CN218867624U

CN218867624U - Short pulse laser source and laser equipment

Info

Publication number: CN218867624U
Application number: CN202222925343.1U
Authority: CN
Inventors: 刘民哲; 赵坤; 王丽莎; 刘梦霖; 翟瑞占; 贾中青; 李欢欣; 张明山
Original assignee: Laser Institute of Shandong Academy of Science
Current assignee: Laser Institute of Shandong Academy of Science
Priority date: 2022-11-03
Filing date: 2022-11-03
Publication date: 2023-04-14
Anticipated expiration: 2032-11-03

Abstract

The utility model discloses a short pulse laser source and laser equipment, include: the laser system comprises a resonant cavity, a laser module and an output mirror, wherein the resonant cavity comprises a total reflection mirror, a first laser side pump module, a reflecting mirror, a second laser side pump module and the output mirror which are arranged along a light path in sequence; the distances from the centers of equivalent thermal lenses of laser crystals in the first laser side pump module and the second laser side pump module to the reflector are equal, and the first laser side pump module and the second laser side pump module are semiconductor pump modules; the reflector is used for reflecting laser in the cavity, so that a laser light path of the resonant cavity is V-shaped to form a V-shaped folding cavity. The utility model discloses short pulse laser source and laser equipment, the pulse laser of stable output 1319nm wavelength has the advantage among the clinical medical treatment operation, has less tissue heat damage, has higher work efficiency simultaneously concurrently.

Description

Short pulse laser source and laser equipment

Technical Field

The utility model relates to a pulse laser technical field especially relates to a short pulse laser source and laser equipment.

Background

In recent years, lasers are widely applied in the medical field, particularly clinical surgery, and diversification and difference of application are determined by different action mechanisms of lasers with different wave bands and biological tissues. For example, holmium laser and thulium laser with wavelength of 2 μm are commonly used in urinary surgery, mid-infrared laser with wavelength of 9.3 μm is used in dental surgery, and near-infrared laser with wavelength of 970nm-1500nm can reach several millimeters in depth of tissue, thus being beneficial to hemostasis of various tissues.

In the field of tumor surgical resection, particularly in lung metastatic tumor resection, on one hand, methods such as an ultrasonic knife, an electric knife, a cutting stapler and the like are commonly adopted at present, but the defects that the lung tissue is easy to leak air after the operation, and the sealing effect is often achieved by matching with silk suture, and although the cutting stapler is convenient and quick to use, the lung tissue is easy to shrink after the operation. YAG laser with 1064nm wavelength can be used in conventional tumor laser ablation, but because the absorption coefficient of human tissue to this wavelength is small, edema or inflammation will occur due to the severe heat diffusion effect during ablation.

Compared with the laser with the wavelength of 1064nm, the laser with the wavelength of 1319nm as represented by 1.3 μm has obvious advantages, and the laser with the wavelength can provide better cutting and coagulating effects due to the absorption rate of the laser in water which is 10 times higher and sufficient laser scattering effect, and can strengthen the structural stability around the tissue cutting area.

However, the stability of 1319nm laser light generated by conventional lasers and laser devices is not high, and the 1319nm wavelength cannot be widely used in medical surgery.

SUMMERY OF THE UTILITY MODEL

The utility model provides a short pulse laser source and laser equipment for solve the unable problem that produces the laser of high stability 1.3 mu m of current laser instrument.

The utility model discloses a first aspect provides a short pulse laser source for produce the continuous and pulse laser of 1.3 mu m wavelength, include:

the resonant cavity comprises a total reflection mirror, an acousto-optic Q-switch, an optical gate switch, a first laser side pump module, a reflector, a second laser side pump module and an output mirror which are sequentially arranged along an optical path;

the acousto-optic Q-switch is used for generating nanosecond pulses and modulating the laser output repetition frequency;

the optical shutter switch is used for cutting off the transmission of the laser when the optical shutter switch is turned off, and is also used for enabling the laser to be transmitted in the resonant cavity and output by the output mirror when the laser works;

the distances from the centers of the equivalent thermal lenses of the first laser side pump module and the second laser side pump module to the reflector are equal, and the first laser side pump module and the second laser side pump module are semiconductor pump modules;

the reflector is used for reflecting laser in the cavity so that a laser light path of the resonant cavity is V-shaped to form a V-shaped folding cavity;

the curvature radius of the reflector is R2, R2=2 XF, wherein F is the equivalent focal length of the first laser side pump module and the second laser side pump module;

the optical length of the resonant cavity is M, M = M1+2 × M2+ M3, wherein M1 is the distance between the centers of the equivalent thermal lenses of the output mirror and the second laser side pump module, M2 is the distance between the centers of the equivalent thermal lenses of the first laser side pump module and the second laser side pump module and the reflector, and M3 is the distance between the centers of the equivalent thermal lenses of the total reflector and the first laser side pump module.

Optionally, the short pulse laser source comprises a stable cavity determined by taking the output mirror as a reference surface, and the stable cavity is designed based on a V-shaped dynamic stable cavity; the structure and parameters of the stability chamber are determined as follows:

establishing an abcd matrix of resonant cavities:

the ABCD matrix formula in the corresponding resonant cavity is:

/>

k is a resonant cavity, R1 is the curvature radius of the total reflection mirror, and R3 is the curvature radius of the output mirror;

the stable cavity has the stable condition of 0-G1G 2<1, the stable cavity comprises a first stable area and a second stable area which are determined based on the stable condition, the working state of the short pulse laser source enters the second stable area from the first stable area, and the working point of the short pulse laser source is set in the second stable area.

