CN211981132U - Electro-optical Q-switched cavity emptying laser - Google Patents

Electro-optical Q-switched cavity emptying laser Download PDF

Info

Publication number
CN211981132U
CN211981132U CN202020828176.7U CN202020828176U CN211981132U CN 211981132 U CN211981132 U CN 211981132U CN 202020828176 U CN202020828176 U CN 202020828176U CN 211981132 U CN211981132 U CN 211981132U
Authority
CN
China
Prior art keywords
laser
electro
crystal
optical
mirror
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202020828176.7U
Other languages
Chinese (zh)
Inventor
廖文斌
张戈
李丙轩
林长浪
黄凌雄
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujian Institute of Research on the Structure of Matter of CAS
Original Assignee
Fujian Institute of Research on the Structure of Matter of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujian Institute of Research on the Structure of Matter of CAS filed Critical Fujian Institute of Research on the Structure of Matter of CAS
Priority to CN202020828176.7U priority Critical patent/CN211981132U/en
Application granted granted Critical
Publication of CN211981132U publication Critical patent/CN211981132U/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Lasers (AREA)

Abstract

The utility model discloses an electro-optical Q chamber empting laser, including laser unit and the transmission reflection unit, laser crystal, folding mirror, electro-optical Q device and the full reflection mirror that set gradually in laser unit light-emitting side, the position that sets up of folding mirror satisfies first condition, and first condition is:
Figure DDA0002496803820000011
wherein L is the distance between the folding mirror and the transmission reflection unit, R is the curvature radius of the folding mirror, and f is the thermal focus of the laser crystal; the folding mirror is a concave lens, and the concave surface of the concave lens is used for foldingThe laser light emitted from the laser crystal is reflected to the electro-optical Q-switching device, and the laser light reflected from the all-mirror is reflected to the laser crystal. This application uses concave lens as folding mirror to place it in apart from laser pumping mirror distance L department, make the laser radius behind the folding mirror unchangeable, improved the stability of the operation of the Q crystal is transferred to the lightning, further promoted the operation stability of cavity emptying laser.

