CN102545014A - Method for double-pulse laser with wavelengths of 1.0mu m and 1.3mu m - Google Patents

Abstract

The invention belongs to the technical field of physics laser and relates to a method for two all solid-state pulse laser with the wavelength of 1.0mu m and 1.3mu m. The used double-pulse laser with the wavelengths of 1.0mu m and 1.3mu m comprises a pumping source, an optical fiber, a coupling system, a laser gain crystal, an endoscope for coating the double wavelengths of 1.0mu m and 1.3mu m, and two optical switches, wherein the endoscope comprises an input mirror, a turning mirror and two output mirrors to form a composite laser cavity of the laser. The method comprises the following steps of: making the laser generated by the pumping source pass through the optical fiber, the coupling system and the input mirror in turn so as to pump the laser gain crystal; modulating laser with the wavelengths of 1.0mu m and 1.3mu m through the two optical switches, and establishing laser oscillation of 1.0mu m and 1.3mu m; and outputting pulse laser with the wavelengths of 1.0mu m and 1.3mu m through the two output mirrors respectively. Optical switching devices for the wavelengths of 1.0mu m and 1.3mu m are readily available, and the laser has the advantages of compact structure, small volume, low manufacturing cost, high efficiency and high stability.

Description

A double-pulse laser method with a wavelength of 1.0μm/1.3μm

Technical field:

The invention belongs to the technical field of physical lasers, and relates to a double-pulse laser system, in particular to a method of two all-solid-state pulsed lasers with a wavelength of 1.0 μm/1.3 μm.

Background technique:

A double pulse laser is a device capable of outputting two wavelengths of pulsed lasers. Its main feature is to excite two radiation lines of the laser crystal. A set of laser devices is used to realize two wavelengths of laser oscillation and output two wavelengths of pulsed lasers. At present, the research and patented technology of dual-wavelength pulsed lasers are all focused on improving the time and space coincidence of the two wavelengths of laser light. When two radiation lines overlap in time and space, there will be The competition of the two modes leads to the instability of the laser output power, or the problem that the radiation of one of the spectral lines is suppressed. For some applications, such as sum frequency, the pulse coincidence of the two wavelengths is necessary; while for some applications, the spatial or temporal coincidence of the two pulses is not required, such as: dual wavelength for PDT (photodynamic therapy) Laser does not need the coincidence of two pulses at all, but it puts forward higher requirements for output power and power stability. Most of the dual-wavelength pulse lasers currently on the market use two laser crystals and two sets of laser devices to obtain different wavelengths by switching between the two lasers, or double-pulse lasers based on fundamental frequency and frequency doubling; These devices that use dual sets of lasers to generate dual wavelengths are inconvenient to use, complex in assembly structure, and poor in laser alignment.

Invention content:

The purpose of the present invention is to overcome the shortcomings of the prior art, seek to design a double pulse laser system and method, adopt a laser crystal and a set of lasers, respectively excite two radiation lines of the crystal, so that the 1.0 μm laser pulse and 1.3 The μm laser pulses are completely non-coincident in space and time, which eliminates the instability of output power caused by mode competition, making it promising in medical treatment, cosmetology and industry.

In order to achieve the above-mentioned purpose, the double-pulse laser with a wavelength of 1.0 μm/1.3 μm used in the present invention includes a pump source, an optical fiber, a coupling system, a laser gain crystal, a cavity mirror coated with a dual-wavelength coating of 1.0 μm/1.3 μm, and two optical Switch, the cavity mirror includes an input mirror, a turning mirror and two output mirrors and constitutes a laser composite laser cavity; firstly, the laser generated by the pump source is pumped through the optical fiber, the coupling system and the input mirror to pump the laser gain crystal, and then through the two Each optical switch modulates the 1.0μm and 1.3μm lasers respectively, establishes 1.0μm and 1.3μm laser oscillations in the composite laser cavity, and then outputs 1.0μm and 1.3μm pulsed lasers respectively from two output mirrors.

The laser gain crystals involved in the present invention include Nd:YVO ₄ , Nd:YAG, Nd:GdVO ₄ , Nd:YLF, Nd:YAP, and other laser crystals with two radiation lines of 1.0 μm and 1.3 μm.

The input mirror and the output mirror of the present invention are the input end and two output ends of the composite laser cavity respectively, and the turning mirror is arranged between the laser gain crystal and the optical switch to form the composite laser cavity, so that the laser cavity of two wavelengths is relatively independent.

