Chirped pulse compression device and laser

Abstract

The present application provides a chirped pulse compression device and a laser, the device comprising the following components: a translational roof prism is relatively spaced from a grating and is set to be totally reflected at all angles; a reflector assembly comprises a plurality of reflectors all located between the grating and the translational roof prism; after an incident light beam hits the grating, it is diffracted by the grating to form a first light beam that is directed toward the reflector assembly along a first direction; after the first light beam is reflected by the reflector assembly multiple times and the reference plane position of the translational roof prism is translated, it is reflected back to the reflector assembly and reflected multiple times, and then it is returned to the grating in a direction symmetrical to the first direction, and then it is diffracted by the grating twice to form a second light beam that meets the grating diffraction condition. The chirped pulse compression device provided by the present application can improve the utilization rate of the grating area, increase the compressible pulse width, thereby increasing the single pulse energy of the pulse output and reducing the cost.

Description

Technical Field

[0001] The present application belongs to the technical field of laser devices, and more specifically, relates to a chirped pulse compression device and a laser. Background Art

[0002] At present, high-power, high-pulse energy ultrafast lasers reaching the femtosecond or picosecond level are widely used in precision micromachining, biomedicine, scientific research and other fields due to their narrow pulse width, large single pulse energy, and high repetition frequency. In order to obtain high-power, high-pulse energy ultrafast lasers, the industry usually uses chirped pulse amplification (CPA). This technology first widens the seed pulse width to hundreds of picoseconds or nanoseconds, increases the average power through the amplifier stage, and then further compresses the pulse width to femtoseconds or picoseconds through a chirped pulse compression device. Here, the size of the laser's widened pulse width is an important factor in determining the single pulse energy and peak power of the ultrafast laser, that is, the wider the widened pulse width, the higher the laser single pulse energy that can be obtained at the same peak power, and the greater the peak power after compression. However, the wider the laser pulse width, the larger the spot size after grating diffraction in the chirped pulse compression device. Due to the size of the chirped pulse compression device, especially the limitation of the grating area utilization, the existing chirped pulse compression device is not only costly, but its design also limits the compressible pulse width, which in turn makes it impossible to further increase the single pulse energy and peak power of the ultrafast laser. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a chirped pulse compression device to solve the technical problems existing in the prior art of low grating area utilization, large size and high cost of the grating in the chirped pulse compression device.

[0004] To achieve the above purpose, the technical solution adopted in this application is: to provide a chirped pulse compression device, comprising:

[0005] Grating;

[0006] A translational roof prism, wherein the reflection surface of the translational roof prism is spaced relative to the ruled line plane of the grating and is arranged for total reflection at all incident angles; and

[0007] A reflector assembly, the reflector assembly comprising a plurality of reflectors, wherein the plurality of reflectors are located between the grating and the translational roof prism;

[0008] The plane where the light path of the incident light after entering the grating is located is taken as the reference plane, the reference plane is perpendicular to the ruled line plane of the grating, and the line on the reference plane perpendicular to the ruled line plane of the grating is taken as the normal line; after the incident light enters the grating, it is diffracted by the grating to form a first light emitted toward the reflector assembly along a first direction, the first light is reflected by the reflector assembly for multiple times, translated along the reference plane position by the translational roof prism, reflected back to the reflector assembly, reflected by the reflector assembly for multiple times again, finally reflected by one of the reflectors along a direction symmetrical to the first direction relative to the normal line, and then returned to the grating, and then diffracted by the grating for the second time to form a second light that satisfies the grating diffraction conditions together with the first light.

[0009] Optionally, the reflector assembly includes two reflectors, which are a first reflector and a second reflector whose reflective surfaces are parallel and opposite to each other, the grating is located between a plane where the first reflector is located and a plane where the second reflector is located, and the first reflector and the second reflector are both perpendicular to the ruled line plane of the grating.

[0010] Optionally, the translational roof prism has a first reflecting surface and a second reflecting surface which are perpendicular to each other, and the first reflecting surface and the second reflecting surface are both set for total reflection at all angles, the first reflecting surface is parallel to the ruled plane of the grating, and the second reflecting surface is parallel to both the first reflector and the second reflector.