Optionally, the distance M1 between the output mirror and the second laser side pump module is 150mm;

the distance M2 between the first laser side pump module and the second laser side pump module and the reflector is 125 mm-175 mm;

the distance M3 between the total reflection mirror and the first laser side pump module is 400 mm-600 mm;

the total reflection mirror is a cavity mirror of a resonant cavity and used for transmitting laser beams, the total reflection mirror adopts a plane mirror, and the damage threshold value>10J/cm ² Reflectivity of>99.9％。

The output mirror is an output cavity mirror of the resonant cavity and is used for transmitting the laser beam, and the bandwidth of the output mirror<10nm, damage threshold>15J/cm ² Reflectance of 70% to 85%;

optionally, the operation wavelength of the acousto-optic Q-switch is 1319nm, the optical aperture is 4mm, the carrier frequency is 27MHz ± 0.1MHz, the rise time of the electrical pulse is less than 200ns, and the control signal level is TTL level.

Optionally, the method further comprises:

the spectroscope is arranged on a downstream light path of the output mirror and used for transmitting and reflecting the laser output by the output mirror to form a path of transmission light and a path of reflection light;

the focusing lens and the power meter probe are sequentially arranged along the light path of the transmission light, the focusing lens is used for focusing the transmission light to the power meter probe, and the power meter probe is used for performing self-feedback regulation on the power of the short pulse laser source according to the detected power intensity of the transmission light;

the optical couplers and the indicating light sources are distributed on two sides of the spectroscope, the optical couplers are positioned on a light path of the reflected light, and the indicating light sources are positioned on the opposite side of the light path of the reflected light;

the indicating light source is used for emitting indicating light along the light path direction of the reflected light, so that the indicating light is transmitted by the spectroscope and then enters the optical coupler;

the optical coupler is used for coupling the received reflected light and the indication light.

A second aspect of the present invention provides a laser device, which includes the short pulse laser source, the electronic control module, the cooling system and the subscriber unit, wherein the short pulse laser source, the electronic control module and the cooling system are all connected to the subscriber unit;

the electric control module is used for controlling the short pulse laser source and the cooling system to work;

the cooling system is used for radiating heat for the short-pulse laser source;

the user unit is used for carrying out parameter adjustment on the output laser of the short-pulse laser source.

Optionally, the laser hand tool is further included and is used for connecting the short pulse laser source and irradiating the laser output by the short pulse laser source to a specified position;

the laser hand tool comprises an optical fiber connector, a multimode optical fiber, a first plano-convex lens, a lens barrel, a second plano-convex lens, a window sheet, a hand tool tube shell and a positioning connector, wherein the optical fiber connector is respectively connected with the short pulse laser source and the multimode optical fiber; the interior of the hand tool tube shell is provided with a channel along the length direction of the hand tool tube shell, so that the multimode optical fiber is arranged in the hand tool tube shell from the first end of the hand tool tube shell along the channel in a penetrating way and is connected with the first plano-convex lens arranged in the hand tool tube shell; the second end of the hand tool case is provided with the positioning joint.

Optionally, the electronic control module comprises:

a power supply unit for outputting a direct current and supplying power to the short pulse laser source, the cooling system and the display device;

and the control unit is used for controlling the cooling system and the working state of the short pulse laser source.

Optionally, the subscriber unit comprises:

the display device is used for storing upper computer software which is used for realizing the input and adjustment of parameters of the short pulse laser source and the instruction sending operation;

and the pedal is connected with the laser through a line and is used for controlling the working state of the laser.

The utility model provides a short pulse laser source and laser equipment, design method based on V type dynamic stabilization chamber, utilize the total reflection mirror in the resonant cavity, first laser side pump module, the speculum, the position relation of second laser side pump module and output mirror, and the center wavelength of total reflection mirror and output mirror, the bandwidth can be stable output 1.3 mu m wavelength continuous and pulse laser, clinical medical treatment operation is used and is had the advantage, and, utilize V type dynamic stabilization chamber design, simultaneously through acousto-optic modulation Q switch and optical gate switch cooperation, form self-feedback adjustment mechanism, can realize the laser output of 1319nm wavelength of high stability, compare in the 1064nm and the 532nm wavelength laser that the tradition used, have less tissue thermal damage, have higher work efficiency simultaneously concurrently.

In addition, the short pulse laser source, the electronic control module and the cooling system are connected with the user unit, and the short pulse laser source, the electronic control module and the cooling system are controlled through the user unit, so that the applicability of equipment is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of a stable cavity of a short pulse laser source according to the present application;

FIG. 2 is a schematic diagram of a stable region of a short pulse laser source according to the present application;

FIG. 3 is a schematic diagram of a laser apparatus according to the present application;

fig. 4 is a schematic diagram illustrating a power self-feedback adjustment process of a laser device according to the present application;

FIG. 5 is a schematic diagram of a laser hand tool of a laser apparatus of the present application;

FIG. 6 is a schematic view of a positioning arm and a retaining ring of a laser apparatus of the present application;

FIG. 7 is a data graph of the laser wavelength output by the short pulse laser source of a laser apparatus of the present application;

FIG. 8 is a data graph of laser power output by a laser handpiece at different operating currents for a laser apparatus of the present application;

FIG. 9 is a plot of root mean square stability and peak stability for a laser device of the present application;

FIG. 10 is a graph of lung pathology at different laser powers for a laser apparatus of the present application;

FIG. 11 shows a laser apparatus of the present application cutting 1cm at different laser powers ² Time required for tissue testing.

Reference numerals:

100-short pulse laser source; 101-total reflection mirror; 102-acousto-optic Q-switch; 103-shutter switch; 104-a first laser side pump module; 105-a polarizing plate; 106-a second laser side pump module; 107-output mirror; 108-a beam splitter; 109-an indicator light source; 110-a focusing lens; 111-a power meter probe; 112-an optical coupler; 200-an electronic control module; 300-a cooling system; 400-a user operating unit; 401-a display device; 402-pedaling; 403-laser handpieces; 4031-fiber splice; 4032-multimode optical fiber; 4033-handpiece cartridge; 4034-mirror ring; 4035-first plano-convex lens; 4036-column lens; 4037-a second plano-convex lens; 4038-window slice; 4039-gasket; 4040-a positioning joint; 40401-a retaining ring; 40402-positioning arm.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The present application provides a short pulse laser source for generating a pulsed laser light of 1.3 μm wavelength.

