Hundred-picosecond laser capable of compensating light spots under high repetition frequency

Abstract

The invention relates to a hundred-picosecond laser capable of compensating light spots under high repetition frequency. The hundred-picosecond laser comprises a seed source, an amplification crystal, a driver, a reflector, a compensation lens and a light guide arm transmission system, the seed source can generate laser; laser generated by the seed source is amplified by the amplification crystal; the laser amplified by the amplification crystal is reflected to the light guide arm transmission system through the reflector; and the compensation lens is driven by the driver and can be connected into and separated from a light path between the amplification crystal and the light guide arm transmission system. According to the hundred-picosecond laser capable of compensating the light spot under the high repetition frequency, the problem that the size of the light spot of the laser is sharply reduced due to the influence of a thermal lens effect under the high repetition frequency can be effectively solved. It is guaranteed that the actual light spot output diameter of the laser is consistent with the set light spot diameter, the energy density is consistent, and clinical application can be safer and more efficient through accurate energy control.

Description

Technical Field

[0001] The invention belongs to the field of laser technology, and in particular relates to a hundred-picosecond laser capable of compensating for light spots under high repetition rate. Background Art

[0002] Since picosecond laser was approved by the FDA for tattoo removal and treatment of benign pigmented lesions in 2012, more and more studies have shown that picosecond laser is more advantageous in tattoo pigment removal with fewer side effects. In recent years, with the development of cosmetic medicine, picosecond laser has also been used in exogenous and endogenous pigment removal, acne scar treatment, photoaging improvement and wrinkle removal.

[0003] The frequency of the 100-picosecond laser used in medical beauty is generally 1-10Hz. There are currently three main technical routes. The first is that the nanosecond laser generated by the seed source laser is amplified and finally enters the SBS medium pool for compression. The compressed laser is amplified again, and finally the picosecond laser is output. The second is to give priority to the generation of a 100-picosecond pulse width seed source, the pulse width is generally 300ps-500ps, and the energy is 200uJ, and then through three-pass amplification, a high-energy 100-picosecond laser output is achieved. The third is the clipping method, which generates a high-energy nanosecond Q-switched pulse. By cutting off the front and back pulse widths, the pulse width of the laser is narrowed, but some energy is also lost at the same time. However, no matter how the 100-picosecond laser is generated, when the frequency is greater than 5Hz, the thermal lens effect generated by the large energy output is serious. When the laser passes through the light guide arm and acts on the human body, the light spot will be sharply reduced. For example, the light guide arm is set to have a light spot of 10mm, and the actual light spot is only 5mm. While the energy output is fixed, the light spot is halved, and the energy density differs by 4 times, which has a great impact on clinical applications. This phenomenon does not occur at low repetition rates (less than 5Hz). Summary of the invention

[0004] The technical problem to be solved by the present invention is: to overcome the disadvantages of the above-mentioned technology and to provide a 100-picosecond laser which can effectively solve the problem of spot size consistency at different frequencies.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is: a hundred-picosecond laser capable of compensating for light spots under high repetition rate, comprising: a seed source, an amplifying crystal, a driver, a reflector, a compensation lens and a light guide arm transmission system; The seed source can generate a laser with a pulse width of 300ps, a repetition frequency of 1-10Hz, an energy of 200uJ, and a wavelength of 1064nm; the laser generated by the seed source is amplified by the amplifying crystal to a laser with an energy of 500mJ and a wavelength of 1064nm; the laser amplified by the amplifying crystal is reflected by the reflector to the light guide arm transmission system; The compensation lens is driven by the driver and can be connected to or leave the optical path between the amplifying crystal and the reflecting mirror.

[0006] The above solution is further improved in that: the compensation lens is a plano-concave lens with a diameter of 25.4 mm and a focal length of f=-1000 mm; and the compensation lens is coated with a 1064 nm anti-reflection film.

[0007] A further improvement of the above scheme is that the amplifying crystal includes a xenon lamp and two Nd:YAG crystals, which are combined through a plurality of lenses to form a three-pass amplifying structure.

[0008] A further improvement of the above solution is that the reflector is a 45-degree reflector.

[0009] A further improvement of the above scheme is that the driver is controlled by a control system. When the operating frequency of the 100-picosecond laser is 1-5 Hz, the control system controls the driver to drive the compensation lens to leave the optical path between the magnifying crystal and the reflector. When the operating frequency of the 100-picosecond laser is 6-10 Hz, the control system controls the driver to drive the compensation lens to connect to the optical path between the magnifying crystal and the reflector.

[0010] A further improvement of the above solution is that the driver is a stepping motor.

[0011] The 100-picosecond laser that can compensate for the spot at high repetition rate provided by the present invention can effectively solve the problem that the spot size of the laser decreases sharply due to the thermal lens effect at high repetition rate. It ensures that the diameter of the actual spot output of the laser is consistent with the set spot diameter, the energy density is consistent, and precise energy control can make clinical applications safer and more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be further described below in conjunction with the accompanying drawings.

