A high power continuous wave single frequency tunable titanium sapphire laser

Abstract

The application discloses a high-power continuous-wave single-frequency tunable titanium sapphire laser, which comprises a resonant cavity and at least two titanium sapphire crystals, the resonant cavity comprises at least one adjacent concave-convex mirror pair in an optical path and an output coupling mirror, the titanium sapphire crystals are arranged at waist spots between the concave-convex mirror pair, and each titanium sapphire crystal has an independent pump source. The application inserts multiple titanium sapphire crystals with independent pump sources into the resonant cavity, and arranges the titanium sapphire crystals at the waist spots between the two concave-convex mirrors to realize population inversion, solves the problem that the output power of the titanium sapphire laser is limited due to the limited output power of the pump source through multi-end pumping, meanwhile, the multiple concave-convex mirrors effectively expand the pumpable ports, avoid crystal damage caused by a titanium sapphire crystal driven by a very high-power pump source, and provide an effective way for realizing high-power continuous-wave single-frequency titanium sapphire laser output.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser, more particularly, to a high-power continuous-wave single-frequency tunable Ti:sapphire laser. BACKGROUND

[0002] The all-solid-state continuous-wave single-frequency Ti:sapphire laser is widely used in many scientific research fields such as atomic trapping and cooling, atomic clock, precise measurement and high-resolution spectroscopy due to its advantages of narrow linewidth, low frequency noise, perfect beam quality and high power stability. In recent years, with the rapid development of quantum computing and quantum communication, the quantum system based on atoms has put forward higher requirements for the output power of the all-solid-state continuous-wave single-frequency Ti:sapphire laser. In the field of continuous-wave single-frequency tunable Ti:sapphire laser, the all-solid-state continuous-wave single-frequency 532nm green laser is the best choice for Ti:sapphire pump source due to its low noise, perfect beam quality, narrow linewidth and good stability.

[0003] However, the maximum output power of a single all-solid-state continuous-wave single-frequency 532nm laser is limited, only in the order of 30W, which cannot provide sufficient pumping for the Ti:sapphire crystal. The upper level lifetime of the Ti:sapphire crystal is very short, only 13.2μs, and a small waist spot is required for the pump source to achieve population inversion. The higher the pump power, the larger the required waist spot. Therefore, even if there is a very high power pump source, the crystal will be damaged because it cannot withstand high power density laser.

[0004] In addition, the Ti:sapphire crystal itself has the problem of incomplete pump absorption, which cannot completely and efficiently absorb the existing pump. SUMMARY

[0005] The present application provides a high-power continuous-wave single-frequency tunable Ti:sapphire laser, which inserts multiple Ti:sapphire crystals with independent pump sources into the resonant cavity, and sets the Ti:sapphire crystals on the waist spot between the two concave-convex mirrors to achieve population inversion. The multi-end pumping solves the problem that the output power of the pump source is limited, which limits the output power of the Ti:sapphire laser, and the multiple concave-convex mirrors effectively expand the pumpable ports, avoiding the damage of the crystal caused by the high-power pump source, which provides an effective way to realize high-power continuous-wave single-frequency Ti:sapphire laser output.

[0006] The present application provides a high-power continuous-wave single-frequency tunable Ti:sapphire laser, which includes a resonant cavity and at least two Ti:sapphire crystals, the resonant cavity includes at least one pair of concave-convex mirrors adjacent in the optical path and an output coupling mirror, and the Ti:sapphire crystals are arranged at the waist spot between the concave-convex mirror pairs, each Ti:sapphire crystal has an independent pump source.

[0007] Preferably, each titanium sapphire crystal has an independent residual pump back component.

[0008] Preferably, the resonant cavity is a figure-of-eight ring cavity.

[0009] Preferably, the figure-of-eight ring cavity comprises at least two adjacent concave-convex mirror pairs in the light path, and one titanium sapphire crystal is arranged between each concave-convex mirror pair.