FIG. 1 is a schematic diagram of a stable cavity of a short pulse laser source according to the present application.

As shown in fig. 1, the short-pulse laser source includes a resonant cavity (not shown in fig. 1), and an all-mirror 101, an acousto-optic Q-switch 102, a shutter switch 103, a first laser-side pump module 104, a mirror, a second laser-side pump module 106, and an output mirror 107 located in the resonant cavity in that order along the optical path.

The total reflection mirror 101 is a cavity mirror of a resonant cavity, preferably a plane mirror, the coating center wavelength of the total reflection mirror 101 is 1319nm, and the damage threshold value>10J/cm ² Reflectivity of>99.9％。

An acousto-optic Q-switch 102 is used to generate nanosecond pulses and modulate the laser output repetition rate.

The shutter switch 103 is used to cut off the transmission of the laser light when turned off, and is also used to cause the laser light to be transmitted in the cavity and output from the output mirror when the laser is operated.

The equivalent thermal lens centers of the first laser side pump module 104 and the second laser side pump module 106 are equidistant from the mirror, and the first laser side pump module 104 and the second laser side pump module 106 are semiconductor pump modules.

The first laser side pump module 104 and the second laser side pump module 106 are both semiconductor pump modules, and are composed of 3*3 arrays formed by 9 bars, preferably, the wavelength of the semiconductor pump module is 807.4nm, the maximum pump power of each bar is 40W, the laser crystal rod is Nd: YAG crystal, and the size is Nd: YAG crystal which adopts water cooling heat dissipation

Nd ³⁺ The doping concentration of (2) was 0.6%.

The output mirror 107 is used to output laser light. Preferably, the output mirror 107 is a flat mirror, and forms a flat cavity with the all-mirror 101. Because of the different effects of different wavelength laser applications, a fixed single wavelength laser is usually required for specific requirements, such as lung tumor ablation, and for laser crystal Nd: YAG, the resonant cavity can easily generate other adjacent band laser such as 1338nm laser besides 1319nm laser according to fluorescence spectrum and energy level transition. Therefore, the application limits the coating parameters of the output mirror 107, and specifically can limit the central wavelength of the output mirror 107 to 1319nm; in addition, the present application may also limit the bandwidth of the output mirror 107<10nm, damage threshold>15J/cm ² The reflectivity is 70% to 85% in order to guarantee the output laser wavelength.

The reflector is used for reflecting the light path and is arranged at the switching part of the resonant cavity so as to make the light path of the resonant cavity be V-shaped and form a V-shaped folding cavity. The effect of the reflector is: on one hand, the total reflection mirror 101 can be replaced, the optical path of the optical path structure is reduced, and the whole volume of a laser (short pulse laser source) is shortened; on the other hand is used for restricting the output laser polarization state of resonance cavity, realizes that vertical polarization laser is exported by output mirror 107, guarantees that extinction ratio >200, compares with the output laser of non-linear partially, has higher power stability, can promote the performance of laser instrument and laser equipment.

The mirror may be replaced by a polarizer 105 (the polarizer 105 is used to replace the mirror for illustration in the following description), and the small angle deflection of the polarizer 105 may affect the reflectivity and extinction ratio of the linearly polarized light, and ultimately the output of the pulsed laser. Therefore, the polarizing plate 105 is preferably a 25 ° polarizing plate, and the plating parameters are that the center wavelength is 1319nm, the bandwidth is 5nm, the polarization extinction ratio is >1000, and the vertical polarized light reflectance is >99.7@25 °, so as to ensure the output of laser light.

In order to ensure that the laser outputs at a wavelength of 1.3 μm with high stability, the resonant cavity and the mirror may be further defined as follows:

preferably, the optical length of the resonant cavity is M:

M＝M1+2×M2+M3；

wherein, M1 is the distance between the equivalent thermal lens centers of the output mirror 107 and the second laser side pump module 106, M2 is the distance between the equivalent thermal lens centers of the first laser side pump module 104 and the second laser side pump module 106 and the reflector, and M3 is the distance between the equivalent thermal lens centers of the total reflection mirror 101 and the first laser side pump module 104.

The radius of curvature of the mirror is R2:

R2＝2×F；

where F is the equivalent focal length of the first laser side pump module 104 and the second laser side pump module 106.

In this embodiment, the optical path of the resonant cavity is designed to form a V-shaped folded cavity, which can reduce energy loss, and limit the corresponding holophote 101, the first laser side pump module 104, the polarizer 105, the second laser side pump module 106, and the output mirror 107, thereby ensuring that the output mirror 107 can stably emit pulse laser with a wavelength of 1.3 μm.

In one embodiment, the working wavelength of the acousto-optic Q-switch is 1319nm, the optical aperture is 4mm, the carrier frequency is 27MHz +/-0.1 MHz, the rising time of an electric pulse is less than 200ns, and the level of a control signal is TTL level.

Specifically, the acousto-optic Q-switch 102 is used for generating nanosecond pulses and modulating the laser output repetition frequency, the working wavelength of the acousto-optic Q-switch 102 is 1319nm, the optical aperture is 4mm, the carrier frequency is 27MHz ± 0.1MHz, the rise time of the electric pulses is less than 200ns, and the control signal level is TTL level.

As shown in fig. 3, the shutter switch 103 is used for the generation and the turn-off of the laser light, and can also function as a protector for devices and workers.

