Dispersion compensation unit, dispersion compensation method and optical resonant cavity

Abstract

The invention provides a dispersion compensation unit, a dispersion compensation method and an optical resonant cavity. The method comprises the following steps: determining a required dispersion compensation amount according to a laser beam to be compensated; selecting at least one pair of chirp mirrors according to the dispersion compensation amount, and determining the reflection times of the laser beam to be compensated between the at least one pair of chirp mirrors; wherein each pair of chirp mirrors in at least one pair of chirp mirrors comprises two chirp mirrors which are symmetrically arranged; enabling a laser beam to be compensated to enter one of at least one pair of chirp mirrors; and the reflection angles of other chirp mirrors in the at least one pair of chirp mirrors and the reflection angle of a zero-degree total reflection mirror located on the light emitting side of the at least one pair of chirp mirrors are adjusted, so that the reflection times of the laser beam to be compensated between the at least one pair of chirp mirrors reach the determined reflection times, and the laser beam is reflected by the zero-degree total reflection mirror and then returns from the original path. According to the method provided by the invention, the dispersion amount can be adjusted step by step and is easy to adjust, so that the laser beam with higher accuracy is obtained.

Description

Technical Field

[0001] The present invention belongs to the field of ultrafast laser technology, and in particular, relates to a dispersion compensation unit, an optical resonant cavity and a method for performing dispersion compensation on a laser beam. Background Art

[0002] In the field of ultrafast lasers, a pair of chirped mirrors with a fixed dispersion amount (a specific dispersion amount will be generated each time the light passes through the chirped mirror) or multiple pairs of chirped mirrors with a fixed dispersion amount are generally inserted into the optical resonator to compensate for the dispersion amount in the optical resonator. Grating pairs or prism pairs can also be used to achieve the same dispersion control and pulse shaping effects.

[0003] However, in the prior art, in actual applications, there may be a situation where the calculated dispersion amount does not match the actual amount, but the compensated dispersion amount is fixed, which brings great inconvenience to production and experiments.

[0004] The contents of the background technology section are merely the technologies known to the inventors and do not necessarily represent the prior art in the field. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides an automatic dispersion compensation unit with adjustable dispersion amount, comprising:

[0006] At least one pair of first rotating tables, wherein the two first rotating tables of each pair of first rotating tables are symmetrically arranged;

[0007] A pair of second rotating tables, the two second rotating tables are symmetrically arranged;

[0008] At least one pair of first optical adjustment frames, wherein the two first optical adjustment frames of each pair of first optical adjustment frames are respectively mounted on the two first rotating tables;

[0009] A pair of second optical adjustment frames, each of which is mounted on the pair of second rotating platforms;

[0010] at least one pair of chirped mirrors, wherein the two chirped mirrors of each pair of chirped mirrors have the same dispersion amount and are respectively mounted on the two first optical adjustment frames; and

[0011] A pair of zero-degree total reflection mirrors, each zero-degree total reflection mirror is mounted on the pair of second optical adjustment frames;

[0012] The rotation angle of the at least one pair of first rotating tables, the rotation angle of the pair of second rotating tables and the angle of the pair of second optical adjustment frames can be adjusted respectively, so that the number of reflections of the laser beam incident on one of the at least one pair of chirped mirrors between the at least one pair of chirped mirrors can be adjusted, and the laser beam can return from the original path after being reflected by the at least one pair of chirped mirrors and the pair of zero-degree total reflection mirrors.

[0013] In some embodiments of the present application, the dispersion compensation unit further includes a control element for controlling the rotation angle of the at least one pair of first rotating stages, the rotation angle of the pair of second rotating stages, and the angle of the pair of second optical adjustment frames.

[0014] In some embodiments of the present application, the dispersion compensation unit further includes a display for displaying the optical path and / or dispersion amount of the laser beam.

[0015] In some embodiments of the present application, the dispersion compensation unit further includes a display for displaying the rotation angle of the at least one pair of first rotating stages, the rotation angle of the pair of second rotating stages, and the angle of the pair of second optical adjustment frames.

[0016] In some embodiments of the present application, the dispersion of each of the at least one pair of chirped mirrors is -35 fs. 2 or -50fs 2 .