[0013] Figure 1 It is a schematic structural diagram of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0014] The 100-picosecond laser of this embodiment is capable of compensating the spot at high repetition rate, such as Figure 1 As shown, it includes: a seed source 1, an amplifying crystal 2, a driver 3, a 45-degree reflector 4, a compensation lens 5 and a light guide arm transmission system 7.

[0015] The seed source 1 can generate a laser with a pulse width of 300ps, a repetition frequency of 1-10Hz, an energy of 200uJ, and a wavelength of 1064nm; the laser generated by the seed source 1 is amplified by the amplifying crystal 2 to a laser with an energy of 500mJ and a wavelength of 1064nm; the laser amplified by the amplifying crystal 2 passes through a 45-degree reflector 4, is reflected to the light guide arm transmission system 7, and then output to the target position through the light guide arm transmission system 7.

[0016] The compensation lens 5 is driven by a driver 3 , and the driver 3 is controlled by a control system 6 . The driver 3 can drive the compensation lens 5 to enter or leave the optical path between the magnifying crystal 2 and the 45-degree reflector 4 .

[0017] The amplifying crystal is a traditional three-pass amplifying crystal, and its structure generally includes a xenon lamp and two Nd:YAG crystals. A three-pass amplifying structure is formed by combining several suitable lenses to achieve the desired energy output.

[0018] The compensation lens 5 is a plano-concave lens with a diameter of 25.4 mm and a focal length of f=-1000 mm. Since the seed source 1 of this embodiment generates a laser with a wavelength of 1064 nm, the compensation lens 5 is coated with a 1064 nm anti-reflection film.

[0019] Since the thermal lens effect begins to become serious only after the operating frequency of the picosecond laser exceeds 5 Hz, compensation cannot be performed when the operating frequency of the picosecond laser is between 1 and 5 Hz, otherwise the light spot will be too large and the energy density will be insufficient.

[0020] The control system 6 reads the operating frequency of the 100-picosecond laser and controls the driver 3 according to the operating frequency; when the operating frequency of the 100-picosecond laser is 1-5Hz, the control system 6 controls the driver 3 to drive the compensation lens 5 to leave the optical path between the magnifying crystal 2 and the 45-degree reflector 4; when the operating frequency of the 100-picosecond laser is 6-10Hz, the control system 6 controls the driver 3 to drive the compensation lens 5 to connect to the optical path between the magnifying crystal 2 and the 45-degree reflector 4.

[0021] The driver can be a stepper motor, a rotary motor, an electromagnetic push rod, an electrically driven hydraulic push rod, etc., and a functional component that can drive the compensation lens 5 to move between two positions in a controlled manner can be selected according to needs.

[0022] The present invention is not limited to the above embodiments. Any technical solution formed by equivalent replacement falls within the protection scope required by the present invention.

Claims

1. A 100-picosecond laser capable of compensating for light spots at high repetition rates, characterized in that: include: Seed source, amplifying crystal, driver, reflector, compensation lens and light guide arm transmission system; The seed source can generate a laser with a pulse width of 300ps, a repetition frequency of 1-10Hz, an energy of 200uJ, and a wavelength of 1064nm; the laser generated by the seed source is amplified by the amplifying crystal to a laser with an energy of 500mJ and a wavelength of 1064nm; the laser amplified by the amplifying crystal is reflected by the reflector to the light guide arm transmission system; The compensation lens is driven by the driver and can be connected to or leave the optical path between the amplifying crystal and the reflecting mirror.

2. The 100-picosecond laser capable of compensating for the spot at high repetition rate according to claim 1, characterized in that: The compensation lens is a plano-concave lens with a diameter of 25.4 mm and a focal length of f=-1000 mm; the compensation lens is coated with a 1064 nm anti-reflection film.

3. The 100-picosecond laser capable of compensating for light spots at high repetition rates according to claim 1, characterized in that: The amplifying crystal includes a xenon lamp and two Nd:YAG crystals, which are combined through a number of lenses to form a three-pass amplifying structure.

4. The 100-picosecond laser capable of compensating for light spots at high repetition rates according to claim 1, characterized in that: The reflector is a 45-degree reflector.

5. The 100-picosecond laser capable of compensating for light spots at high repetition rates according to claim 1, characterized in that: The driver is controlled by a control system. When the operating frequency of the 100-picosecond laser is 1-5 Hz, the control system controls the driver to drive the compensation lens to leave the optical path between the magnifying crystal and the reflector. When the operating frequency of the 100-picosecond laser is 6-10 Hz, the control system controls the driver to drive the compensation lens to connect to the optical path between the magnifying crystal and the reflector.

6. The 100-picosecond laser capable of compensating for light spots at high repetition rates according to claim 1, characterized in that: The driver is a stepper motor.

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