the excitation light beam emitted by the laser control module (100) is incident on the surface of the resonant galvanometer (1), and is reflected by the first concave mirror (2) and the second concave mirror (3) in sequence, and then focused on the X-axis galvanometer scanning mirror (4); the excitation light beam reflected by the X-axis galvanometer scanning mirror (4) is reflected by the third concave mirror (3) in sequence, and then focused on the X-axis galvanometer scanning mirror (4); (5) and the fourth concave mirror (6), and then focused on the Y-axis galvanometer scanning mirror (7); the excitation light beam is reflected by the Y-axis galvanometer scanning mirror (7) and then sequentially focused on the tissue to be measured by the reflector (8), the first lens (9), the second lens (10), the dichroic mirror (11) and the objective lens (12); the emission light generated by the excitation is collected by the objective lens (12), reflected by the dichroic mirror (11), and finally detected by the detection module (13), completing the scanning imaging task.

[0009] In some embodiments, the first concave mirror and the second concave mirror are identical and symmetrically arranged to perform optical relay between the resonant galvanometer mirror and the X-axis scanning mirror.

[0010] In some embodiments, the third concave mirror is identical to the fourth concave mirror, and the two are symmetrically arranged to perform optical relay between the X-axis scanning mirror and the Y-axis scanning mirror.

[0011] This application adopts the above technical solution, and its beneficial effects are as follows:

[0012] The aberration-free laser point scanning device provided in this application avoids the spherical aberration / chromatic aberration caused by the lens and reduces the light loss to almost zero. This technology can achieve aberration-free laser point scanning without increasing manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0014] FIG1 is a schematic structural diagram of an aberration-free laser point scanning device for optical microscopy imaging provided in this application. DETAILED DESCRIPTION

[0015] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0016] In the description of this application, it should be understood that the terms "upper", "lower", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0017] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0018] In order to make the purpose, technical solutions and advantages of this application more clear, this application is further described in detail below with reference to the accompanying drawings and embodiments.

[0019] Referring to FIG1 , this embodiment provides an aberration-free laser point scanning device for optical microscopy imaging, comprising a laser control module (100) and a resonant galvanometer mirror (1), a first concave mirror (2), a second concave mirror (3), an X-axis galvanometer scanning mirror (4), a third concave mirror (5), a fourth concave mirror (6), a Y-axis galvanometer scanning mirror (7), a reflector (8), a first lens (9), a second lens (10), a dichroic mirror (11), an objective lens (12), and a detection module (13) arranged in sequence along the propagation direction of the light beam emitted by the laser control module (100). When the resonant galvanometer mirror (1) is in a stationary state, the X-axis galvanometer scanning mirror (4) and the Y-axis galvanometer scanning mirror (7) are used to perform full-width scanning within the entire field of view; when the X-axis galvanometer scanning mirror (4) completes the deflection of a specified angle and is in a stationary state, the resonant galvanometer mirror (1) and the Y-axis galvanometer scanning mirror (7) are combined to perform rapid scanning within a partial field of view, wherein:

[0020] When the X-axis galvanometer scanning mirror (4) and the Y-axis galvanometer scanning mirror (7) are used to perform full-width scanning imaging within the entire field of view, the resonant galvanometer mirror (1) is in a stationary state: the excitation light beam emitted by the laser control module (100) is incident on the surface of the resonant galvanometer mirror (1), and is reflected by the first concave mirror (2) and the second concave mirror (3) in sequence, and then focused on the X-axis galvanometer scanning mirror (4); the excitation light beam reflected by the X-axis galvanometer scanning mirror (4) is reflected by the third concave mirror ( 5) and the fourth concave mirror (6), and then focused on the Y-axis galvanometer scanning mirror (7); the excitation light beam is reflected by the Y-axis galvanometer scanning mirror (7), and then sequentially passes through the reflector (8), the first lens (9), the second lens (10), the dichroic mirror (11) and the objective lens (12) to be focused in the tissue to be measured; the emission light generated by the excitation is collected by the objective lens (12), reflected by the dichroic mirror (11), and finally detected by the detection module (13), completing the scanning imaging task.