Description

Electro-optical Q-switched cavity emptying laser
Technical Field
The application relates to an electro-optical Q-switched cavity emptying laser, and belongs to the technical field of lasers.
Background
The electro-optic Q-switched cavity emptying technology is an important means for realizing the output of laser pulses with high repetition frequency, narrow pulse width and high peak power. The working principle of the laser (electro-optic Q-switching cavity dumping laser) of the electro-optic Q-switching cavity dumping technology is as follows: laser oscillation is established in a resonant cavity of which the front cavity mirror and the rear cavity mirror are all full-reflection mirrors, and at the moment, an electro-optical device in the cavity is controlled by a high-voltage electric pulse with high speed and high repetition frequency to quickly radiate and output all laser energy in the cavity to the outside of the cavity, so that a laser pulse with the narrowest pulse width of 2L/c (L is the cavity length; light speed in the resonant cavity).
In a solid laser, the thermal lens effect of a laser crystal can severely affect the output power and the light speed quality of the laser, and particularly, the thermal lens effect of the laser crystal has more serious influence on a cavity emptying laser with high intra-cavity power density. Therefore, in the design process of the cavity of the laser structure, the laser radius of key elements (the electro-optic Q-switched crystal, the polarizer and the quarter-wave plate) in the cavity-emptying resonant cavity has low sensitivity to the thermal focal length change of the laser crystal, so that the laser can stably work under the condition of pump power fluctuation. In addition, stable cavity-dumping lasers have additional requirements for the most core element electro-optic Q-switched crystal. Electro-optic Q-switched crystal is by two masses the same, and the size is equal, and the direction becomes 90 crystals each other and constitutes, and in order to guarantee that electro-optic crystal operation is good, need guarantee that the laser radius through two crystals is unanimous, and too big laser radius changes, can make the phase compensation of two crystals destroyed to cause the operation of cavity emptying laser instrument unstable, especially influence more seriously to high heavy frequency laser instrument.
At present, various cavity emptying lasers are realized in China, such as cavity emptying lasers disclosed by a document '914 nmLD pumping high-efficiency cavity emptying electro-optic Q-switched laser' and a '500 kHz,6ns high repetition frequency electro-optic cavity emptying Nd: YVO4 laser', and the like, and the cavity emptying lasers only optimize the influence of the thermal effect of the crystal on the laser and ignore the influence of the laser radius change on the electro-optic crystal on the laser performance.
SUMMERY OF THE UTILITY MODEL
An object of the application is to provide an electro-optical Q-switched cavity dumping laser to solve the technical problem that laser operation is unstable due to laser radius change of the existing cavity dumping laser.
The utility model discloses an electro-optical Q-switched cavity emptying laser, which comprises a laser unit, a transmission reflection unit, a laser crystal, a folding mirror, an electro-optical Q-switched device and a total reflection mirror, wherein the transmission reflection unit, the laser crystal, the folding mirror, the electro-optical Q-switched device and the total reflection mirror are sequentially arranged at the light-emitting side of the laser unit;
the laser unit is used for providing pump light for the laser crystal;
the transmission and reflection unit is used for transmitting the pump light emitted by the laser unit and reflecting the laser light emitted by the laser crystal;
the laser crystal converts the pump light transmitted by the transmission and reflection unit into laser and enhances the intensity of the laser incident to the laser crystal;
the setting position of the folding mirror meets a first condition, and the first condition is as follows:
Figure BDA0002496803800000021
wherein L is the distance between the folding mirror and the transmission reflection unit, R is the curvature radius of the folding mirror, and f is the thermal focal length of the laser crystal;
the folding mirror is a concave lens, and the concave surface of the concave lens is used for reflecting laser light emitted from the laser crystal to the electro-optical Q-switching device and reflecting laser light reflected from the full reflector to the laser crystal;
the electro-optical Q-switching device is used for controlling the polarization direction of laser passing through the electro-optical Q-switching device;
the total reflection mirror is used for reflecting the laser light emitted from the electro-optic Q-switching device close to the side of the total reflection mirror to the electro-optic Q-switching device again.
Preferably, the area, which is 0-5 mm away from the central axis of the concave lens, on the concave surface of the folding mirror is a laser reflecting surface.
Preferably, L is
Figure BDA0002496803800000022
Wherein R is the radius of curvature of the fold mirror.
Preferably, the value range of R is more than or equal to 50mm and less than or equal to 1000 mm;
preferably, the transflective unit is a pump mirror.
Preferably, the transmission and reflection unit is a laser film, and the laser film is arranged on the end face of the laser crystal close to the laser unit.
Preferably, the laser unit includes a pump light source and a coupling lens group;
the pump light emitted by the pump light source is incident to the coupling lens group;
the coupling lens group is used for adjusting the radius of laser incident to the laser crystal;