Specifically, when the short-pulse laser source stops working, the shutter switch 103 receives a stop instruction, the shutter switch 103 is closed, and the transmission of the laser in the resonant cavity is cut off, at this time, the resonant cavity has no laser output; when the short-pulse laser source 100 starts to operate, the shutter switch 103 receives an opening instruction, the shutter switch 103 is opened, and the laser oscillates in the resonant cavity to form stable laser which is transmitted and output by the output mirror 107 to enter a subsequent optical path.

In this embodiment, the acousto-optic Q-switch 102 and the shutter switch 103 are used to correspondingly control the modulation and on-off of the repetition frequency of the laser, so as to ensure the modulation of the repetition frequency of the laser in the resonant cavity and control the laser output.

In one embodiment, a light transmission matrix abcd is established, the alternation of laser light on different folding surfaces is determined, and the pulse laser output with high stability at the position of the working point of the short pulse laser source is obtained.

Specifically, the short pulse laser source includes a stable cavity determined with the output mirror 107 as a reference plane, and the stable cavity is designed based on a V-shaped dynamic stable cavity; the structure and parameters of the stability chamber are determined as follows:

establishing an abcd matrix of resonant cavities:

the ABCD matrix formula in the corresponding resonant cavity is:

/>

k is a resonant cavity, R1 is the curvature radius of a total reflection mirror, R3 is the curvature radius of an output mirror 107, the stability condition of the stable cavity is obtained by the formula and is 0-G1-G2 <1, and a stable region diagram of the V-shaped folding resonant cavity and a motion curve of a working point of the short pulse laser source based on the V-shaped dynamic stable cavity design are obtained by the G1-G2.

FIG. 2 is a schematic diagram of a stable region of a short pulse laser source according to the present application.

As shown in fig. 2, the stability chamber includes a first stability region and a second stability region determined based on a stability region map. The motion curve of the short pulse laser source in the working state is a straight line, and the path in the direction indicated by the arrow in fig. 2 is the motion track of the laser working point. Along with the increase of the working current of the laser, the laser working point enters a second stable region from a first stable region along the direction of a dotted line. In order to obtain a high stable pulse laser output effect, the laser operating point may be set in the second stable region, as shown by point a in fig. 2, and the laser operating point may be set at point a. Compared with other cavity-type resonant cavities, the slope of the track of the laser working point is larger, and the range of the stable region is wider, so that the output laser is easier to be in a stable region state, and meanwhile, due to the increase of the stable region, the adjustment and the later maintenance of the laser become simple.

In addition, in order to achieve stabilization of the pulsed laser output of the V-folded resonator and to facilitate adjustment and maintenance, it is preferable to set the distance between the output mirror 107 and the second laser side pump module 106 to 150mm; and the distances between the first laser side pump module 104 and the second laser side pump module 106 to the polarizing plate 105 are set to be the same. According to the actual situation, the distance between the first laser side pump module 104 and the second laser side pump module 106 to the polarizing plate 105 may be set to any value between 125mm and 175 mm. In a stable working state of the resonant cavity laser, the selectable range of the total reflection mirror 101 and the first laser side pump module 104 is any value between 400mm and 600 mm.

By the above preferable setting, it is further ensured that the pulsed laser can stably output 1319nm high-stability laser light.

Fig. 3 is a schematic structural diagram of a laser apparatus according to the present application.

As shown in FIG. 3, in one embodiment, the short pulse laser source further comprises a beam splitter 108, a focusing lens 110, a power meter probe 111, an optical coupler 112, and an indicator light source 109.

The beam splitter 108 is disposed on a light path downstream of the output mirror 107, that is, a light path behind the resonator output mirror 107, and is configured to split the laser light output by the output mirror 107 to form a path of transmitted light and a path of reflected light.

Specifically, most of the laser light passing through the beam splitter 108 is reflected light, enters the optical coupler 112, and a small amount of transmitted light is focused to the power meter probe 111 through the focusing lens 110 for real-time power monitoring and self-feedback adjustment.

In order to improve the final output laser power, preferably, the splitting ratio of the beam splitter 108 is 99 @ 1@45 °, and the characteristic parameters of the beam splitter 108 further include the central wavelength of the plated film being 1319nm and the damage threshold value>15J/cm ² 。

The focusing lens 110 and the power meter probe 111 are sequentially arranged along the optical path of the transmitted light, the focusing lens 110 is used for focusing the transmitted light to the power meter probe 111, and the power meter probe 111 is used for self-feedback adjustment of the power of the short pulse laser source according to the detected power intensity of the transmitted light.

Preferably, the focusing lens 110 is a short focus lens with a focal length F <50mm and a coating reflectivity <0.2% @1319nm. Because the transmission laser power is smaller, the adoption of the focusing lens 110 can improve the laser power density, is more favorable for the receiving of the power meter probe 111, and improves the detection sensitivity.

Preferably, the power meter probe 111 is of a photoelectric type, with an effective photosensitive diameter of 5mm, a minimum detection power of 0.1mW, and a resolution of 0.05mW, so as to better achieve laser output power monitoring and self-feedback regulation.

The power meter probe 111 receives 1% of the transmitted light of the output mirror 107 through the beam splitter 108. For any of the different laser output powers, the power meter probe 111 converts the corresponding transmitted light received into a current signal.

The indicating light source 109 is a semiconductor laser, and the indicating light source 109 is used for emitting indicating light along the light path direction of the reflected light, so that the indicating light is transmitted by the spectroscope 108 and then enters the optical coupler 112.

Specifically, in order to meet the special application requirements of laser medical surgical tissue resection and the like, the indication light source 109 in the present application should not adopt red light and visible light, compared with an industrial laser and a laser device. Preferably, the wavelength of the indicating light source 109 is 530nm, the voltage is 2.7-3.5V, and the power is adjustable within the range of 5mW-300mW, so that the change of the laser brightness is realized, and the applicability under the actual application scene is improved.