[0021] When the resonant galvanometer (1) and the Y-axis galvanometer scanning mirror (7) are used to perform rapid scanning imaging within a partial field of view, the X-axis galvanometer scanning mirror (4) is in a stationary state: the excitation light beam emitted by the laser control module (100) is incident on the surface of the resonant galvanometer (1), and is reflected by the first concave mirror (2) and the second concave mirror (3) in sequence, and then focused on the X-axis galvanometer scanning mirror (4); the excitation light beam reflected by the X-axis galvanometer scanning mirror (4) is reflected by the third concave mirror (3) in sequence, and then focused on the X-axis galvanometer scanning mirror (4); (5) and the fourth concave mirror (6), and then focused on the Y-axis galvanometer scanning mirror (7); the excitation light beam is reflected by the Y-axis galvanometer scanning mirror (7) and then sequentially focused on the tissue to be measured by the reflector (8), the first lens (9), the second lens (10), the dichroic mirror (11) and the objective lens (12); the emission light generated by the excitation is collected by the objective lens (12), reflected by the dichroic mirror (11), and finally detected by the detection module (13), completing the scanning imaging task.

[0022] This application uses two-photon neurocalcitonin imaging of the living mouse brain as an example. The working method is as follows:

[0023] GCaMP is used to label neural cell calcium activity. When the X / Y-axis scanning mirror is used to perform full-width scanning imaging across the entire field of view (with the resonant galvanometer mirror at rest), a 920-nanometer excitation beam is incident on the resonant galvanometer mirror surface and sequentially reflected by the first and second concave mirrors (the first and second concave mirrors form an optical relay), before being focused on the X-axis scanning mirror. The excitation beam, reflected by the X-axis scanning mirror, is sequentially reflected by the third and fourth concave mirrors (the third and fourth concave mirrors form an optical relay), before being focused on the Y-axis scanning mirror. After reflection from the Y-axis scanning mirror, the excitation beam enters the microscopic imaging module (composed of the first lens, the second lens, and the objective lens) and is focused within the tissue being measured. Fluorescence generated by the excitation is collected by the objective lens, reflected by the dichroic mirror, and ultimately detected by the light detection module, completing the imaging task. This imaging task typically requires a continuous cycle to record changes in neural calcium activity.

[0024] However, the imaging speed based on X / Y galvanometer scanning mirror is slow and cannot meet the temporal resolution requirements for detecting neural calcium activity.

[0025] When the resonant galvanometer and the Y-axis scanning mirror are used for rapid scanning imaging within a partial field of view (the X-axis scanning mirror is stationary), a 920-nanometer excitation beam is incident on the surface of the resonant galvanometer and sequentially reflected by the first and second concave mirrors (the first and second concave mirrors form an optical relay), and then focused on the X-axis scanning mirror. The excitation beam reflected by the X-axis scanning mirror is sequentially reflected by the third and fourth concave mirrors (the third and fourth concave mirrors form an optical relay), and then focused on the Y-axis scanning mirror. After being reflected by the Y-axis scanning mirror, the excitation beam enters the microscopic imaging module (composed of the first lens, the second lens, and the objective lens) and is focused within the tissue to be measured. The emitted light (such as fluorescence) generated by the excitation is collected by the objective lens, reflected by the dichroic mirror, and ultimately detected by the light detection module, completing the scanning imaging task. This imaging task generally needs to be performed continuously to record changes in neural calcium activity over time.

[0026] The aberration-free laser point scanning device provided by the embodiments of the present application avoids the spherical and chromatic aberrations caused by lenses and reduces light loss to almost zero. This technology enables aberration-free laser point scanning without increasing manufacturing costs.