preferably, the coupling lens group comprises two convex lenses which are coaxial and have opposite convex surfaces; the two convex lenses are preferably plano-convex lenses including a first plano-convex lens and a second plano-convex lens. Wherein the first plano-convex lens is placed at a distance f from the pump source1F of1Is the focal length of the first plano-convex lens.
Preferably, the electro-optical Q-switched device comprises a polarizing element, a quarter-wave plate and an electro-optical Q-switched crystal which are arranged in sequence;
the polarizing element is used for polarizing the laser passing through the polarizing element to form S polarized light;
the quarter-wave plate is used for adjusting the polarization direction of the laser passing through the quarter-wave plate;
the electro-optical Q-switching crystal is used for controlling the conversion between S polarized light and P polarized light of laser which is reflected by the full reflector and passes through the full reflector and the quarter wave plate, so that the laser is emitted from the polarizing element after oscillating between the transmission reflection unit and the full reflector.
Preferably, the polarizing element comprises at least one polarizer, and the main axis direction of each polarizer is at brewster angle with the laser incident on the polarizer.
Preferably, the direction of the main axis of the quarter-wave plate is 45 degrees to the polarization direction of the laser incident thereon, and the direction of the main axis of the electro-optical Q-switching crystal is 45 degrees to the polarization direction of the laser incident thereon.
The utility model discloses an electro-optical Q-switched cavity emptying laser compares in prior art, has following beneficial effect:
the utility model discloses an electro-optical Q-switched cavity emptying laser uses concave lens as folding mirror to place it in apart from laser pumping mirror distance L department, laser radius's change after can gently folding mirror effectively, make the laser radius behind the folding mirror unchangeable, make through cavity emptying laser core element-electro-optical Q-switched crystal's laser radius change is minimum, have the advantage of the low sensitivity of laser radius change, improved the stability of electro-optical Q-switched crystal operation, thereby further promoted the operation stability of cavity emptying laser, simultaneously, the utility model discloses an electro-optical Q-switched cavity emptying laser's simple structure has very big using value.
Drawings
Fig. 1 is a schematic structural diagram of an electro-optic Q-switched cavity dumping laser according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an electro-optic Q-switched crystal according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of the polarization and transmission path of the laser in the resonant cavity when no voltage is applied to the electro-optic Q-switch crystal according to the embodiment of the present invention;
FIG. 4 is a schematic diagram of the polarization and transmission path of the laser in the resonant cavity when the electro-optic Q-switch crystal of the embodiment of the present invention applies a quarter-wave voltage;
FIG. 5 is a graph showing the laser radius distribution at each point in the resonant cavity in an embodiment of the present invention;
fig. 6 is a laser pulse sequence diagram according to an embodiment of the present invention;
fig. 7 is a graph of the average power of the laser output over time according to an embodiment of the present invention;
fig. 8 is a diagram illustrating a laser radius distribution in the cavity when the curvature radius R of the folding mirror is 200mm according to an embodiment of the present invention;
fig. 9 is a graph showing the laser radius distribution in the cavity when the curvature radius R of the folding mirror is 400mm in the embodiment of the present invention.
List of parts and reference numerals:
1. a pump light source; 2. a first plano-convex lens; 3. a second plano-convex lens; 4. a pump mirror; 5. a laser crystal; 6. a folding mirror; 7. a first polarizing plate; 8. a second polarizing plate; 9. a quarter wave plate; 10. an electro-optic Q-switched crystal; 11. a total reflection mirror.
Detailed Description
The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples.
Fig. 1 is a schematic structural view of an electro-optical Q-switched cavity emptying laser according to an embodiment of the present invention.
The electro-optical Q-switched cavity emptying laser provided by the embodiment of the utility model comprises a laser unit, a transmission reflection unit, a laser crystal 5, a folding mirror 6, an electro-optical Q-switched device 10 and a total reflection mirror 11, wherein the transmission reflection unit, the laser crystal 5, the folding mirror 6, the electro-optical Q-switched device and the total reflection mirror are sequentially arranged on the light-emitting side of the laser unit; the portion between the transflective unit and the total reflection mirror 11 is a laser resonator.
Wherein the laser unit is used for providing pump light for the laser crystal 5; in this embodiment, the laser unit includes a pump light source 1 and a coupling lens group; the pump light emitted by the pump light source 1 is incident to the coupling lens group; a coupling lens group for adjusting the radius of the laser light incident to the laser crystal 5; the pumping light source 1 is a laser diode end pumping source of pulses with continuously adjustable output power or adjustable pulse width and frequency; the coupling lens group comprises two convex lenses which are coaxial and have opposite convex surfaces. In this embodiment, the coupling lens group includes a first plano-convex lens 2 and a second plano-convex lens 3, wherein the first plano-convex lensIs placed at a distance f from the pump source1F of1Is the focal length of the first plano-convex lens. The pump light emitted by the pump light source 1 is a divergent light, and when the divergent light is located at the focus of the first plano-convex lens 2, the divergent pump light is collimated into parallel light after passing through the first plano-convex lens 2, and the parallel light is focused into a circular light spot after passing through the second plano-convex lens 3 and irradiates on the laser crystal 5. The specific relationship is as follows:
Figure BDA0002496803800000051
wherein phi is2Is the diameter of the light spot on the laser crystal 51Is the spot diameter of the emitting end of the pump light source 1, f1Is the focal length of the first plano-convex lens 2; f. of2Is the focal length of the second plano-convex lens 3. Therefore, the diameter of the pump light injected into the laser crystal 5 can be changed by adjusting the focal lengths of the first plano-convex lens 2 and the second plano-convex lens 3, so that the mode matching of a pump light spot and a resonant cavity mode is realized, and the overall operating efficiency of the laser is improved.
The transmission and reflection unit in the present application is used for transmitting the pump light emitted from the laser unit and reflecting the laser light emitted from the laser crystal 5; in the embodiment of the present application, the transflective unit may adopt two structures, wherein one of the two structures is to use the existing pump mirror 4 as the transflective unit; the other structure is that a laser film is arranged on the end face of the laser crystal 5 close to the laser unit, and the laser film is used as a transmission reflection unit. The laser film comprises a film with high transmittance (transmittance can reach more than 98%) for the pump light and a film with high reflection for the laser light, so that the high transmittance and the high reflection for the pump light are realized. This embodiment adopts when setting up the laser film in the structure on laser crystal 5 is close to the terminal surface of laser unit, has reduced optical device for laser instrument inner structure is compact, has reduced the volume of this application cavity emptying laser instrument.
The laser crystal 5 in the present application converts the pump light transmitted by the transmission and reflection unit into laser light, and enhances the intensity of the laser light incident on the laser crystal; the laser crystal 5 is the power core part of the cavity emptying laser in the application.
The setting position of the folding mirror 6 in the present application satisfies a first condition, which is:
Figure BDA0002496803800000052
wherein, L is the distance between the folding mirror 6 and the transmission reflection unit, R is the curvature radius of the folding mirror 6, and f is the thermal focus of the laser crystal 5; the folding mirror 6 is a concave lens, and the concave surface of the concave lens is used for reflecting the laser emitted from the laser crystal 5 to the electro-optical Q-switching device and reflecting the laser reflected from the total reflection mirror 11 to the laser crystal 5; through the arrangement, the radius of the laser reflected by the folding mirror 6 can be unchanged, and the radius of the laser passing through the laser Q-switched crystal is ensured to be unchanged. Wherein the folding mirror 6 can be a plano-concave lens or a biconcave lens.
The electro-optical Q-switching device is used for controlling the polarization direction of laser passing through the electro-optical Q-switching device, so that the laser is output after oscillating between the transmission reflection unit and the total reflection mirror; wherein the laser light incident to the electro-optical Q-switching device is laser light of a constant radius.
The hologram 11 of the present application is used to reflect laser light emitted from the electro-optical Q-switching device near the hologram side to the electro-optical Q-switching device again.
In order to enable the radius of the laser emitted from the folding mirror 6 to be more stable and unchanged, the area, which is 0-5 mm away from the central axis of the concave lens, on the concave surface is defined as a laser reflecting surface, and the laser is limited to be reflected only in the laser reflecting surface.
Further, L takes the value of
Figure BDA0002496803800000061
Where R is the radius of curvature of the fold mirror 6. The larger the R value is, the better the radial stability of the laser light emitted from the folding mirror 6 is. The value range of R is limited to be more than or equal to 50mm and less than or equal to 1000 mm;
the electro-optical Q-switching device comprises a polarizing element, a quarter-wave plate 9 and an electro-optical Q-switching crystal 10 which are sequentially arranged;
the polarizing element is used for polarizing the laser passing through the polarizing element to form S polarized light; the polarizing element comprises at least one polarizer arranged on a laser transmission path, and the main axis direction of each polarizer forms a Brewster angle with laser incident to the polarizer. Two polarizers are provided in this embodiment: a first polarizer 7 and a second polarizer 8, both of which are thin film polarizers.
The quarter-wave plate 9 is used for adjusting the polarization direction of laser passing through the quarter-wave plate, wherein the main axis direction of the quarter-wave plate and the polarization direction of laser incident on the quarter-wave plate form a 45-degree angle, and conversion between circularly polarized light and S polarized light and P polarized light can be realized only if the angle is met;