[0011] Optionally, the first reflector and the second reflector are both arranged to provide total reflection at all angles.

[0012] Optionally, the same plane where the optical paths of the first light ray and the second light ray are located is taken as a reference plane, and a straight line perpendicular to the reference plane is taken as a Z axis;

[0013] The chirped pulse compression device also includes a raised roof prism, the second light ray enters the raised roof prism, and forms a third light ray after secondary reflection by the raised roof prism, the third light ray moves a preset distance relative to the second light ray along the direction perpendicular to the reference plane, and enters the grating again along the direction opposite to the second light ray.

[0014] Optionally, when the grating is a transmission type grating, the raised roof prism is arranged on a side of the grating away from the translational roof prism;

[0015] When the grating is a reflective grating, the raised roof prism is arranged between the grating and the second reflector.

[0016] Optionally, the intersection line of the reference plane and the ruled line plane of the grating is taken as the X-axis, and the straight line on the reference plane perpendicular to the X-axis is taken as the Y-axis;

[0017] The translational roof prism, the second reflector and the raised roof prism can all be moved relative to the grating on the X-axis, and the translational roof prism, the second reflector and the raised roof prism can all be moved relative to the grating in the Y-axis direction; the translational roof prism can rotate around the Z-axis, and the raised roof prism can rotate around the Z-axis; the raised roof prism can move along the Z-axis relative to the grating.

[0018] The present application also proposes a laser, comprising the chirped pulse compression device as described above.

[0019] The chirped pulse compression device provided by the present application has the beneficial effect that: since a plurality of reflectors are provided between the grating and the translational roof prism, and the first light ray can be reflected back into the grating in a direction symmetrical to the normal line relative to the first direction after multiple reflections by the reflector assembly, translation of the translational roof prism along the reference plane, and multiple reflections by the reflector assembly, the first light ray can be incident on the grating symmetrically with the first light ray, thereby overcoming the defect that the grating area of ​​the conventional compression system cannot be utilized due to the incident divergence angle and position translation, thereby improving the utilization rate of the grating area, thereby increasing the maximum pulse width that can be compressed, and increasing the single pulse energy of the laser; at the same time, through multiple reflections by the reflector assembly, the space of the chirped pulse compression device can be saved, and its size can be reduced, thereby achieving the purpose of reducing the cost of the laser and greatly improving the single pulse energy of the laser. In other words, compared to the traditional single grating compression system design, the technical solution of the present application adopts a reflector assembly that can return the first light to the grating in a direction symmetrical to the normal, which can achieve high pulse energy, adjustable pulse width, and low-cost lasers on the one hand; on the other hand, it overcomes the disadvantage of the traditional single grating compression system being large in size, which can greatly improve the pulse energy of the laser and reduce the cost of the laser. Of course, compared to the traditional dual grating compression system, the present application only needs one grating to achieve the purpose of performance improvement, which can save another expensive grating, while overcoming the problem of large size of the dual grating system, greatly saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 paying creative labor.

[0021] Figure 1 It is a schematic diagram of the optical path structure of a single grating compression device in the prior art;

[0022] Figure 2 It is a structural schematic diagram of a double grating compression device in the prior art;

[0023] Figure 3 A schematic diagram of the structure of a chirped pulse compression device provided in an embodiment of the present application;

[0024] Figure 4 A schematic diagram of a grating full coverage structure in a chirped pulse compression device provided in an embodiment of the present application;

[0025] Figure 5 Schematic diagram of various directions in which other components of the chirped pulse compression device provided in an embodiment of the present application move and rotate relative to the grating;

[0026] Figure 6 A schematic diagram of the optical path structure of a chirped pulse compression device provided in another embodiment of the present application.

[0027] Description of Figure Numbers:

[0028] Label name Label name 11 Incident light 12 First Light 13 Second ray 2 Grating 3 Translational Roof Prism 4 Raising the roof prism 5 First reflector 6 Second reflector DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by 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.

[0030] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0031] It should also be noted that the directional terms such as left, right, up and down in the embodiments of the present application are merely relative concepts or are based on the normal use status of the product, and should not be considered as restrictive.

[0032] Embodiments of the present application are described in detail below, and examples of the embodiments 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.