[0010] Preferably, in each concave-convex mirror pair, a pump source is arranged on the outer side of the first concave-convex mirror, and a residual pump back component is arranged on the outer side of the second concave-convex mirror.

[0011] Preferably, the figure-of-eight ring cavity comprises at least two adjacent concave-convex mirror pairs in the light path, and two titanium sapphire crystals are arranged between the at least two concave-convex mirror pairs, a pump source is arranged on the outer side of each of the two concave-convex mirrors, and two residual pump back components are arranged between the two titanium sapphire crystals.

[0012] Preferably, one titanium sapphire crystal is arranged between the at least two concave-convex mirror pairs.

[0013] Preferably, the residual pump back component is a combination of a plano-convex lens with a preset focal length and a 0-degree mirror or a concave mirror with a preset curvature.

[0014] Preferably, the pump source is a full-solid-state continuous-wave single-frequency 532 nm laser.

[0015] Preferably, the laser output by the pump source matches the gain absorption spectrum line of the titanium sapphire crystal.

[0016] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings incorporated in and forming a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the application.

[0018] Figure 1 Structure schematic diagram of an example of a high-power continuous-wave single-frequency tunable titanium sapphire laser provided by the present application;

[0019] Figure 2 Optical beam transmission characteristics of the resonant cavity in the example of Figure 1

[0020] Figure 3 Output power curve of the high-power continuous-wave single-frequency tunable titanium sapphire laser under different pump powers in the example of Figure 1

[0021] Figure 4 Figure 1 ​​​wavelength tuning curve obtained by rotating the tuning element in the example of

[0022] Figure 5 For Figure 1 long-term power stability and longitudinal mode structure of a titanium sapphire laser in the example of

[0023] Figure 6 Structure schematic diagram of another example of high-power continuous-wave single-frequency tunable titanium sapphire laser provided in the present application;

[0024] Figure 7 Structure schematic diagram of still another example of high-power continuous-wave single-frequency tunable titanium sapphire laser provided in the present application;

[0025] Figure 8 Structure schematic diagram of yet another example of high-power continuous-wave single-frequency tunable titanium sapphire laser provided in the present application. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions, and numerical values set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

[0027] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the scope of the application, its application, or uses.

[0028] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, where appropriate, techniques, methods, and devices should be considered part of the description of the present application.

[0029] In all of the compositions and methods shown and discussed herein, any specific values should be interpreted as merely exemplary, and are not intended to be limiting. Thus, other examples of the exemplary embodiments can have different values.

[0030] The application provides a high-power continuous-wave single-frequency tunable titanium sapphire laser, a plurality of titanium sapphire crystals with independent pump sources are inserted into a resonant cavity, and the titanium sapphire crystals are arranged on a waist spot between two concave-convex mirrors to realize population inversion, the problem that the output power of the titanium sapphire laser is limited due to the limited output power of the pump source is solved by multi-end pumping, meanwhile, the plurality of concave-convex mirrors effectively expand the pumpable ports, and the thermal damage of the crystal caused by the high-power pump source is avoided, thereby providing an effective way for realizing high-power continuous-wave single-frequency titanium sapphire laser output. In the application, each titanium sapphire crystal has an independent residual pump back injection component, the titanium sapphire crystal can efficiently absorb the residual pump light for the second time, the problem of incomplete pump absorption of the titanium sapphire crystal is solved, the pump utilization rate is greatly improved, and the output power of the titanium sapphire laser is increased.

[0031] The high-power continuous-wave single-frequency tunable titanium sapphire laser provided by the application comprises a resonant cavity, at least two titanium sapphire crystals, a wideband optical isolator, a wide-tuning element and a frequency selection element, the resonant cavity comprises at least one pair of concave-convex mirrors adjacent in an optical path and an output coupling mirror, the titanium sapphire crystals are arranged at waist spots between the concave-convex mirror pairs, and each titanium sapphire crystal has an independent pump source.