the utility model provides an electro-optical Q-switched crystal 10 for control is through full reflection of mirror reflection and through its and the conversion between S polarized light and P polarized light of the laser of quarter-wave plate, make laser follow polarization component after the oscillation between transmission reflecting element and full reflection of mirror 11 emergent, wherein electro-optical Q-switched crystal 10' S main axis direction is 45 with the polarization direction of the laser of incidenting on it, only satisfy this angle, can realize the conversion between circular polarized light and the P polarized light, electro-optical Q-switched crystal 10 can be: RTP, KTP, BBO, LBO, LGS, LiNbO3One kind of (1).
The application uses the above embodiments to explain the working principle of the electro-optic Q-switched cavity emptying laser as follows:
the pump light output by the pump light source 1 is shaped by the coupling lens group and then enters the laser crystal 5 through the pump mirror 4.
The electro-optic Q-switch crystal 10 pressurization process is shown in figure 2.
When no voltage is applied to the electro-optically Q-switched crystal 10, the polarization and transmission of the laser light in the resonant cavity are as shown in fig. 3, and the laser light in the cavity is reflected by the folding mirror 6 and then passes through the first polarizing plate 7 and the second polarizing plate 8, and the polarization direction is the S direction (vertical direction). After the S polarized light passes through the quarter-wave plate 9 with the principal axis direction forming 45 degrees with the polarization direction of the laser incident to the quarter-wave plate 9, the polarization direction is changed from the S direction to circular polarization, then the circular polarized laser passes through the electro-optic Q-switched crystal 10, is finally reflected by the full-mirror 11, and passes through the electro-optic Q-switched crystal 10 again, in the process, the polarization direction of the laser in the cavity is kept unchanged as circular polarization, and then passes through the quarter-wave plate 9, at the moment, the polarization direction of the laser is changed from the circular polarization direction to the P direction (horizontal direction), and when the laser passes through the second polarizer 8 placed at the brewster angle, the laser is completely transmitted out of the resonant cavity to form laser output. At this time, the coupling output ratio of the laser is 100%, the cavity loss is the largest, laser oscillation cannot be formed in the cavity, and the population inversion of the laser crystal 5 is abruptly increased.
When a quarter-wave voltage is applied to the electro-optically Q-switched crystal 10, the electro-optically Q-switched crystal 10 may be considered a quarter-wave plate. As shown in fig. 4, the S-polarized light reflected by the polarizer passes through the quarter-wave plate and the electro-optical Q-switched crystal 10 twice, the polarization direction of the S-polarized light remains unchanged, and the laser light is reflected back to the original optical path by the polarizer, thereby forming laser oscillation. At this time, the coupling output ratio of the laser is 0, the cavity loss is minimized, and the laser crystal 5 is inverted to reduce the population to be converted into oscillation laser light in the laser cavity.
After a certain laser oscillation time (the pressurization time of the electro-optically Q-switched crystal 10), the voltage applied to the electro-optically Q-switched crystal 10 is removed, and at this time, the laser energy stored in the cavity is transmitted by the polaroid by 100% and output to form pulse laser.
In the laser resonant cavity with the structure, the laser radius distribution can be obtained by the ABCD law and the self-reproduction mode theory of the cavity.
The resonant cavity from the pump mirror 4 to the total reflection mirror 11, and then from the total reflection mirror 11 to the pump mirror 4, the ABCD matrix of the resonant cavity is:
Figure BDA0002496803800000081
wherein:
Figure BDA0002496803800000082
is the transmission matrix of the pump mirror 4;
Figure BDA0002496803800000083
is a transmission matrix between the pump mirror 4 and the laser crystal 5, l1 is a distance between the pump mirror 4 and the laser crystal 5, and n is a transmission medium refractive index;
Figure BDA0002496803800000084
is a transmission matrix of the thermal focus of the laser crystal 5, and f is the thermal focus of the laser crystal 5 under certain pumping power;
Figure BDA0002496803800000085
is the transmission matrix of the laser crystal 5, lc is the length of the laser crystal 5, ncIs the refractive index of the laser crystal 5;
Figure BDA0002496803800000086
is a transmission matrix between the laser crystal 5 and the folding mirror 6, l2 is the distance between the laser crystal 5 and the folding mirror 6, and n is the refractive index of a transmission medium;
Figure BDA0002496803800000087
is the transmission matrix of the folding mirror 6, and R is the curvature radius of the folding mirror 6;
Figure BDA0002496803800000088
a transmission matrix between the folding mirror 6 and the electro-optically Q-switched crystal 10 is shown, l3 is the distance between the folding mirror 6 and the electro-optically Q-switched crystal 10, and n is the refractive index of a transmission medium;
Figure BDA0002496803800000091
is a transmission matrix of the electro-optically Q-switched crystal 10, le is the length of a single crystal of the electro-optically Q-switched crystal 10, neIs the refractive index of the electro-optically Q-switched crystal 10, and l delta is the distance between two crystals in the electro-optically Q-switched crystal 10;
Figure BDA0002496803800000092
a transmission matrix between the electro-optically Q-switched crystal 10 and the total reflection mirror 11, l4 is the distance between the electro-optically Q-switched crystal 10 and the total reflection mirror 11, and n is the refractive index of a transmission medium;
Figure BDA0002496803800000093