The optical coupler 112 is a C-port fiber optic adapter for coupling the received reflected light and the indicator light.

Specifically, the optical coupler 112 is used to couple the 1319nm laser light reflected by the beam splitter 108 and the green light emitted by the pointing light source 109 transmitted through the beam splitter 108. Preferably, the optical fiber interface end of the optical fiber adapter is an SMA905 interface with a collimating lens, the central wavelength of the coating is 1319nm, the transmittance is greater than 99.8%, the transmittance for 530nm laser is greater than 90%, and the coupling efficiency is greater than or equal to 96%. In order to monitor the coupling efficiency in real time and prevent the optical coupler 112 from overheating or burning due to external factors such as mechanical vibration, a temperature sensor is provided at the optical coupler 112 for monitoring the real-time temperature of the optical coupler 112. The outer shell is tightly attached to and fixes the temperature sensor and is connected with the electronic control module 200, real-time temperature monitoring is facilitated, and protection of the laser and prolonging of the service life of the laser are facilitated.

The present application also provides an embodiment of a laser apparatus having a short pulse laser source, corresponding to the previous embodiment, as shown in fig. 3. The laser device comprises the short pulse laser source 100, the electronic control module 200, the cooling system 300 and the user unit 400, wherein the short pulse laser source 100, the electronic control module 200 and the cooling system 300 are all connected with the user unit 400.

Fig. 4 is a schematic diagram of a power self-feedback adjustment process of a laser device according to the present application. The power self-feedback adjustment process can be implemented by the electronic control module 200, the short pulse laser source 100 and the user unit 400 together.

The laser device and the power self-feedback adjusting process thereof provided by the present application are specifically described below with reference to fig. 3 and 4.

The dashed lines in fig. 3 are power lines to the electronic control module 200, wherein the electronic control module 200 is used to control the operation of the short pulse laser source 100 and the cooling system 300.

Specifically, the electronic control module 200 may include a power supply unit and a control unit.

And the power supply unit is used for outputting direct current and supplying power to the short-pulse laser source 100, the cooling system 300 and the display device 401, and further, the power supply unit can also supply power to the first laser-side pump module 104, the second laser-side pump module 106, the shutter switch 103, the acousto-optic Q-switch 102, the indicating light source 109, the cooling system 300 and the display device 401.

And the control unit is used for controlling the working states of the cooling system 300 and the short pulse laser source 100, and further, the control unit can monitor and process signals of various devices, wherein the monitored and processed signals at least comprise a power meter probe 111 feedback signal, a sensor feedback signal, a short pulse laser source 100 current and voltage working signal, a pedal 402 feedback signal, a display device 401 control signal and the like.

Illustratively, during the actual operation of the short pulse laser source 100, the control unit can monitor the electrical signal transmitted by the power meter probe 111 in real time, so as to realize real-time power monitoring of the short pulse laser source 100. When the actual power of the short pulse laser source 100 is higher than or lower than a certain set interval (for example, the actual power exceeds ± 10% of a set value, which is not specifically limited by the present application), the electronic control module 200 immediately turns off the power supply to stop light emission, thereby preventing damage to related devices.

In another example, when the laser power received by the power meter probe 111 is low and the corresponding current signal is weak, the precision of the final output laser power calibration may be affected, so that the current signal may be received and amplified through the transimpedance amplifier (TIA) of the control unit, the final output laser power calibration is finally achieved, and the precision of the self-feedback power adjustment is improved.

In the working process of the short pulse laser source 100, the control unit calculates and adjusts working currents corresponding to the two laser side pumps according to a feedback signal of the power probe through a PID control algorithm (the PID control algorithm is a control algorithm integrating three links of proportion, integration and differentiation), increases or decreases the working currents in steps of 0.1A, increases or decreases the output power of the semiconductor pump in a small range, and further enables the fluctuation of the output power not to exceed +/-2% of a set value; meanwhile, the control unit monitors the temperature of the optical coupler 112 in real time, and immediately turns off the power supply when the temperature exceeds 35 ℃, so as to prevent the device from being damaged, and finally realize the power self-feedback regulation function.

The cooling system 300 is a water cooling system and is used for radiating heat for the short pulse laser source 100, preferably, the temperature range of the cooling system 300 is 5-35 ℃, and the refrigerating capacity is 5kW @20 ℃.

In one implementation, the cooling system 300 may include a circulation pump, an overload relay, and a thermal protection module. The temperature control precision of the cooling system 300 is +/-0.1 ℃, the stability of the laser output by the semiconductor pump can be ensured, and the stability of the laser output by the short pulse laser source 100 is further improved.

Wherein the circulation pump is used for dissipating heat of the short pulse laser source 100. And a circulating pump is arranged at the short pulse laser source 100 to dissipate heat of the short pulse laser source 100, and the circulating pump is preferably controlled to have a flow rate of 35L/min.

And the overload relay is arranged on a line of the circulating pump and used for sending a first abnormal signal to the electronic control module 200 when the circulating pump works abnormally, for example, the circulating pump is in a cooling water cut-off state under the working state of the short pulse laser source 100, and the electronic control module 200 sends a command to turn off the power supply unit of the short pulse laser source 100 after receiving the fed back first signal.

And the thermal protection module is arranged on a circuit of the short-pulse laser source 100 and used for sending a second abnormal signal to the electronic control module 200 when the temperature of the short-pulse laser source 100 exceeds a set threshold, and the electronic control module 200 sends an instruction to turn off the power supply unit of the short-pulse laser source 100 after receiving the fed-back second signal.

The user unit 400 is used for parameter adjustment of the output laser of the short pulse laser source 100. The user unit 400 may comprise a display device 401 and a foot rest 402.