[0017] In some embodiments of the present application, the at least one pair of chirped mirrors is any one of a concave chirped mirror, a convex chirped mirror, and a planar chirped mirror.

[0018] In some embodiments of the present application, the pair of zero-degree total reflection mirrors is any one of a concave zero-degree total reflection mirror, a convex zero-degree total reflection mirror and a flat zero-degree total reflection mirror.

[0019] The present application further provides an optical resonant cavity, comprising any of the above-mentioned dispersion compensation units.

[0020] The present application also provides a method for dispersion compensation of a laser beam, comprising:

[0021] Determining the required dispersion compensation amount according to the laser beam to be compensated;

[0022] According to the dispersion compensation amount, at least one pair of chirped mirrors is selected, and the number of reflections of the laser beam to be compensated between the at least one pair of chirped mirrors is determined; wherein each pair of chirped mirrors in the at least one pair of chirped mirrors includes two chirped mirrors that are symmetrically arranged;

[0023] injecting the laser beam to be compensated into one of the at least one pair of chirped mirrors; and

[0024] Adjust the reflection angles of other chirped mirrors in the at least one pair of chirped mirrors and the reflection angle of the zero-degree total reflection mirror located on the light-emitting side of the at least one pair of chirped mirrors, so that the number of reflections of the laser beam to be compensated between the at least one pair of chirped mirrors reaches the determined number of reflections, and returns from the original path after being reflected by the zero-degree total reflection mirror.

[0025] In some embodiments of the present application, the method further includes:

[0026] confirming an optical path of the compensated laser beam according to a reflection angle of the at least one pair of chirped mirrors; and

[0027] The vibration frequency of the compensated laser beam is confirmed based on the optical path.

[0028] The present application fixes a chirped mirror pair with a fixed dispersion amount on a rotating table, and adjusts the reflection angle of the chirped mirror by rotating the rotating table, thereby adjusting the reflection angle of the laser beam between the chirped mirrors, and then realizing the dispersion amount adjustment step length of an integer multiple of a single chirped mirror. At the same time, a zero-degree total reflection mirror is provided at the light outlet, and the laser beam is returned to the original path by adjusting the angle of the corresponding rotating table and / or adjustment frame. In this way, the dispersion amount can be adjusted in steps, and it is easy to adjust.

[0029] The method provided in the present application can achieve step-by-step adjustment of the dispersion amount, and is easy to adjust, thereby obtaining a laser beam with higher precision.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute improper limitations on the present disclosure.

[0032] Figure 1 The optical path of the laser beam between the chirped mirror and the zero-degree total reflection mirror provided by one embodiment of the present application is shown.

[0033] Figure 2 The optical path of a laser beam between a chirped mirror and a zero-degree total reflection mirror provided by another embodiment of the present application is shown.

[0034] Figure 3 A process flow chart of dispersion compensation for a laser beam provided in one embodiment of the present application is shown. DETAILED DESCRIPTION

[0035] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0036] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and installations of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or installations discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may recognize the application of other processes and / or the use of other materials.

[0037] In the present invention, the terms "first", "second" and other ordinal numbers are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0038] 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, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances. In addition, in the drawings, in order to effectively describe the technical content, the thickness, proportion and size of the components are exaggerated or reduced.

[0039] In addition, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those of ordinary skill in the art to which the present invention belongs. It will also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and the present invention, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0040] As used herein, "about" or "approximately" includes the stated value and means within an acceptable range of deviation from the particular value as determined by one skilled in the art, taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0041] The following is a more detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings and examples, so that the scheme of the present invention and its advantages in various aspects can be better understood. However, the specific embodiments and examples described below are only for the purpose of illustration, rather than for limiting the present invention.

[0042] The present application provides a dispersion compensation unit, which includes at least one pair of first rotating platforms, a pair of second rotating platforms, at least one pair of first optical adjustment frames, a pair of second optical adjustment frames, at least one pair of chirped mirrors and a pair of zero-degree total reflection mirrors.