[0032] Preferably, the two concave-convex mirrors in each concave-convex mirror pair have the same radius of curvature and are arranged at an angle, both surfaces of the concave-convex mirror are coated with a high-transmission film for pump laser, and the inner surface is coated with a high-reflection film for oscillation laser.

[0033] As an embodiment, the titanium sapphire crystal is a gain crystal cut at Brewster angle, which can be a sheet titanium sapphire crystal, a rod titanium sapphire crystal or a multi-piece combined titanium sapphire crystal.

[0034] As an embodiment, the pump source is a full-solid-state continuous-wave single-frequency 532nm laser.

[0035] As an embodiment, the resonant cavity adopts an end-pumping or side-pumping mode.

[0036] Preferably, the laser output by the pump source matches the gain absorption spectrum of the titanium sapphire crystal, and has a beam quality close to the diffraction limit, so that a small focused waist spot can be realized in a long distance, and a high pump rate is beneficial to be obtained.

[0037] Specifically, a coupling lens group is arranged at the rear end of each pump source to focus the pump light beam in the titanium sapphire crystal, so as to realize mode matching of the in-cavity oscillation light and the pump light at the titanium sapphire crystal, and the size of the waist spot of the oscillation light in the center of the gain crystal is controlled to ensure that the titanium sapphire laser can output a high-power TEM00 mode.

[0038] As an embodiment, the coupling lens group is a telescope imaging system, which can complete the mode matching of the pump light and the oscillation light.

[0039] Preferably, each titanium sapphire crystal has an independent residual pump injection component.

[0040] It can be understood that the resonant cavity can be a ring cavity, a standing wave cavity, etc. In the resonant cavity, a smaller waist spot is formed on the light path between the two concave-convex mirrors, and a larger waist spot is formed on the other light path (between the concave-convex mirror and the plane mirror). The smaller waist spot is used to set the titanium sapphire crystal, and the larger waist spot is used to set the wideband optical isolator, the wide tuning element, and the frequency selection element. The upper level lifetime of the titanium sapphire crystal is very short, so a high enough pump rate is required to achieve population inversion. In this application, multiple titanium sapphire crystals are placed in the resonant cavity, thereby realizing high-power output of the laser.

[0041] As an embodiment, the resonant cavity is a herringbone-shaped ring cavity, which can be a four-mirror ring cavity with a herringbone-shaped light path, or a ring cavity with multiple herringbone-shaped light paths (i.e., a multi-layered herringbone cavity), such as an eight-mirror ring cavity, a six-mirror ring cavity, etc. The herringbone-shaped ring cavity expands the number of positions for placing titanium sapphire crystals through the concave-convex mirror pairs, greatly increasing the number of titanium sapphire crystals in the resonant cavity and greatly improving the power enhancement space of the titanium sapphire crystals.

[0042] Embodiment 1

[0043] As an embodiment, the herringbone-shaped ring cavity includes at least two adjacent concave-convex mirror pairs in the light path, and each concave-convex mirror pair is provided with a titanium sapphire crystal.

[0044] On this basis, preferably, each titanium sapphire crystal has a residual pump injection component. Specifically, in each concave-convex mirror pair, the outer side of the first concave-convex mirror is provided with a pump source, and the outer side of the second concave-convex mirror is provided with a residual pump injection component.

[0045] In this embodiment, the residual pump injection component is a combination of a plano-convex lens with a preset focal length and a 0-degree mirror or a concave mirror with a preset curvature.