[0033] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 the present application.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, 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 application can be understood according to specific circumstances.

[0036] An embodiment of the present application provides a chirped pulse compression device.

[0037] See also Figures 3 to 5 In one embodiment, the chirped pulse compression device includes a grating 2, a translational roof prism 3, and a reflector assembly. Specifically, the reflective surface of the translational roof prism 3 is relatively spaced from the ruled plane of the grating 2 and is fully reflected at each incident angle; the reflector assembly includes a plurality of reflectors, and the plurality of reflectors are located between the grating 2 and the translational roof prism 3. Among them, the plane where the light path of the incident light after entering the grating 2 is located is taken as the reference plane, the reference plane is perpendicular to the ruled line plane of the grating 2, and the line on the reference plane that is perpendicular to the ruled line plane of the grating 2 is taken as the normal line; after the incident light 11 hits the grating 2, it is diffracted by the grating 2 to form a first light 12 that is emitted toward the reflector assembly along a first direction, the first light 12 is reflected by the reflector assembly for multiple times, translated along the reference plane position by the translational roof prism 3, and then reflected back to the reflector assembly, after being reflected by the reflector assembly for multiple times again, it is finally reflected by one of the reflectors and returned to the grating 2 in a direction symmetrical to the normal line relative to the first direction, and then diffracted by the grating 2 for the second time to form a second light 13 that meets the grating diffraction condition.

[0038] It should be noted that the existing conventional chirped pulse compression devices are mainly divided into the following categories: Figure 1 The single grating compression system shown and Figure 2 The double grating compression system shown in Figure 1. Figure 1 The figure on the left shows a single transmission grating compression system, and the figure on the right shows a single reflection grating compression system. For a single grating system, in order to improve the utilization rate of the grating area, it is often achieved by adjusting the incident position of the incident laser to the edge of the grating area of ​​grating 2 as much as possible. However, on the one hand, due to the certain divergence angle of the incident laser, its incident position cannot be at the edge of the grating 2 in the true sense, resulting in a decrease in the utilization rate of the grating area of ​​grating 2; on the other hand, the translation of the roof prism 3 will cause the light diffracted by grating 2 for the first time to be translated a certain distance and then return to grating 2 again, which will inevitably make the grating area between the first incident position of the incident laser and the second incident position, that is, the grating area of ​​a translation distance length, unusable. Figure 2 The left figure in the figure shows a transmission type double grating compression system, and the right figure shows a reflection type double grating compression system. Although in the double grating compression system, the problem of incident laser divergence does not need to be considered, the position translation caused by the translation of the roof prism 3 still needs to be considered. This position translation can still make the grating area of ​​a translation distance length unusable. The grating area utilization rate is an important factor in determining the compressible pulse width, and it is also an important factor in determining the peak power and single pulse energy of the ultrafast laser system.

[0039] Furthermore, for the traditional single-grating compression system, its compression mainly relies on the spacing between the translational roof prism 3 and the grating 2 to control the pulse width, and the distance compressed to the minimum pulse width is proportional to the pulse width that needs to be compressed. This means that to obtain higher peak power, a longer compression distance is required, that is, a larger compressor size, which will greatly reduce the flexibility of the laser and increase the cost of the laser. The dual-grating compression system controls the compressed pulse width by the spacing between the two gratings 2, and the spacing is consistent with the single-grating compression system under the same pulse width. However, since two gratings are required in this compression system, and the price of gratings is very expensive, this design will also lead to a significant increase in cost.

[0040] In addition, the chirped pulse compression device of the present application is mainly applicable to the field of ultrashort pulse lasers, and can be applied to traditional CPA systems, including but not limited to ultrafast lasers with various gain media such as optical fiber or solid. Here, the incident light 11 is a laser, and its incident direction is variable; the grating 2 is a compression grating with an optional grating constant; the translational roof prism 3 is usually composed of two reflective mirrors glued to each other perpendicularly. In this embodiment, the reflector assembly includes two reflectors, and the two reflectors are respectively a first reflector 5 and a second reflector 6 with parallel and opposite reflective surfaces. The grating 2 is located between the plane where the first reflector 5 is located and the plane where the second reflector 6 is located, and the first reflector 5 and the second reflector 6 are perpendicular to the grating 2. The first light 12 is reflected by the first reflector 5 and the second reflector 6 for multiple times and then enters one of the reflective mirrors, and then is reflected by the other reflective mirror and enters the first reflector 5 and the second reflector 6. Since the two reflective mirrors are perpendicular to each other, the first light 12 can be translated along a preset direction for a preset distance on the same horizontal plane after being reflected twice by the two reflective mirrors. Furthermore, in all the drawings, the dotted lines represent propagation paths in which actual multiple reflections of light are simplified to a single reflection.