The display device 401 is used to store upper computer software, the upper computer software has an operation interface, and a user can input and adjust parameters of the short pulse laser source 100 and send commands through the operation interface.

The pedal 402 is connected with the laser through a line and is used for controlling the working state of the laser. The user is facilitated to control the short pulse laser source 100 through the foot pedal 402. For example, the short-pulse laser source 100 is turned off in a normal operating state, when a user steps on the pedal 402 when the short-pulse laser source 100 is required to emit laser, the electronic control module 200 receives a signal and sends an "open" command to the shutter switch 103 in the short-pulse laser source 100, and the laser oscillates in the resonant cavity to form a pulse laser output.

Fig. 5 is a schematic structural diagram of a laser hand tool of a laser device according to the present application.

As shown in fig. 5, in one embodiment, the laser device further includes a laser hand 403, and the laser hand 403 is used to connect the short pulse laser source 100 and irradiate the laser light output by the short pulse laser source 100 to a designated position.

The laser hand tool 403 includes an optical fiber connector 4031, a multimode optical fiber 4032, a first plano-convex lens 4035, a lens barrel 4036, a second plano-convex lens 4037 and a window plate 4038; the optical fiber connector 4031 is respectively connected with the short-pulse laser source 100 and the multimode optical fiber 4032, the end of the multimode optical fiber 4032 opposite to the optical fiber connector 4031 is coaxial with the first plano-convex lens 4035, the lens barrel 4036 is arranged between the first plano-convex lens 4035 and the second plano-convex lens 4037, and the window sheet 4038 is arranged at the end, opposite to the first plano-convex lens 4035, of the second plano-convex lens 4037 and is attached to the second plano-convex lens 4037.

Further, the optical fiber connector 4031 is preferably an SMA905 connector (SMA 905 is a type of connector), and one end of the optical fiber connector 4031 is fixed at the rear end of the optical coupler 112 and is used for receiving 1319nm laser light and 530nm indicating light coupled out by the optical coupler 112; the other end of the optical fiber connector 4031 is connected with a multimode optical fiber 4032.

The multimode fiber 4032 may be selected from fibers with different core diameters according to different application requirements, for example, the core diameter of the fiber is 400 μm, 600 μm, or 800 μm, and the diameter of the final output laser spot may be affected by the different core diameters of the multimode fiber 4032, which may be specifically selected according to the requirements.

The first plano-convex lens 4035 is used for collimating laser light output by the multimode fiber 4032, the focal plane of the first plano-convex lens 4035 is fixed at a position which is one time of the focal distance F1 from the output end face of the multimode fiber 4032, and the focal distance of the second plano-convex lens 4037 is F2. The first plano-convex lens 4035 and the second plano-convex lens 4037 constitute a 4F optical system (the 4F optical system is one of a linear optical information processing system, a filter system).

The distance between the focal plane of the second plano-convex lens 4037 and the focal plane of the first plano-convex lens 4035 is F1+ F2, so that beam expansion of laser spots is realized, and the multiple of F2/F1 is equal to the beam expansion multiple of the laser spots.

In order to ensure the size of the output light spot, it is preferable that the first plano-convex lens 4035 and the second plano-convex lens 4037 have a smaller geometric parameter size, wherein the diameter is 8-10 mm, the transmittance for 1319nm laser is >99.8%, and the transmittance for the indicator light source 109 is >92%. And a first plano-convex lens 4035 with the focal length of 10mm and a second plano-convex lens 4037 with the focal length of 15mm are adopted to expand the laser spot by 1.5 times, namely the diameter of the laser spot focused by a 4F system is 900 micrometers. In addition, 600 μm is used for the multimode optical fiber 4032.

Further, in order to control and adjust the pitch of the first plano-convex lens 4035 and the second plano-convex lens 4037 in the 4F optical system, a lens barrel 4036 is placed between the first plano-convex lens 4035 and the second plano-convex lens 4037, and the pitch of the first plano-convex lens 4035 and the second plano-convex lens 4037 is adjusted by the lens barrel 4036.

The window sheet 4038 is tightly attached to the second plano-convex lens 4037 and is far away from the plane end of the first plano-convex lens 4035, the diameter of the window sheet 4038 is consistent with that of the second plano-convex lens 4037, and therefore the window sheet 4038 is used for preventing external dust and other pollutants from entering the laser hand tool 403 and preventing the pollutants from being attached to the surface of the second plano-convex lens 4037 and damaging a coating film and a device due to interaction of laser.

In this embodiment, the laser hand tool 403 can irradiate the laser beam output by the short pulse laser source 100 to a designated position, so as to apply the laser beam with 1319nm wavelength to the affected part to perform a corresponding surgical operation.

In one embodiment, the laser handpiece 403 further includes a handpiece housing 4033 and a positioning tab 4040, the handpiece housing 4033 having a channel therein along its length such that the multimode optical fiber 4032 is channeled from the first end of the handpiece housing 4033 along the channel into the handpiece housing 4033 and into engagement with the first plano-convex lens 4035 disposed in the handpiece housing 4033; the second end of the handpiece housing 4033 is provided with a locating tab 4040.

The outer circumferential wall of the handpiece tube 4033 is designed into a circumferential inwards concave shape, so that the handpiece tube 4033 is convenient to hold, the applicability of long-time laser medical treatment is improved, and the multimode optical fiber 4032 is firmly wrapped and fixed by the handpiece tube 4033. In order to fix the relative position of the multimode fiber 4032 and the first plano-convex lens 4035, a mirror ring 4034 is arranged at one end of the first plano-convex lens 4035 adjacent to the multimode fiber 4032, and the mirror ring 4034 is tightly attached to the first plano-convex lens 4035 through screwing, so that the multimode fiber 4032 and the first plano-convex lens 4035 are fixed, and the size of an output light spot is ensured.