[0046] Figure 1 An example of a six-mirror ring cavity in this embodiment is shown. As shown in FIG. 1, the six-mirror ring cavity includes six mirrors, i.e., a first mirror 101, a second mirror 102, a third mirror 103, a fourth mirror 104, a fifth mirror 105, and a sixth mirror 106. The first mirror 101 and the second mirror 102 are a concave-convex mirror pair, the second mirror 102 and the third mirror 103 are a concave-convex mirror pair, the third mirror 103 and the fourth mirror 104 are a concave-convex mirror pair, the fourth mirror 104 and the fifth mirror 105 are a concave-convex mirror pair, and the fifth mirror 105 and the sixth mirror 106 are a concave-convex mirror pair. Figure 1As shown, the resonant cavity includes a first concave-convex mirror pair composed of a first concave-convex mirror 1 and a second concave-convex mirror 2, a second concave-convex mirror pair composed of a third concave-convex mirror 4 and a fourth concave-convex mirror 5, and an output coupling mirror 3 and a plane mirror 6 arranged between the first concave-convex mirror pair and the second concave-convex mirror pair, the plane mirror 6 can appropriately elongate the space of the resonant cavity. The output coupling mirror 3 is coated with a transmission film having a preset transmission rate for the oscillation light. The inner surface of the plane mirror 6 is coated with a high reflection film for the oscillation laser. A first titanium sapphire crystal L1 is arranged at the minimum waist between the first concave-convex mirror pair, and a first pump source P1 and a first coupling lens group C1 of the first titanium sapphire crystal L1 are arranged outside the first concave-convex mirror 1, and a residual pump injection component 7 of the first titanium sapphire crystal L1 is arranged outside the second concave-convex mirror 2. A second titanium sapphire crystal L2 is arranged at the minimum waist between the second concave-convex mirror pair, and a second pump source P2 and a second coupling lens group C2 of the second titanium sapphire crystal L2 are arranged outside the third concave-convex mirror 4, and a residual pump injection component 8 of the second titanium sapphire crystal L2 is arranged outside the fourth concave-convex mirror 5. The residual pump injection component can reflect and refocus the residual pump light after a single pass through the titanium sapphire crystal, realize the second efficient absorption of the pump light, further improve the conversion efficiency, and increase the output power of the laser.

[0047] A broadband optical isolator 9 is arranged on the light path (with a large waist) between the first concave-convex mirror 1 and the plane mirror 6, the broadband optical isolator 9 is composed of a magnetic rotation crystal and a natural rotation crystal with an external magnetic field, and both are arranged at the Brewster incident angle, to realize the tunable laser one-way operation. A tuning element 10 is arranged on the light path (with a large waist) between the second concave-convex mirror 2 and the output coupling mirror 3, the tuning element 10 is made of three pieces of quartz crystal material with parallel optical axes and thickness ratios of 1:4:16, and is arranged in the resonant cavity at the Brewster angle, to realize the wide-range tuning of the output laser. A frequency selection element 11 is arranged on the light path (with a large waist) between the third concave-convex mirror 4 and the output coupling mirror 3, the frequency selection element 11 is made of 0.5mm thick fused quartz, to realize the stable single-frequency operation of the laser.

[0048] As an example, Figure 1The maximum output power of the two pump sources (double-end pump source) is 18.5W. After the double-end pump light is shaped and focused by the telescope system, it is focused to the center of the two titanium sapphire crystals, and a focused waist spot with a radius of 27μm is formed at the center of the two titanium sapphire crystals. The first meniscus mirror 1 and the third meniscus mirror 4 are meniscus mirrors with a curvature radius R=100mm, coated with a wideband high-reflection film of 740-890nm and a high-transmission film of 532nm; the coupling-out mirror 3 and the plane mirror 6 are plane-concave mirrors with a curvature radius R=100mm, coated with a wideband high-reflection film of 740-890nm; the second meniscus mirror 2 is a plane mirror coated with a wideband high-reflection film of 740-890nm, and is bonded to a piezoelectric ceramic for fine adjustment of the cavity length of the laser resonator; the fourth meniscus mirror 5 is a wideband output mirror with a transmittance T=5.5% @680-1030nm. The size of the two titanium sapphire crystals is φ4mm×20mm, and both the front and rear end faces are cut at the Brewster angle θ=60.4°. The crystals are immersed in a copper furnace, and the working temperature is controlled to be 17.5℃ by using cooling circulating water. At the center of the titanium sapphire crystal, the waist spot radius of the oscillation light in the meridian plane is 37.3μm, and the waist spot radius in the sagittal plane is 39.3μm. In order to realize stable one-way operation of the laser, an optical one-way device 9 composed of a magnetic rotatory crystal and a quartz rotatory compensation plate is inserted into the optical resonator, wherein the size of the magnetic rotatory crystal is φ4mm×1.8mm, and the thickness of the quartz rotatory compensation plate is 0.342mm. A birefringent filter set with thicknesses of 0.5mm, 2mm and 8mm is selected to realize wide-range tuning of the output wavelength of the laser. At the same time, a standard device with a thickness of 0.5mm, a diameter of 10mm and a surface coated with a 20% reflective film is used for fine frequency selection, so that the laser can stably operate in single frequency.