a transmission matrix being the perfect mirror 11;
the ABCD value of the resonant cavity is obtained, and the laser radius on the pump mirror 4 can be obtained by the cavity mode self-reproduction theory:
Figure BDA0002496803800000094
by the laser radius omega on the pump mirror 4zAnd laser radius of curvature RzThe laser radius distribution in the whole resonant cavity can be obtained.
The electro-optically tuned Q-cavity dumping laser of the present application will be described below with reference to specific embodiments, the laser radius in the cavity.
This embodiment further introduces in detail with 1.5um high frequency cavity emptying laser the technical scheme of the utility model. Of course, the utility model discloses a cavity emptying laser also can be for the cavity emptying laser of all kinds of wavelengths such as 1.0um, 2.0um, various frequencies.
In the present example, a 976nm semiconductor laser pumping Er: Yb: YAB laser crystal 5, while modulated using electro-optical Q-switched crystal 10(RTP), achieves laser outputs of 100kHz, 3.3ns, 1531 nm. The equipment parameters in the examples are as follows:
the pump light source 1 is a semiconductor laser with a central wavelength of 976nm and a core diameter of 100um, and its output pump power is 27W in this example.
The coupling lens groups are all plano-convex lenses with the focal length of 50 mm.
The laser crystal 5 is a crystal of Er, Yb, YAB with refractive index n of 3 x 1.5mm (lc 1.5mm)cIs 1.75, and has a thermal focal length f of 15mm under a pump power of 27W. The front end surface is plated with 976nm high-transmittance and 1500-plus 1600nm total reflectionThe film was used as a pump mirror 4 (l1 ═ 0), and at the same time, the back end face was coated with 1500-.
The folding mirror 6 is a plano-concave lens with a curvature radius R of 100mm, and is 50mm away from the front end face l2 of the laser crystal 5.
The electro-optical Q-switched crystal 10 consists of two RTP crystals of the same size (4 x 10mm), the refractive index n of the crystal being such thate1.76, and the distance/. DELTA.between the two crystals was 5 mm. The distance l3 between the electro-optical Q-switching crystal 10 and the fold mirror 6 is 200 mm.
The total reflection mirror 11 is coated with a 1500-1600nm total reflection film, and the distance l3 between the total reflection film and the electro-optical Q-switched crystal 10 is 75 mm.
In addition, the resonant cavity is built in air, and laser light propagates in a medium in the air, so that n is 1.
Substituting the data into formula (1) can calculate the transmission matrix of the laser resonant cavity
Figure BDA0002496803800000101
The laser radius of each point in the resonant cavity can be calculated by the ABCD value.
Fig. 5 is the calculated laser radius distribution of each point in the resonant cavity, in fig. 5, point a is the rear end face of the laser crystal 5, point B is the reflection face of the folding mirror 6, point C is the front end face of the electro-optically tuned Q crystal 10, point D is the rear end face of the electro-optically tuned Q crystal 10, and point E is the total reflection mirror 11. As can be seen from fig. 5, after the laser light released from the laser crystal 5 in the resonator is reflected by the folding mirror 6, the change in the radius is gradually reduced, and the laser radius between the folding mirror 6 and the total reflection mirror tends to be uniform. The laser radius of the front end face C of the electro-optical Q-switched crystal 10 is 737.238um, the laser radius of the rear end face D of the electro-optical Q-switched crystal 10 is 736.425um, the laser radius variation is 0.813um, and the variation rate is only 0.11%, so that the laser radius passing through the electro-optical Q-switched crystal 10 can be regarded as unchanged. Fig. 6 is a laser pulse sequence chart obtained by experiment, each pulse peak value is almost consistent, and the pulse energy difference is less than 2%; fig. 7 is a fluctuation curve of the average laser output power with time, and it can be seen from the graph that the change rate of the laser output power is 2.3%, and the laser output power has good stability. Fig. 8 and 9 are graphs of the laser radius distribution in the resonant cavity at the respective radii of curvature R of the folding mirror 6 of 200mm and 400 mm. When the curvature radius is 200mm, the variation of laser spots at two positions of the electro-optically Q-switched crystal 10C, D is 0.145um, and the variation rate is 0.011 percent; when the curvature radius is 400mm, the laser facula variation amount of the electro-optically Q-switched crystal 10C, D at two positions is 0.019um, and the variation rate is 0.000726%. It can be known that, when the curvature radius R of the folding mirror 6 is larger, the difference of the laser radius passing through the electro-optical crystal is smaller. The use of a plano-concave lens with a large radius of curvature as the folding mirror 6 is more effective when experimental conditions permit.
The utility model discloses an electro-optical Q-switched cavity emptying laser uses concave lens as folding mirror to place it in apart from laser pumping mirror distance L department, laser radius after can gently folding mirror changes effectively, makes the laser radius behind the folding mirror unchangeable, makes and makes through cavity emptying laser core element-electro-optical Q-switched crystal's laser radius change minimum, has the advantage of laser radius change hyposensitivity, has improved the stability of electro-optical Q-switched crystal operation, thereby has further promoted the operational stability of cavity emptying laser, simultaneously, the utility model discloses an electro-optical Q-switched cavity emptying laser's simple structure has very big using value.
Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims (10)