[0041] Based on this structural design, in the present embodiment, since a first reflector 5 and a second reflector 6 which are perpendicular to the ruled line plane of the grating 2 are provided between the grating 2 and the translational roof prism 3, and the grating 2 is located between the first reflector 5 and the second reflector 6, the first light 12 can be reflected back into the grating 2 in a direction symmetrical to the normal line relative to the first direction after multiple reflections by the first reflector 5 and the second reflector 6, the translational position of the translational roof prism 3 along the reference plane, and multiple reflections by the first reflector 5 and the second reflector 6. Therefore, this method of incident on the grating symmetrically with the first light 12 can overcome the defect that the grating area of ​​the conventional compression system cannot be utilized due to the incident divergence angle and position translation, thereby improving the utilization rate of the grating area of ​​the grating 2, thereby increasing the maximum pulse width that can be compressed, and increasing the single pulse energy of the laser; at the same time, through multiple reflections by the first reflector 5 and the second reflector 6, the space of the chirped pulse compression device can be saved and its size can be reduced, thereby achieving the purpose of reducing the cost of the laser and greatly improving the single pulse energy of the laser. In other words, compared to the traditional single grating compression system design, the present application uses a reflector assembly that can return the first light to the grating in a direction symmetrical to the normal direction. On the one hand, it helps to achieve a high single pulse energy, adjustable pulse width, and low-cost laser; on the other hand, through the multiple reflections of the light by the two reflectors, it overcomes the disadvantage of the large size of the traditional single grating compression system, which can greatly improve the single pulse energy of the laser and reduce the cost of the laser. Of course, compared to the traditional dual grating compression system, the present application only needs one grating 2 to achieve the purpose of performance improvement, thereby eliminating another expensive grating, while overcoming the problem of large size of the dual grating system, greatly saving costs.

[0042] See also Figure 3 In this embodiment, the first reflector 5 and the second reflector 6 are both perpendicular to the ruled plane of the grating 2. However, in the technical solution of the present application, it is not limited to the case where the first reflector 5 and the second reflector 6 are both perpendicular to the grating 2. More reflectors can be used, and different angles can be set as long as the condition that the first light 12 and the light that re-enters the grating 2 after reflection are symmetrical about the normal line perpendicular to the ruled plane of the grating 2 is met. However, in this embodiment, the setting of the two reflectors perpendicular to the ruled plane of the grating 2 can make it easier to adjust the spacing between the reflectors and the grating 2 or the translational roof prism 3.

[0043] See also Figure 3In this embodiment, the translational roof prism 3 has a first reflection surface and a second reflection surface that are perpendicular to each other, the first reflection surface is parallel to the line plane of the grating 2, and the second reflection surface is parallel to the first reflector 5 and the second reflector 6. In this way, it is not only more convenient to adjust the distance between each other and improve the utilization rate of the grating area of ​​the grating 2, but also conducive to further reducing the size of the entire chirped pulse compression device, thereby helping to reduce the cost of the laser. Of course, in other embodiments, for example Figure 5 As shown, the first reflection surface and the second reflection surface of the translational roof prism 3 can also be set at other angles with the ruled plane of the grating 2, as long as the optical path of the light satisfies the condition that the first light 12 and the light that re-enters the grating 2 after reflection are symmetrical about the normal perpendicular to the ruled plane of the grating 2.

[0044] Furthermore, in this embodiment, the first reflector 5 and the second reflector 6 are both set to fully reflect at all angles, thereby ensuring the complete reflection of the first light 12 on the first reflector 5, the second reflector 6 and the translational roof prism 3, and reducing the spacing between these optical components as much as possible, which is very beneficial to reducing the size of the chirped pulse compression device and reducing the cost.