[0049] Figure 2 The beam transmission characteristics in the resonator of the above-mentioned double-end-pumped double-titanium-sapphire-crystal are shown, and the focused waist spot of the two titanium sapphire crystals is 37μm.

[0050] Figure 3 The output power curve of the high-power continuous-wave single-frequency tunable titanium sapphire laser under different pump powers is shown, and it can be seen that the threshold is 7.56W, the output power is 10.44W when the maximum injection power is 36.75W, and the slope efficiency is as high as 36.62%.

[0051] Figure 4 The wavelength tuning curve obtained by rotating the tuning element is shown, and it can be seen that the laser can realize tuning from 730.12nm to 850.07nm, with a tuning range of 119.95nm. The long-term power stability and longitudinal mode structure of the titanium sapphire laser are also monitored, and the results are shown in Figure 5 It can be seen that the laser stably operates in single frequency, and the power stability is better than ±0.85% for 3 hours.

[0052] Figure 6 An example of an eight-mirror annular cavity in this embodiment is shown. For example... Figure 6 As shown, the resonant cavity includes a first concave-convex mirror pair consisting of a first concave-convex mirror 21 and a second concave-convex mirror 22, a second concave-convex mirror pair consisting of a third concave-convex mirror 24 and a fourth concave-convex mirror 25, a third concave-convex mirror pair consisting of a fifth concave-convex mirror 26 and a sixth concave-convex mirror 27, an output coupling mirror 23, and a plane reflector 28. The first titanium-sapphire crystal L... 21 The first concave-convex mirror 21 is located at the minimum waist spot between the first concave-convex mirror pairs, and a first titanium-sapphire crystal L is provided on the outer side of the first concave-convex mirror 21. 21 pump source P 21 and the first coupling lens group C 21 The outer side of the second concave-convex mirror 22 is provided with a first titanium-sapphire crystal L. 21 The remaining pump reinjection component 12. Second titanium-sapphire crystal L 22 The third concave-convex mirror 24 has a second titanium-sapphire crystal L located at the minimum waist spot between the second pair of concave and convex mirrors. 22 pump source P 22 Second coupling lens group C 22 The outer side of the fourth concave-convex mirror 25 is provided with a second titanium-sapphire crystal L. 22 The remaining pump reinjection component 13. Third titanium-sapphire crystal L 23 The third titanium-sapphire crystal L is located at the minimum waist spot between the third pair of concave and convex mirrors. 23 pump source P 23 and the third coupling lens group C 23 The outer side of the fifth concave-convex mirror 26 is provided with a third titanium-sapphire crystal L. 23 The remaining pump reinjection component 14.

[0053] A broadband optical one-way device 29 is provided on the optical path (with a large waist spot) between the first concave-convex mirror 21 and the plane mirror 28. A tuning element 210 is provided on the optical path (with a large waist spot) between the second concave-convex mirror 22 and the output coupling mirror 23. A frequency selection element 211 is provided on the optical path (with a large waist spot) between the third concave-convex mirror 24 and the output coupling mirror 23.