1. An electro-optical Q-switched cavity emptying laser is characterized by comprising a laser unit, a transmission reflection unit, a laser crystal, a folding mirror, an electro-optical Q-switched device and a total reflection mirror, wherein the transmission reflection unit, the laser crystal, the folding mirror, the electro-optical Q-switched device and the total reflection mirror are sequentially arranged on the light emitting side of the laser unit;
the laser unit is used for providing pump light for the laser crystal;
the transmission and reflection unit is used for transmitting the pump light emitted by the laser unit and reflecting the laser light emitted by the laser crystal;
the laser crystal converts the pump light transmitted by the transmission and reflection unit into laser and enhances the intensity of the laser incident to the laser crystal;
the setting position of the folding mirror meets a first condition, and the first condition is as follows:
Figure FDA0002496803790000011
wherein L is the distance between the folding mirror and the transmission reflection unit, R is the curvature radius of the folding mirror, and f is the thermal focal length of the laser crystal;
the folding mirror is a concave lens, and the concave surface of the concave lens is used for reflecting laser emitted from the laser crystal to the electro-optical Q-switching device and reflecting laser reflected from a full reflector to the laser crystal;
the electro-optical Q-switching device is used for controlling the polarization direction of laser passing through the electro-optical Q-switching device;
the total reflection mirror is used for reflecting the laser light emitted from the electro-optic Q-switching device close to the side of the total reflection mirror to the electro-optic Q-switching device again.
2. The electro-optic Q-switched cavity dumping laser according to claim 1, wherein an area of the concave surface of the folded mirror 0-5 mm away from the central axis of the concave lens is a laser reflecting surface.
3. The electro-optically Q-switched cavity dumping laser of claim 1 wherein L is
Figure FDA0002496803790000012
Wherein R is the radius of curvature of the fold mirror.
4. The electro-optically Q-switched cavity dumping laser of claim 1, wherein R is in the range of 50mm ≦ R ≦ 1000 mm.
5. The electro-optically Q-switched cavity dumping laser of claim 1, wherein said transflective unit is a pump mirror.
6. The electro-optically Q-switched cavity dumping laser of claim 1, wherein said transflective unit is a laser film disposed on an end face of said laser crystal adjacent to said laser unit.
7. The electro-optically Q-switched cavity dumping laser of claim 1, wherein said laser unit comprises a pump light source and a coupling lens group;
the pump light emitted by the pump light source is incident to the coupling lens group;
the coupling lens group is used for adjusting the radius of laser incident to the laser crystal;
the coupling lens group comprises two convex lenses which are coaxial and have opposite convex surfaces.
8. The electro-optical Q-switched cavity dumping laser according to any one of claims 1 to 7, wherein the electro-optical Q-switching device comprises a polarizing element, a quarter-wave plate and an electro-optical Q-switching crystal which are arranged in sequence;
the polarizing element is used for polarizing the laser passing through the polarizing element to form S polarized light;
the quarter-wave plate is used for adjusting the polarization direction of the laser passing through the quarter-wave plate;
the electro-optical Q-switching crystal is used for controlling the conversion between S polarized light and P polarized light of laser which is reflected by the full reflector and passes through the full reflector and the quarter wave plate, so that the laser is emitted from the polarizing element after oscillating between the transmission reflection unit and the full reflector.
9. An electro-optically Q-switched cavity dumping laser according to claim 8, wherein said polarizing element comprises at least one polarizer, each having a principal axis oriented at a Brewster angle with respect to laser light incident thereon.
10. The electro-optically Q-switched cavity dumping laser of claim 8 wherein the major axis of said quarter-wave plate is oriented at 45 ° to the polarization of the laser light incident thereon, and the major axis of said electro-optically Q-switched crystal is oriented at 45 ° to the polarization of the laser light incident thereon.
CN202020828176.7U 2020-05-18 2020-05-18 Electro-optical Q-switched cavity emptying laser Active CN211981132U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202020828176.7U CN211981132U (en) 2020-05-18 2020-05-18 Electro-optical Q-switched cavity emptying laser