Fig. 6 is a schematic diagram of a positioning arm and a fixing ring of a laser device according to the present application.

As shown in fig. 5 and 6, the retaining tab 4040 includes a retaining ring 40401 and a retaining arm 40402, the retaining ring 40401 being internally threaded such that the retaining ring 40401 can be threaded into the second end of the tool case 4033. The positioning arm 40402 and the fixing ring 40401 are of an integral structure, and the end faces of the positioning arm 40402 and the fixing ring 40401 form an included angle of 10-30 degrees.

Preferably, the positioning arm 40402 is angled at 16 ° from the retaining ring 40401. As shown in fig. 6, the positioning arm 40402 has a double-arm design, and the angle between the positioning arm 40402 and the fixing ring 40401 is 16 °, so that the view is not obstructed, and the operation is facilitated. The contained angle structural design is applicable to the tissue support of pressing close to under the long-time operation, improves the reliability of using, and the locating arm 40402 keeps away from the terminal surface of holding ring 40401 and adopts the chamfer design, prevents to use the in-process fish tail tissue of locating arm, and the preferred F2 of the focal plane distance of the summit of locating arm 40402 to second plano-convex lens 4037.

In order to adjust the position of the final output laser focusing point, a washer 4039 is arranged at the joint of the second end of the handpiece tube 4033 and the positioning joint 4040, the second end of the handpiece tube 4033 and the positioning joint 4040 can be stably connected by using the washer 4039, and the second end of the handpiece tube 4033 and the positioning joint 4040 can be adjusted in a small range, so that the position of the final output laser focusing point is ensured, and the washer 4039 can be selected to have different thicknesses of 1-3 mm according to the difference of tissue characteristics in practical application.

In a specific embodiment, the first laser side pump module 104 and the second laser side pump module 106 of the short-pulse laser source 100 are both 807nm semiconductor pumps, the maximum working current is 27.4A, the corresponding single modules are both 250W pump power, the laser crystals are both Nd: YAG crystals, and the size is Nd: YAG crystals

Nd ³⁺ The doping concentration of (2) is 0.6%.

Based on the ABCD matrix and the stable area design, the practical device geometric parameter limitation is realized by considering the engineering, and the distance between the first laser side pump module 104 and the second laser side pump module 106 from the polaroid 105 is 175mm; the distance between the total reflection mirror 101 and the first laser side pump module 104 is 500mm; the distance between the output mirror 107 and the second laser side pump module 106 is 150mm; the transmittance of the output mirror 107 was 85% @1319nm.

Fig. 7 is a data diagram of the laser wavelength output by the short pulse laser source 100 of the laser apparatus of the present application.

As shown in fig. 7, in the present embodiment, by the structural design of the resonant cavity of the short-pulse laser source 100, the 1.3 μm band laser output is realized. The laser output by the short pulse laser source 100 of the present application is actually measured by using an existing spectrum analyzer YOKOGAWA (AQ 6375B) with a resolution of 0.02nm, with a laser center wavelength of 1318.8320nm and a spectral width (3 dB) of 0.0279nm, thereby achieving the design purpose and original purpose of the present application.

Fig. 8 is a data graph of laser power output by a laser handpiece of a laser apparatus according to the present application at different operating currents.

In this embodiment, an existing power meter Thorlabs (S322C) may be adopted, and different working currents are set to test the average power of the laser output by the laser hand tool 403 in this application, as shown in fig. 8, corresponding power output data under different working currents, a dotted solid line represents continuous light output, when the laser side pump module reaches the maximum working current of 27.4A, the maximum 51.4W laser output is corresponded, and the extinction ratio is > 200; the modulation of the repetition frequency can be realized by adjusting the Q switch, a dotted line represents corresponding laser output power data under the repetition frequency of 4kHz, the maximum laser output of 34.8W can be realized, the pulse width is 180ns at the moment, and the corresponding laser single pulse energy is 8.7mJ.

Fig. 9 is a graph illustrating the root mean square stability and peak stability of a laser device of the present application.

As shown in fig. 9, in addition, data recording was performed for an average power corresponding to the maximum operating current at a repetition frequency of 4kHz for more than 4 hours by using a power meter Thorlabs (S322C), and stability of the average power of the laser output from the laser hand tool 403, including root mean square stability and peak-to-peak stability, was measured in a single step/0.3S, where the measured average power mean value was 34.82W, the maximum value was 35.03W, the minimum value was 34.07W, the root mean square stability was <0.41% RMS, and the peak-to-peak stability was <2.8%.

The test result shows that the power self-feedback adjusting function of the power meter probe 111 in the application can better guarantee the power stability of the final laser output, the performance of the laser equipment is improved, and the technical support is provided for practical application.

The application provides a laser equipment can be used for carrying out the lung excision application experiment.

Fig. 10 is a schematic diagram of pathological examination of lung tissue under different laser powers of a laser device according to the present application.

As shown in fig. 10, the experimental material was obtained from intact lobes of the normal porcine fresh cardiopulmonary system, and the lungs were mainly intubated and ventilated. The main bronchus is connected with the ventilation device, and the ventilation device is gradually pressurized and ventilated to observe the ventilation pressure when the bronchus stump leaks air, so as to observe the sealing effect of different lasers emitted by the short pulse laser source 100 on the bronchus. The experimental result shows that 5-grade and below bronchus can be completely sealed by laser, and no bronchus air leakage phenomenon is caused when 20mmHg is pressurized; and (3) when the laser power is 30W, a coagulation necrosis layer is about 2mm in the lung incisal edge structure layer, an inflammatory exudation layer is thinner by 2mm, pathological detection is carried out on the lung tissue, and the HE staining microscopic form of the tissue under the laser power of 30W is shown in figure 10.