[0043] Among them, the two first rotating tables of each pair of first rotating tables are symmetrically arranged. The first rotating table is used to carry the first optical adjustment frame, and the two first optical adjustment frames of each pair of first optical adjustment frames are respectively installed on the two first rotating tables, so as to adjust the reflection angle of the chirped mirror to the laser beam, and then adjust the number of reflections of the laser beam between the chirped mirrors. The two chirped mirrors of each pair of chirped mirrors have the same dispersion amount and are respectively installed on the two first optical adjustment frames. That is, the two chirped mirrors in each pair of installed chirped mirrors are also relative. The number of first rotating tables is the same as the number of first optical adjustment frames and chirped mirrors. In the present application, the number of first rotating tables, the number of first optical adjustment frames, and the number of chirped mirrors can be two respectively.

[0044] In the present application, the reflection angle of the chirped mirror to the laser beam can be adjusted by adjusting the angle of the first optical adjustment frame in addition to adjusting the rotation angle of the first rotating stage. However, the aforementioned method of adjusting the reflection angle of the chirped mirror to the laser beam only by adjusting the angle of the first rotating stage is simpler and therefore more preferred.

[0045] The two second rotating tables are symmetrically arranged. The second rotating tables are used to carry the second optical adjustment frames, and the two second optical adjustment frames are respectively mounted on the two second rotating tables, so as to adjust the reflection angle of the zero-degree total reflection mirror. The two zero-degree total reflection mirrors are respectively mounted on the two second optical adjustment frames. That is, the two installed zero-degree total reflection mirrors are also relative. In the present application, the number of the second rotating tables, the number of the second optical adjustment frames, and the number of the zero-degree total reflection mirrors are respectively two.

[0046] In the present application, the rotation angle of the first rotating stage, the rotation angle of the second rotating stage and the angle of the second optical adjustment frame can be adjusted respectively, so that the number of reflections of a laser beam incident on a chirped mirror between the chirped mirrors can be adjusted, and the laser beam can return from the original path after being reflected by the chirped mirror and the zero-degree total reflection mirror.

[0047] Figure 1 The optical route of a pair of chirped mirrors and a pair of zero-degree total reflection mirrors is shown. Figure 1 In the embodiment, the laser beam is first incident on the second chirped mirror M2, then reflected on the first chirped mirror M1, and then reflected on the first zero-degree total reflection mirror RM1. After being reflected by the first zero-degree total reflection mirror RM1, the laser beam returns along the original path, that is, it is reflected on the first chirped mirror M1 again, then reflected on the second chirped mirror M2, and then leaves the dispersion compensation unit from the second chirped mirror M2.

[0048] Figure 2 Another optical route of a pair of chirped mirrors and a pair of zero-degree total reflection mirrors is shown. Figure 2 In the embodiment, the laser beam is first incident on the second chirped mirror M2, then reflected on the first chirped mirror M1, then reflected on the second chirped mirror M2, and then reflected on the second zero-degree total reflection mirror RM2. After being reflected by the second zero-degree total reflection mirror RM2, the laser beam returns along the original path, that is, it is reflected on the second chirped mirror M2 again, then reflected on the first chirped mirror M1, then reflected on the second chirped mirror M2, and then leaves the dispersion compensation unit from the second chirped mirror M2.

[0049] Figure 1 In the illustrated embodiment, before being incident on the first zero-degree total reflection mirror RM1, the laser beam is reflected once between the first chirped mirror M1 and the second chirped mirror M2. Figure 2 In the embodiment shown, before incident on the second zero-degree total reflection mirror RM2, the laser beam is reflected twice between the first chirped mirror M1 and the second chirped mirror M2. In the present application, the number of reflections of the laser beam between the first chirped mirror and the second chirped mirror can be adjusted by adjusting the rotation angle of the first rotating stage, so as to obtain Figure 1 The embodiment shown or Figure 2 The embodiment shown.

[0050] The present application fixes a chirped mirror pair with a fixed dispersion amount on a rotating table, and adjusts the reflection angle of the chirped mirror by rotating the rotating table, thereby adjusting the reflection angle of the laser beam between the chirped mirrors, and then realizing the dispersion amount adjustment step length of an integer multiple of a single chirped mirror. At the same time, a zero-degree total reflection mirror is provided at the light outlet, and the laser beam is returned to the original path by adjusting the angle of the corresponding rotating table and / or adjustment frame. In this way, the dispersion amount can be adjusted in steps, and it is easy to adjust.