[0045] See also Figure 3 and Figure 4 In this embodiment, the same plane where the optical paths of the first light 12 and the second light 13 are located is taken as the reference plane, that is, Figure 3 and Figure 4 The plane where the paper surface is located in the figure is the Z axis, and the straight line perpendicular to the reference plane is the Z axis; the chirped pulse compression device also includes a raised roof prism 4, the second light 13 is incident on the raised roof prism 4, and is reflected twice by the raised roof prism 4 to form a third light, the third light moves a preset distance relative to the second light 13 in a direction perpendicular to the reference plane, and is incident on the grating 2 again in a direction opposite to the second light, so that the light can propagate on another reference plane with a different Z axis height compared to the original reference plane, so that the light path returns to the original path to achieve the compressed circular spot output. Here, each time the second light 13 emitted from the grating 2 only passes through the raised roof prism 4 that moves up and down, and then is reflected back into the grating 2. It should be noted that the purpose of raising the roof prism 4 is to raise the light from the reference plane to another plane to realize the return of the light along its original path, and then separate the compressed light. That is, if the raised roof prism 4 is replaced by a plane reflector, the compressed light path still holds, but the subsequent compressed laser output is not easy to process, so the function is realized by raising the roof prism 4.

[0046] It should be noted here that the commonly used gratings are made by engraving a large number of parallel grooves on a glass sheet. A refined grating has thousands or even tens of thousands of grooves within a width of 1 cm, so the price of the grating is very expensive. Gratings are usually divided into two categories. One is that the grooves are opaque and the smooth part between the two grooves is transmissive. This is equivalent to forming a slit between the two grooves that can be used for light diffraction. This grating that uses the diffraction of transmitted light is called a transmission grating; the other is a reflective grating, which is mainly a grating that uses the diffraction of reflected light between two grooves. For example, many parallel grooves are engraved on the surface of a glass sheet coated with a metal layer, and the smooth metal surface between the two grooves can reflect light. Specifically, Figure 3 As shown, in this embodiment, when the grating 2 is a transmission type grating, according to the actual optical path design, the raised roof prism 4 should be arranged on the side of the grating 2 away from the translational roof prism 3; Figure 6 In another embodiment shown, when the grating 2 is a reflective grating, the raised roof prism 4 should be disposed between the grating 2 and the second reflector 6 according to the actual optical path design.

[0047] Specifically, Figure 3 and Figure 4 As shown, when the grating 2 is a transmission type grating, first, the incident light 11 is incident on the grating 2, and forms the first light 12 after the first diffraction of the grating 2; then, the first light 12 is incident on the reflecting surface of the first reflector 5, and after multiple reflections by the first reflector 5 and the second reflector 6, enters the translational roof prism 3; then, the translational roof prism 3 translates the light on the same plane for a certain distance and then returns in parallel; then, after the light emitted from the translational roof prism 3 enters the second reflector 6, it can be reflected multiple times by the second reflector 6 and the first reflector 5, and finally the second reflector 6 reflects the light back to the grating 2, and performs a second diffraction to form a second light 13 that meets the grating diffraction condition. The second light 13 then enters the lifting roof prism 4, and after moving a certain distance in the Z-axis direction, it enters the grating 2 again for diffraction, so that the theoretical return of the light path after lifting is realized and the light is compressed. Of course, in another embodiment in which the grating 2 is a reflection type grating, its light path is as follows Figure 6 As shown by the dotted line with an arrow in FIG. , no further details are given here.

[0048] See also Figure 5 In this embodiment, when looking down at the grating 2 on the same reference plane, the dotted line represents the grating 2, and the intersection line of the reference plane and the ruled line plane of the grating 2 is taken as the X-axis, that is, Figure 5 The direction indicated by the double arrow solid line with the reference number 52; the direction perpendicular to the X-axis on the reference plane, i.e., the normal direction of the line plane of the grating 2, is the Y-axis, i.e. Figure 5The direction is indicated by the double-arrow solid line labeled 51 in the figure; the direction of the first light 12 is the direction indicated by the double-arrow solid line labeled 53 in the figure, and the double-arrow solid line labeled 54 indicates the direction perpendicular to the double-arrow solid line labeled 53 on the reference plane; the direction of the second light 13 is the direction indicated by the double-arrow solid line labeled 55 in the figure, and the double-arrow solid line labeled 56 indicates the direction perpendicular to the double-arrow solid line labeled 55 on the reference plane; the direction labeled 57 is the rotation direction perpendicular to the reference plane, that is, the direction of rotation around the Z axis.