The two optical switches in the present invention are respectively aimed at 1.0 μm laser and 1.3 μm laser, the laser pulse is formed in the off signal of the optical switch, and the time interval between the adjacent off signals of the two optical switches is equal to the laser gain crystal The lifetime of the upper energy level can eliminate the mode competition of the 1.0μm and 1.3μm lasers in the crystal, improve the stability of the laser, and at the same time accumulate the number of upper energy level inversion particles of 1.0μm and 1.3μm, and improve the efficiency of the laser.

The present invention uses rare earth ion-doped laser gain crystals, aiming at 1.0 μm and 1.3 μm dual-wavelength cavity mirror coating technology, its 1.0 μm and 1.3 μm optical switch devices are easy to obtain, and the laser has compact structure, small volume, low cost, high efficiency and stability Good sex.

Description of drawings:

FIG. 1 is a schematic diagram of the structure and principle of the laser device used in the present invention.

Fig. 2 is a schematic diagram of the principles of the off signals of two optical switches of the present invention.

Detailed ways:

Further description will be given below through the embodiments and in conjunction with the accompanying drawings.

The laser used in this embodiment includes a pump source 1, an optical fiber 2, a coupling system 3, an input mirror 4, a laser gain crystal 5, a turning mirror 6, an optical switch 7, an output mirror 8, an optical switch 9 and an output mirror 10, wherein The input mirror 4, the turning mirror 6, the output mirror 8 and 10 form a composite laser cavity, and the light source generated by the pump source 1 passes through the optical fiber 2, the coupling system 3, and the input mirror 4 to pump the laser gain crystal 5 to excite the laser gain crystal 5. Stimulated radiation of the two spectral lines of 1.0 μm and 1.3 μm, the optical switches 7 and 9 modulate the lasers of the two wavelengths respectively, and the 1.0 μm and 1.3 μm laser oscillations are established in the composite laser cavity, and the output mirrors 8 and 10 1.0 μm and 1.3 μm pulsed lasers are respectively output; the time intervals t1 and t3 between adjacent off signals of the optical switches 7 and 9 are both equal to the upper energy level lifetime of the laser gain crystal.

The laser crystal used in this embodiment has crystals with two radiation lines of 1.0 μm and 1.3 μm; the time interval t1 and t3 of adjacent off signals of two optical switches can be determined according to the crystal; the curvature of each cavity mirror and the laser cavity The total length is changed according to the actual situation; the 1.0 μm laser and the 1.3 μm laser are respectively output by the output mirror 8 and the output mirror 10, which can be arbitrarily selected according to actual needs, only need to change the coating parameters of the turning mirror 6, output mirrors 8 and 10, and In this way, the positions of the optical switches 7 and 9 can be determined.

Example 1:

This embodiment 1 relates to a 1.064 μm/1.342 μm double-pulse laser method with the same repetition frequency. The repetition frequency of the two lasers is 5 kHz. The pump source 1 is a diode laser with an output of 808 nm. Through the optical fiber 2, the coupling system 3 and The input mirror 4 pumps the laser gain crystal 5, the laser gain crystal 5 is Nd:YVO ₄ crystal, the input mirror 4 is highly reflective to 1.06 μm and 1.34 μm lasers, and the turning mirror 6 is highly reflective to 1.06 μm and highly transparent to 1.34 μm laser , the repetition frequency of the off signal of the optical switch 7 to the 1.34 μm laser is 5 kHz, the output mirror 8 has high transmission to the 1.06 μm laser and the transmittance to the 1.34 μm laser is 5%, the repetition frequency of the off signal of the optical switch 9 to the 1.06 μm laser 5kHz, output mirror 10 has 10% transmittance to 1.06 μm, the off signal interval t1=t3=98 μs of optical switches 7 and 9, the 1.34 μm pulse laser with repetition frequency 5kHz is obtained by output mirror 8, and the repetition frequency is obtained by output mirror 10 1.06μm pulsed laser at 5kHz.

According to the 1.0 μm/1.3 μm double-pulse laser with the same repetition rate involved in Example 1, the laser gain crystal 5 or choose Nd:YAG, Nd:GdVO ₄ , or another laser gain crystal with these two spectral lines, and an optical switch 7 The turn-off signal intervals t1 and t3 of 9 and 9 are determined according to the laser gain crystal.