[0051] Optionally, in the present application, the dispersion compensation unit further includes a control element, which is used to control the rotation angle of the first rotating platform, the rotation angle of the second rotating platform, and the angle of the second optical adjustment frame.

[0052] Optionally, in the present application, the dispersion compensation unit further includes a display, which is used to display the optical path and / or dispersion amount of the laser beam, that is, the optical path of the laser beam and the compensated dispersion amount during the entire dispersion compensation process.

[0053] Optionally, in the present application, the display can be used to display the rotation angle of the first rotating stage, the rotation angle of the second rotating stage, and the angle of the second optical adjustment frame. The optical path of the laser beam can be calculated by the reflection angle of the chirped mirror used, or the optical path corresponding to different reflections can be directly queried through a comparison table.

[0054] Of course, the display can show all the above parameters at the same time, and they can be set as needed.

[0055] Each time the laser beam is reflected by the chirped mirror, a fixed dispersion amount is generated. The specific dispersion amount is determined by the different coatings, that is, the different chirped mirror models. Optionally, in this application, the dispersion amount of each chirped mirror is -35fs. 2 or -50fs 2 Of course, the dispersion amount can also be other, which can be set as needed.

[0056] Optionally, the chirped mirror is any one of a concave chirped mirror, a convex chirped mirror and a plane chirped mirror. More preferably, it is a plane chirped mirror. Optionally, the zero-degree total reflection mirror is any one of a concave zero-degree total reflection mirror, a convex zero-degree total reflection mirror and a plane zero-degree total reflection mirror. More preferably, it is a plane zero-degree total reflection mirror.

[0057] The present application further provides an optical resonant cavity, comprising any of the above-mentioned dispersion compensation units. With the above-mentioned dispersion compensation unit, the dispersion amount in the optical resonant cavity can be adjusted step by step and easily adjusted, thereby obtaining a laser beam with higher precision.

[0058] Figure 3 A method for dispersion compensation of a laser beam provided in an embodiment of the present application is shown, comprising the following steps S1 to S4.

[0059] S1: Determine the required dispersion compensation amount according to the laser beam to be compensated.

[0060] Here, the dispersion compensation amount is determined according to the laser beam to be compensated.

[0061] S2: Select at least one pair of chirped mirrors according to the dispersion compensation amount, and determine the number of reflections of the laser beam to be compensated between the at least one pair of chirped mirrors.

[0062] For example, the number of chirped mirrors may be selected first, such as two, and then the dispersion of the chirped mirrors may be selected, and then the number of reflections of the laser beam between the chirped mirrors may be calculated to achieve the desired dispersion compensation. The reflection angle of the chirped mirrors may then be adjusted to achieve the corresponding number of reflections.

[0063] As described above, each pair of chirped mirrors in the at least one pair of chirped mirrors includes two symmetrically arranged chirped mirrors. The reflection angle of the chirped mirrors can be adjusted by adjusting the rotation of the first rotating stage.

[0064] S3: The laser beam to be compensated is incident on one of at least a pair of chirped mirrors.

[0065] For example Figure 1 and Figure 2 In the embodiment, the laser beam is incident on the second chirped mirror M2. Of course, the laser beam can also be incident on the first chirped mirror M1.

[0066] S4: adjusting the reflection angles of other chirped mirrors in at least one pair of chirped mirrors and the reflection angle of the zero-degree total reflection mirror located on the light-emitting side of at least one pair of chirped mirrors, so that the number of reflections of the laser beam to be compensated between at least one pair of chirped mirrors reaches a determined number of reflections, and returns from the original path after being reflected by the zero-degree total reflection mirror.

[0067] For example, Figure 1 and Figure 2 As shown, the laser beam is incident on the second chirped mirror M2, and the reflection angle of the laser beam by the first chirped mirror M1 can be adjusted to make the laser beam present Figure 1 or Figure 2 The optical path is shown.