[0049] Here, in order to improve the utilization rate of the grating area of ​​the grating 2, it is even possible to achieve the following Figure 4 The grating area shown is fully covered, the translational roof prism 3, the second reflector 6 and the elevated roof prism 4 can all move relative to the grating 2 on the X-axis, and the translational roof prism 3, the second reflector 6 and the elevated roof prism 4 can also move relative to the grating 2 on the Y-axis; the translational roof prism 3 can rotate around the Z-axis, and the elevated roof prism 4 can also rotate around the Z-axis; the elevated roof prism 4 can move relative to the grating 2 along the Z-axis. Specifically, as Figures 3 to 5 As shown, in order to meet the requirement of full coverage of the grating area, the second reflector 6 can be adjusted in the directions marked 52 and 51, so that the state of the grating 2 reflected by the grating 2 entering the grating 2 is as shown in FIG. Figure 4 Then, the second light 13 is formed by the secondary diffraction of the grating 2, and the second light 13 enters the raised roof prism 4. At the same time, the raised roof prism 4 can move in the directions marked 55 and 56 and rotate in the direction marked 57 according to the previous adjustment result, so as to adjust the position of the raised roof prism 4, so as to ensure that the second light 13 can be injected into the raised roof prism 4 and return to the original path after a certain distance translation along the Z axis. Of course, the above is only an adjustment method for the chirped pulse compression device with a transmission grating. Figure 6 In another embodiment shown, the adjustment method of the chirped pulse compression device with a reflective grating is basically the same as the adjustment method of the compression device with a transmissive grating, and will not be described in detail here.

[0050] Furthermore, the design that each optical element can be adjusted in position relative to the grating 2, in addition to having the aforementioned functions of improving the utilization rate of the grating area of ​​the grating 2 and increasing the maximum pulse width that can be compressed, also has the function of optimizing the dispersion adjustment to achieve higher single pulse energy and higher peak power. It can be understood that, since dispersion matching is an important factor in obtaining the narrowest compressed pulse width in chirped pulse amplification technology, and is also the main factor determining the peak power after compression, the adjustable dispersion of the compressor is also an indispensable condition for obtaining high peak power. Among them, pulse width adjustment is mainly achieved through the second-order dispersion of the chirped pulse compression device, that is, by adjusting the translational roof prism 3. Specifically, the roof prism 3 can be translated as follows: Figure 5In addition, in the design of the CPA compression device, it is usually hoped that the second-order and third-order dispersions are compensated at the same time, so as to achieve a better compression effect. The second-order dispersion of the compression device can be easily compensated by the compression grating 2, but the compression grating 2 also brings additional positive third-order dispersion, and the ratio of the additional third-order dispersion to the second-order dispersion is a function of the incident light angle. Usually, the ratio can be optimized to an optimal value by adjusting the angle at which the incident light 11 enters the grating 2, thereby ensuring that the CPA compression device can achieve the best compression effect. Of course, changing the ratio of the third-order dispersion to the second-order dispersion will change the angle of the incident light 11, and at the same time change the direction of the first light 12 diffracted by the grating 2 for the first time. At this time, it is only necessary to sequentially adjust the second reflector 6 in the directions marked 51 and 52, adjust the translational roof prism 3 in the directions marked 53 and 54, and adjust the elevation roof prism 4 in the directions marked 55, 56, and 57 to achieve the optimization of dispersion compensation. In other words, the technical solution of the present application can control the second-order and third-order dispersion by moving the second reflector 6 and the translational roof prism 3, and control the ratio of the third-order and second-order dispersion by changing the laser incident angle of the incident light 11 and adjusting the elevation roof prism 4, the second reflector 6, and the translational roof prism 3 at the same time. In this way, the chirped pulse compression device can achieve continuous adjustment of the second-order and third-order dispersions by adjusting the positions of the optical components, and achieve continuous adjustment of the ratio of the third-order dispersion to the second-order dispersion by changing the angle of the incident light 11, thereby achieving the technical purpose of achieving optimal dispersion compensation, i.e., dispersion optimization, and narrowing the compressed pulse width, thereby providing the possibility of realizing a pulse width adjustable ultrafast laser with higher single pulse energy, higher peak power, lower cost, and more compact structure.