[0027] It can be understood that the various technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0028] The above are merely preferred embodiments of the present application and only specifically describe the technical principles of the present application. These descriptions are intended only to explain the principles of the present application and should not be construed in any way as limiting the scope of protection of the present application. Based on the explanations herein, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application, as well as other specific implementations of the present application that can be conceived by those skilled in the art without inventive effort, shall be included within the scope of protection of the present application.

Claims

1. An aberration-free laser point scanning device for optical microscopy imaging, characterized in that: The invention comprises a laser control module (100), and a resonant galvanometer (1), a first concave mirror (2), a second concave mirror (3), an X-axis galvanometer scanning mirror (4), a third concave mirror (5), a fourth concave mirror (6), a Y-axis galvanometer scanning mirror (7), a reflector (8), a first lens (9), a second lens (10), a dichroic mirror (11), an objective lens (12), and a detection module (13) which are sequentially arranged along the propagation direction of a light beam emitted by the laser control module (100); when the resonant galvanometer (1) is in a stationary state, the X-axis galvanometer scanning mirror (4) and the Y-axis galvanometer scanning mirror (7) are used to perform full-width scanning within the entire field of view; when the X-axis galvanometer scanning mirror (4) has completed deflection at a specified angle and is in a stationary state, the resonant galvanometer (1) and the Y-axis galvanometer scanning mirror (7) are combined to perform rapid scanning within a partial field of view, wherein: When the X-axis galvanometer scanning mirror (4) and the Y-axis galvanometer scanning mirror (7) are used to perform full-width scanning imaging within the entire field of view, the resonant galvanometer mirror (1) is in a stationary state: the excitation light beam emitted by the laser control module (100) is incident on the surface of the resonant galvanometer mirror (1), and is reflected by the first concave mirror (2) and the second concave mirror (3) in sequence, and then focused on the X-axis galvanometer scanning mirror (4); the excitation light beam reflected by the X-axis galvanometer scanning mirror (4) is reflected by the third concave mirror (5 ) and the fourth concave mirror (6), and then focused on the Y-axis galvanometer scanning mirror (7); the excitation light beam is reflected by the Y-axis galvanometer scanning mirror (7), and then passes through the reflector (8), the first lens (9), the second lens (10), the dichroic mirror (11) and the objective lens (12) in sequence and is focused on the tissue to be tested; the emission light generated by the excitation is collected by the objective lens (12), and after being reflected by the dichroic mirror (11), it is finally detected by the detection module (13), thereby completing the scanning imaging task; When the resonant galvanometer (1) and the Y-axis galvanometer scanning mirror (7) are used to perform rapid scanning imaging within a partial field of view, the X-axis galvanometer scanning mirror (4) is in a stationary state: the excitation light beam emitted by the laser control module (100) is incident on the surface of the resonant galvanometer (1), and is reflected by the first concave mirror (2) and the second concave mirror (3) in sequence, and then focused on the X-axis galvanometer scanning mirror (4); the excitation light beam reflected by the X-axis galvanometer scanning mirror (4) is sequentially reflected by the third concave mirror (5) and the fourth concave mirror (6), and then focused on the Y-axis galvanometer scanning mirror (7); After being reflected by the Y-axis galvanometer scanning mirror (7), the excitation light beam is sequentially focused into the tissue to be tested through the reflecting mirror (8), the first lens (9), the second lens (10), the dichroic mirror (11) and the objective lens (12); the emission light generated by the excitation is collected by the objective lens (12), reflected by the dichroic mirror (11), and finally detected by the detection module (13), thereby completing the scanning imaging task.

2. The aberration-free laser point scanning device for optical microscopic imaging according to claim 1, characterized in that: The first concave mirror is identical to the second concave mirror, and the two are symmetrically arranged for optical relay between the resonant galvanometer mirror and the X-axis scanning mirror.

3. The aberration-free laser point scanning device for optical microscopic imaging according to claim 1, characterized in that: The third concave mirror is identical to the fourth concave mirror, and the two are symmetrically arranged for optical relay between the X-axis scanning mirror and the Y-axis scanning mirror.

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