Example 2:

This embodiment relates to a 1.047 μm/1.321 μm double-pulse laser method with different repetition frequencies, the repetition frequency of the 1.047 μm laser is 500 Hz, and the repetition frequency of the 1.321 μm laser is 1000 Hz; , the coupling system 3 and the input mirror 4 pump the laser gain crystal 5, the laser gain crystal 5 is a-cut-Nd:YLF crystal, the input mirror 4 is highly reflective to 1.047 μm and 1.321 μm lasers, and the turning mirror 6 is 1.047 μm high Reflection and high transmittance to 1.321μm laser, optical switch 7 to 1.321μm laser off signal repetition frequency 1000Hz, output mirror 8 to 1.047μm high transmittance and 1.321μm laser transmittance 3%, optical switch 9 to 1.047μm The repetition frequency of the off signal of the laser is 500Hz, the output mirror 10 has a 5% transmittance to 1.047 μm, the interval between the off signals of the optical switches 7 and 9 is t1=t3=0.5ms, t2=1ms, and the repetition frequency 1000Hz is obtained by the output mirror 8 The 1.321 μm pulsed laser light is obtained from the output mirror 10 to obtain the 1.047 μm pulsed laser light with a repetition frequency of 500 Hz.

According to the different repetition frequency 1.0 μm/1.3 μm double-pulse lasers produced in Example 2, the laser gain crystal 5 or the crystal with 1.0 μm/1.3 μm spectral lines, the repetition frequency of the two kinds of lasers depends on the actual needs and the laser crystal used. OK, correspondingly t1, t2, t3 also change.

According to the 1.0 μm/1.3 μm double-pulse laser involved in Embodiments 1 and 2, or adopt the side-pumped mode, both lasers are output by the input mirror 4, as long as the coating parameters of the cavity mirrors 4, 8 and 10 are changed accordingly. Can.

According to the 1.0 μm/1.3 μm double-pulse lasers involved in Embodiments 1 and 2, frequency conversion crystals are added inside or outside the laser cavity to obtain pulsed lasers with more wavelengths.

According to the double-pulse lasers involved in Embodiments 1 and 2, it is used to realize double-pulse lasers of other wavelengths, as long as the device is replaced and the parameters are changed accordingly according to the wavelength.

Claims (4)

1. double-pulse laser method that wavelength is 1.0 μ m/1.3 μ m; The wavelength that uses be the double-pulse laser device of 1.0 μ m/1.3 μ m comprise pumping source, optical fiber, coupled system, laser gain crystal, to chamber mirror and two optical switches of 1.0 μ m/1.3 μ m dual wavelength plated films, the chamber mirror comprises an input mirror, turning mirror and two outgoing mirrors and constitutes the laser composite laser carity; It is characterized in that the laser that pumping source is produced passes through optical fiber, coupled system and input mirror pumping laser gain crystal successively; Respectively the laser of 1.0 μ m and 1.3 μ m is modulated through two optical switches again; In composite laser carity, set up 1.0 μ m and 1.3 μ m laser generations, export the pulse laser of 1.0 μ m and 1.3 μ m then by two outgoing mirrors respectively.

2. wavelength according to claim 1 is the double-pulse laser method of 1.0 μ m/1.3 μ m, it is characterized in that the laser gain crystal that relates to comprises Nd:YVO ₄, Nd:YAG, Nd:GdVO ₄, Nd:YLF and Nd:YAP, or have the laser crystal of 1.0 μ m and two radiation spectral lines of 1.3 μ m.

3. wavelength according to claim 1 is the double-pulse laser method of 1.0 μ m/1.3 μ m; It is characterized in that input mirror and outgoing mirror are respectively input and two outputs of composite laser carity; Turning mirror is arranged between laser gain crystal and the optical switch; Constitute composite laser carity, make the laser cavity of two kinds of wavelength relatively independent.

4. wavelength according to claim 1 is the double-pulse laser method of 1.0 μ m/1.3 μ m; It is characterized in that two optical switches are respectively to 1.0 μ m laser and 1.3 μ m laser; Laser pulse is in the cut-off signals of optical switch, to form; The time interval between the adjacent cut-off signals of two optical switches equals the upper level lifetime of laser gain crystal; To eliminate 1.0 μ m and 1.3 μ m laser in intracrystalline mode competition, improve the stability of laser, make the last energy level inverted population of 1.0 μ m and 1.3 μ m obtain accumulation simultaneously.

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