[0054] Example 2

[0055] As another embodiment, the figure-eight annular cavity includes at least one pair of concave and convex mirrors adjacent to each other in the optical path, two titanium sapphire crystals are disposed between the at least one pair of concave and convex mirrors, a pump source is disposed on the outer side of each of the two concave and convex mirrors, and two residual pump reinjection components are disposed between the two titanium sapphire crystals.

[0056] Figure 7 An example of this embodiment is shown. For example...Figure 7 As shown, the resonant cavity includes a first concave-convex mirror pair consisting of a first concave-convex mirror 31 and a second concave-convex mirror 32, a second concave-convex mirror pair consisting of a third concave-convex mirror 34 and a fourth concave-convex mirror 35, and an output coupling mirror 33 and a plane reflector 36 disposed between the first concave-convex mirror pair and the second concave-convex mirror pair. A first titanium-sapphire crystal L is respectively disposed at two waist spots between the first concave-convex mirror pairs. 31 Second Titanium Sapphire Crystal L 32 The outer side of the first concave-convex mirror 31 is provided with a first titanium-sapphire crystal L. 31 pump source P 31 and the first coupling lens group C 31 The outer side of the second concave-convex mirror 32 is provided with a second titanium-sapphire crystal L. 32 pump source P 32 and the first coupling lens group C 32 The first titanium sapphire crystal L 31 With the second titanium sapphire crystal L 32 Two beam-changing lenses F are installed between them. 31 and F 32 The beam-shifting lens, acting as a residual pump re-injection component, focuses the remaining pump back to the Ti:sapphire crystal at the rear end for secondary absorption. This allows for an additional pump source to be placed on the outer side of the concave-convex mirror pair, further increasing the output power of the Ti:sapphire laser. Similarly, a third Ti:sapphire crystal L is placed at each of the two waist spots between the second concave-convex mirror pair. 33 And the fourth titanium sapphire crystal L 34 The outer side of the third concave-convex mirror 34 is provided with a third titanium-sapphire crystal L. 33 pump source P 33 and the third coupling lens group C 33 The outer side of the fourth concave-convex mirror 35 is provided with a fourth titanium-sapphire crystal L. 34 pump source P 34 and the fourth coupling lens group C 34 Third Titanium Sapphire Crystal L 33 With the fourth titanium sapphire crystal L 34 Two beam-changing lenses F are installed between them. 33 and F 34 A broadband optical one-way device 39 is provided on the optical path (with a large waist spot) between the first concave-convex mirror 31 and the plane mirror 36. A tuning element 310 is provided on the optical path (with a large waist spot) between the second concave-convex mirror 32 and the output coupling mirror 33. A frequency selection element 311 is provided on the optical path (with a large waist spot) between the third concave-convex mirror 34 and the output coupling mirror 33.

[0057] As another embodiment, in the octagonal ring cavity, two titanium sapphire crystals are arranged between at least one concave-convex mirror pair, and at the same time, one titanium sapphire crystal is arranged between at least one concave-convex mirror pair, and the outer sides of the concave-convex mirrors on both sides of the titanium sapphire crystal are respectively provided with corresponding pump sources and residual pump injection components. Figure 8 An example is shown, in which the resonant cavity includes a first concave-convex mirror pair composed of a first concave-convex mirror 41 and a second concave-convex mirror 42, a second concave-convex mirror pair composed of a third concave-convex mirror 44 and a fourth concave-convex mirror 45, a third concave-convex mirror pair composed of a fifth concave-convex mirror 46 and a sixth concave-convex mirror 47, and an output coupling mirror 43 and a plane mirror 48.