[0051] In summary, the chirped pulse compression device can increase the maximum pulse width that can be compressed by improving the utilization rate of the grating area of ​​grating 2 on the one hand, and can achieve higher single pulse energy and higher peak power by adjusting the dispersion optimization on the other hand. In this way, based on the chirped pulse compression device, it is possible to further design and realize a high-power ultrafast laser with adjustable pulse width, high grating area utilization, small size and low cost.

[0052] The present application also proposes a laser, which includes a chirped pulse compression device. The specific structure of the chirped pulse compression device refers to the above-mentioned embodiment. Since the present laser adopts all the technical solutions of all the above-mentioned embodiments, it also has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0053] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A chirped pulse compression device, characterized in that: include: Grating; A translational roof prism, wherein the reflection surface of the translational roof prism is spaced relative to the ruled line plane of the grating and is arranged for total reflection at all incident angles; and A reflector assembly, wherein the reflector assembly comprises two reflectors, wherein the two reflectors are respectively a first reflector and a second reflector whose reflective surfaces are arranged parallel to each other, the grating is located between a plane where the first reflector is located and a plane where the second reflector is located, and both the first reflector and the second reflector are perpendicular to a line plane of the grating, and both the reflectors are located between the grating and the translational roof prism; The plane where the light path of the incident light after entering the grating is located is taken as the reference plane, the reference plane is perpendicular to the line plane of the grating, and the line on the reference plane perpendicular to the line plane of the grating is taken as the normal line; after the incident light enters the grating, it is diffracted by the grating to form a first light emitted toward the reflector assembly along a first direction, the first light is reflected by the reflector assembly for multiple times, translated along the reference plane position by the translational roof prism, and then reflected back to the reflector assembly, after being reflected by the reflector assembly for multiple times again, it is finally reflected by one of the reflectors and returned to the grating along a direction symmetrical to the first direction relative to the normal line, and then diffracted by the grating for the second time to form a second light satisfying the grating diffraction condition; The straight line perpendicular to the reference plane is taken as the Z axis; the chirped pulse compression device further comprises a raised roof prism, the second light is incident on the raised roof prism, and is reflected twice by the raised roof prism to form a third light, the third light moves a preset distance relative to the second light in the direction perpendicular to the reference plane, and is incident on the grating again in the direction opposite to the second light; The intersection line of the reference plane and the ruled line plane of the grating is taken as the X-axis, and the straight line on the reference plane perpendicular to the X-axis is taken as the Y-axis; the translational roof prism, the second reflector and the raised roof prism can all be moved relative to the grating on the X-axis, and the translational roof prism, the second reflector and the raised roof prism can all be moved relative to the grating in the Y-axis direction; the translational roof prism can rotate around the Z-axis, and the raised roof prism can rotate around the Z-axis; the raised roof prism can move along the Z-axis relative to the grating.

2. The chirped pulse compression device according to claim 1, characterized in that: The translational roof prism has a first reflection surface and a second reflection surface which are perpendicular to each other, and the first reflection surface and the second reflection surface are both arranged for total reflection at all angles, the first reflection surface is parallel to the ruled line plane of the grating, and the second reflection surface is parallel to the first reflector and the second reflector.

3. The chirped pulse compression device according to claim 1, characterized in that: The first reflector and the second reflector are both arranged to provide total reflection at all angles.

4. The chirped pulse compression device according to any one of claims 1 to 3, characterized in that: When the grating is a transmission type grating, the raised roof prism is arranged on a side of the grating away from the translational roof prism; When the grating is a reflective grating, the raised roof prism is arranged between the grating and the second reflector.

5. A laser, characterized in that: It comprises the chirped pulse compression device as claimed in any one of claims 1 to 4.

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