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202020828176.7U CN211981132U (en) 2020-05-18 2020-05-18 Electro-optical Q-switched cavity emptying laser

Publications (1)

Publication Number Publication Date
CN211981132U true CN211981132U (en) 2020-11-20

Family

ID=73370849

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202020828176.7U Active CN211981132U (en) 2020-05-18 2020-05-18 Electro-optical Q-switched cavity emptying laser

Country Status (1)

Country Link
CN (1) CN211981132U (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112636155A (en) * 2020-12-28 2021-04-09 北京超快光子科技有限公司 Multi-pulse regenerative amplified laser system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112636155A (en) * 2020-12-28 2021-04-09 北京超快光子科技有限公司 Multi-pulse regenerative amplified laser system

Similar Documents

Publication Publication Date Title
US5991317A (en) Retinal photocoagulator including diode pumped, multi-axial mode intracavity doubled laser
US5638388A (en) Diode pumped, multi axial mode intracavity doubled laser
JP6640733B2 (en) Mid-infrared Kerr-lens mode-locked laser with polycrystalline TM: II-VI material for normal incidence mounting and method for controlling parameters of polycrystalline TM: II-VI kerr-lens mode-locked laser
US6287298B1 (en) Diode pumped, multi axial mode intracavity doubled laser
CN100407519C (en) LD pumping cogain double cavity very-large frequency difference double frequency Nd:YAG laser
WO2010111094A2 (en) Intracavity harmonic generation using a recycled intermediate harmonic
US6931037B2 (en) Diode pumped, multi axial mode intracavity doubled laser
CN216850735U (en) Narrow-linewidth dual-wavelength solid laser
US6021140A (en) Polarization based mode-locking of a laser
CN211981132U (en) Electro-optical Q-switched cavity emptying laser
CN111478174A (en) Electro-optical Q-switched cavity emptying laser
CN115939919B (en) Solid laser based on Kerr lens mode locking
CN110011177B (en) Electro-optical radial birefringence Q-switch
CN102263364B (en) Transverse plane pump laser capable of high efficiently using pump light
CN110932070B (en) Dual-wavelength alternating Q-switching narrow pulse laser and output method
CN113937610A (en) YAG laser with orthogonal linear polarization birefringence and double frequency Nd
CN110635349B (en) Ultra-high repetition frequency narrow pulse width CO2Laser device
CN105006734B (en) A kind of 2 μm of lasers that half Intracavity OPO is formed based on body grating
US20160334691A1 (en) Non-planer, image rotating optical parametric oscillator
CN101710666A (en) Semiconductor laser pump single longitudinal mould and frequency laser
CN110880670A (en) High-efficiency optical parametric oscillator with adjustable threshold value
CN110932069A (en) Ultrahigh repetition frequency narrow pulse single-wavelength alternate Q-switched laser output method and laser
CN102487177A (en) Electro-optical crystal, laser resonant cavity and laser
CN101404379A (en) LD end face pump standing wave cavity single-frequency solid laser
CN218242548U (en) Large-energy dual-wavelength laser

Legal Events

Date Code Title Description
GR01 Patent grant
GR01 Patent grant