[0058] Two waist spots between the first concave-convex mirror pair are respectively provided with a first titanium sapphire crystal L 41 and a second titanium sapphire crystal L 42 , the outer side of the first concave-convex mirror 41 is provided with a pump source P 41 and a first coupling lens group C 41 of the first titanium sapphire crystal L 41 , the outer side of the second concave-convex mirror 42 is provided with a pump source P 42 and a first coupling lens group C 42 of the second titanium sapphire crystal L 42 . Two beam transformation lenses F 41 and F 42 are arranged between the first titanium sapphire crystal L 41 and the second titanium sapphire crystal L 42 , which are used as residual pump injection components to re-converge the residual pump to the titanium sapphire crystal at the rear end for secondary absorption, so that one more pump source can be arranged in the opposite direction, further improving the output power of the titanium sapphire laser. Similarly, two waist spots between the second concave-convex mirror pair are respectively provided with a third titanium sapphire crystal L 43 and a fourth titanium sapphire crystal L 44 , the outer side of the third concave-convex mirror 44 is provided with a pump source P 43 and a third coupling lens group C 43 of the third titanium sapphire crystal L 43 , the outer side of the fourth concave-convex mirror 45 is provided with a pump source P 44 and a fourth coupling lens group C 44 of the fourth titanium sapphire crystal L 44 . Two beam transformation lenses F 43 and F 44 are arranged between the third titanium sapphire crystal L 43 and the fourth titanium sapphire crystal L 44 . A fifth titanium sapphire crystal L 45 is arranged at the minimum waist spot between the third concave-convex mirror pair, and a pump source P 45 of the fifth titanium sapphire crystal L 25and the fifth coupling lens group C 45， The outer side of the fifth concave-convex mirror 46 is provided with a fifth titanium-sapphire crystal L. 45 The remaining pump reinjection component 12.

[0059] A broadband optical one-way device 49 is provided on the optical path (with a large waist spot) between the first concave-convex mirror 41 and the plane mirror 48. A tuning element 410 is provided on the optical path (with a large waist spot) between the second concave-convex mirror 42 and the output coupling mirror 43. A frequency selection element 411 is provided on the optical path (with a large waist spot) between the third concave-convex mirror 44 and the output coupling mirror 43.

[0060] The multi-pumped, multi-TiSapphire crystal resonant cavity structure of this application not only overcomes the limitation of pump source output power on TiSapphire laser output power, but also effectively avoids the impact of thermal effects of a single TiSapphire crystal under high pump power on the stable operating region of the TiSapphire laser, as well as laser damage caused by crystal damage under high-power pumping. Furthermore, this application employs a stacked figure-eight ring resonant cavity composed of multiple concave and convex mirror pairs to create multiple small waist spot positions for placing the TiSapphire crystal, satisfying the conditions of short upper level lifetime and high pump rate required by the TiSapphire crystal, thus significantly improving the output power of the TiSapphire laser.

[0061] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A high-power continuous-wave single-frequency tunable Ti:sapphire laser, characterized in that, Includes a resonant cavity and at least two titanium sapphire crystals; The resonant cavity is a figure-eight shaped ring cavity. The resonant cavity includes an output coupling mirror and a pair of concave and convex mirrors adjacent to each other in the optical path, the same number as the titanium sapphire crystals. The titanium sapphire crystals are disposed at the waist spot between the two concave and convex mirrors of the corresponding pair of concave and convex mirrors. Each Ti:Sapphire crystal has an independent pump source and an independent residual pump reinjection component; in each concave-convex mirror pair, the pump source is located on the outer side of the first concave-convex mirror and the residual pump reinjection component is located on the outer side of the second concave-convex mirror. The remaining pump re-injection component is a combination of a plano-convex lens with a preset focal length and a 0-degree reflector or a concave reflector with a preset curvature; the remaining pump re-injection component reflects and refocuses the pump light remaining after it passes through the titanium sapphire crystal once, so as to achieve secondary efficient absorption of the pump light.

2. The high-power continuous-wave single-frequency tunable Ti:sapphire laser according to claim 1, characterized in that, The pump source is an all-solid-state continuous wave single-frequency 532nm laser.

3. The high-power continuous-wave single-frequency tunable Ti:sapphire laser according to claim 1, characterized in that, The laser output from the pump source matches the gain absorption spectrum of the titanium sapphire crystal.

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