FIG. 11 shows a laser apparatus of the present application cutting 1cm at different laser powers ² Schematic of the time required for tissue organization.

In addition, the practical application efficiency of the laser equipment provided by the application is that the peripheral lung tissue of the pig is measured by 1 multiplied by 1cm ² In the experimental data, as shown in fig. 11, the average required time is 120 ± 15s when the ablation is performed by using 10W laser with different laser powers, the ablation time is gradually decreased with the increase of the laser power, and the required ablation time is reduced to 37 ± 5s when the average laser power reaches 30W. Therefore, different laser powers can be selected according to different application requirements, and the applicability of the laser device provided by the application is improved.

In conclusion, the laser device provided by the application has high stability, is oriented to the field of laser medical surgery, and particularly has unique application advantages and high applicability in lung tissue resection, particularly peripheral tumors.

The above embodiments only express the specific embodiments of the present invention, and the description thereof is specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the concept of the present invention, several variations and modifications can be made, which all fall within the scope of the present invention.

Claims

1. A short pulse laser source for generating a pulsed laser light of 1.3 μm wavelength, comprising:

the resonant cavity comprises a total reflection mirror, an acousto-optic Q-switch, an optical gate switch, a first laser side pump module, a reflector, a second laser side pump module and an output mirror which are sequentially arranged along a light path;

the distances from the centers of equivalent thermal lenses of laser crystals in the first laser side pump module and the second laser side pump module to the reflector are equal, and the first laser side pump module and the second laser side pump module are semiconductor pump modules;

the optical length of the resonant cavity is M, M = M1+2 × M2+ M3, where M1 is an equivalent thermal lens center distance between the output mirror and the second laser side pump module, M2 is a distance between an equivalent thermal lens center of the first laser side pump module and the second laser side pump module and the reflecting mirror, and M3 is an equivalent thermal lens center distance between the total reflection mirror and the first laser side pump module.

2. The short pulse laser source of claim 1,

the short-pulse laser source comprises a stable cavity determined by taking the output mirror as a reference surface, the stable cavity is designed based on a V-shaped dynamic stable cavity, and the structure and parameters of the stable cavity are determined by the following steps:

establishing an abcd matrix of the resonant cavity:

the ABCD matrix formula corresponding to the resonant cavity is as follows:

/>

/>

wherein K is the resonant cavity, R1 is the curvature radius of the total reflection mirror, and R3 is the curvature radius of the output mirror;

the stable cavity is composed of a first stable area and a second stable area which are determined based on the stable condition, the working state of the short pulse laser source enters the second stable area from the first stable area, and the working point of the short pulse laser source is arranged in the second stable area.

3. The short pulse laser source of claim 1,

the distance M1 between the output mirror and the second laser side pump module is 150mm;

the total reflection mirror is a cavity mirror of the resonant cavity and is used for transmitting laser beams, the total reflection mirror adopts a plane mirror, and the damage threshold value>10J/cm ² Reflectivity of>99.9％；

The output mirror is an output cavity mirror of the resonant cavity and is used for outputting the laser beam, and the bandwidth of the output mirror<10nm, damage threshold>15J/cm ² The reflectance is 70% to 85%.

4. The short pulse laser source of claim 1 wherein the acousto-optic Q-switch has an operating wavelength 1319nm, an optical aperture of 4mm, a carrier frequency of 27MHz ± 0.1MHz, an electrical pulse rise time <200ns, and the control signal level is a TTL level.

5. The short pulse laser source of claim 1, further comprising:

the focusing lens and the power meter probe are sequentially arranged along the light path of the transmitted light, the focusing lens is used for focusing the transmitted light to the power meter probe, and the power meter probe is used for performing self-feedback regulation on the power of the short pulse laser source according to the detected power intensity of the transmitted light;

the optical coupler and the indicating light source are distributed on two sides of the spectroscope, the optical coupler is positioned on the light path of the reflected light, and the indicating light source is positioned on the opposite side of the light path of the reflected light;

the optical coupler is used for coupling the received reflected light and the received indication light.

6. A laser device comprising the short pulse laser source of any one of claims 1-5, an electronic control module, a cooling system, and a user unit, the short pulse laser source, the electronic control module, and the cooling system all being connected to the user unit;

the cooling system is used for dissipating heat for the short pulse laser source;

7. The laser device according to claim 6, further comprising a laser hand tool for connecting the short pulse laser source to irradiate the laser light outputted from the short pulse laser source to a designated position;

the laser hand tool comprises an optical fiber connector, a multimode optical fiber, a first plano-convex lens, a lens barrel, a second plano-convex lens, a window sheet, a hand tool tube shell and a positioning connector, wherein the optical fiber connector is respectively connected with the short pulse laser source and the multimode optical fiber, the multimode optical fiber deviates from the optical fiber connector, one end of the multimode optical fiber is coaxial with the first plano-convex lens, the lens barrel is arranged between the first plano-convex lens and the second plano-convex lens, and the window sheet is arranged at one end of the second plano-convex lens, which deviates from the first plano-convex lens, and is attached to the second plano-convex lens; the interior of the hand tool tube shell is provided with a channel along the length direction of the hand tool tube shell, so that the multimode optical fiber is arranged in the hand tool tube shell from the first end of the hand tool tube shell along the channel in a penetrating way and is connected with the first plano-convex lens arranged in the hand tool tube shell; the second end of the hand tool case is provided with the positioning joint.

8. The laser apparatus of claim 6, wherein the electronic control module comprises:

9. The laser apparatus of claim 8, wherein the subscriber unit comprises:

the display device is used for storing upper computer software, and the upper computer software is used for realizing the input, adjustment and instruction sending operation of the parameters of the short pulse laser source;

and the pedal is connected with the short pulse laser source through a line and is used for controlling the working state of the short pulse laser source.