[0068] The method provided in the present application can achieve step-by-step adjustment of the dispersion amount, and is easy to adjust, thereby obtaining a laser beam with higher precision.

[0069] Optionally, the method provided in this application may further include:

[0070] confirming an optical path of the compensated laser beam according to a reflection angle of at least one pair of chirped mirrors; and

[0071] The vibration frequency of the compensated laser beam is confirmed based on the optical path length.

[0072] After calculating the vibration frequency, it is convenient to apply the compensated laser beam.

[0073] Obviously, the above embodiments are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A dispersion compensation unit, characterized in that: include: At least one pair of first rotating tables, wherein the two first rotating tables of each pair of first rotating tables are symmetrically arranged; A pair of second rotating tables, the two second rotating tables are symmetrically arranged; At least one pair of first optical adjustment frames, wherein the two first optical adjustment frames of each pair of first optical adjustment frames are respectively mounted on the two first rotating tables; A pair of second optical adjustment frames, each of which is mounted on the pair of second rotating platforms; at least one pair of chirped mirrors, wherein the two chirped mirrors of each pair of chirped mirrors have the same dispersion amount and are respectively mounted on the two first optical adjustment frames; and A pair of zero-degree total reflection mirrors, each zero-degree total reflection mirror is mounted on the pair of second optical adjustment frames; The rotation angle of the at least one pair of first rotating tables, the rotation angle of the pair of second rotating tables and the angle of the pair of second optical adjustment frames can be adjusted respectively, so that the number of reflections of the laser beam incident on one of the at least one pair of chirped mirrors between the at least one pair of chirped mirrors can be adjusted, and the laser beam can return from the original path after being reflected by the at least one pair of chirped mirrors and the pair of zero-degree total reflection mirrors.

2. The dispersion compensation unit according to claim 1, characterized in that: Also includes: The control element is used to control the rotation angle of the at least one pair of first rotating platforms, the rotation angle of the pair of second rotating platforms and the angle of the pair of second optical adjustment frames.

3. The dispersion compensation unit according to claim 1, characterized in that: Also includes: A display is used to display the optical path and / or dispersion amount of the laser beam.

4. The dispersion compensation unit according to claim 1, characterized in that: Also includes: The display is used to display the rotation angle of the at least one pair of first rotating platforms, the rotation angle of the pair of second rotating platforms and the angle of the pair of second optical adjustment frames.

5. The dispersion compensation unit according to claim 1, characterized in that: The dispersion of each of the at least one pair of chirped mirrors is -35 fs 2 or -50fs 2 .

6. The dispersion compensation unit according to claim 1, characterized in that: The at least one pair of chirped mirrors is any one of a concave chirped mirror, a convex chirped mirror and a planar chirped mirror.

7. The dispersion compensation unit according to claim 1, characterized in that: The pair of zero-degree total reflection mirrors is any one of a concave zero-degree total reflection mirror, a convex zero-degree total reflection mirror and a flat zero-degree total reflection mirror.

8. An optical resonant cavity, characterized in that: The dispersion compensation unit comprises any one of claims 1 to 7.

9. A method for dispersion compensation of a laser beam, characterized in that: include: Determining the required dispersion compensation amount according to the laser beam to be compensated; According to the dispersion compensation amount, at least one pair of chirped mirrors is selected, and the number of reflections of the laser beam to be compensated between the at least one pair of chirped mirrors is determined; wherein each pair of chirped mirrors in the at least one pair of chirped mirrors includes two chirped mirrors that are symmetrically arranged; Imparting the laser beam to be compensated onto one of the at least one pair of chirped mirrors; as well as Adjust the reflection angles of other chirped mirrors in the at least one pair of chirped mirrors and the reflection angle of the zero-degree total reflection mirror located on the light-emitting side of the at least one pair of chirped mirrors, so that the number of reflections of the laser beam to be compensated between the at least one pair of chirped mirrors reaches the determined number of reflections, and returns from the original path after being reflected by the zero-degree total reflection mirror.

10. The method according to claim 9, characterized in that Also includes: confirming the optical path of the compensated laser beam according to the reflection angle of the at least one pair of chirped mirrors; as well as The vibration frequency of the compensated laser beam is confirmed based on the optical path.

Images