CN202749673U - Intermediate infrared super-continuum spectrum optical fiber laser device excited by super-continuum spectrum light source - Google Patents

Abstract

The utility model provides a mid-infrared supercontinuum fiber laser excited by a supercontinuum light source, which relates to the technical field of laser optoelectronics, and specifically includes a pulsed fiber laser, a quartz photonic crystal fiber and a chalcogenide glass fiber, wherein the pulsed fiber laser The emitted pulsed laser generates a supercontinuum laser with a wavelength range of 1000~2300nm through a quartz photonic crystal fiber. It is a glass optical fiber that produces mid-infrared supercontinuum laser output with a wavelength of 2000-5000nm. The technical problem to be solved by the utility model is to provide a mid-infrared supercontinuum fiber laser excited by a supercontinuum light source to realize mid-infrared supercontinuum laser output with high power and high coupling efficiency.

Description

Mid-infrared supercontinuum fiber laser excited by supercontinuum source

technical field

The utility model relates to the technical field of laser optoelectronics, in particular to a mid-infrared supercontinuum fiber laser excited by a supercontinuum light source.

Background technique

Usually, the band with a wavelength of 3-25 μm is defined as the mid-infrared band, and the mid-infrared laser with a wavelength of 3-5 μm is more widely used. At present, the methods that can achieve 3~5μm laser output mainly include: optical parametric oscillation method, difference frequency oscillation, quantum cascade laser and gas laser. Using the optical parametric oscillation method to achieve mid-infrared laser output requires the use of ultrashort pulse laser pump sources and nonlinear crystal materials, and the cost is high; using the difference frequency oscillation method can only achieve low-power mid-infrared laser output, and The conversion efficiency is low; the quantum cascade laser structure is relatively simple, the conversion efficiency is relatively high, but the wavelength is not tunable; typical mid-infrared gas lasers include CO gas lasers and CO ₂ gas lasers, but the disadvantage of gas lasers is that they are bulky and difficult to use. convenient.

In view of the characteristics of the above methods for realizing mid-infrared lasers, fiber lasers can be used to generate mid-infrared lasers. Fiber lasers are small in size, light in weight, high in conversion efficiency, convenient and flexible in use, wide in wavelength modulation range, and can output high beam quality and high power. laser. Due to the limitation of mid-infrared materials and doping process level, the commonly used ZBLAN fiber lasers doped with rare earth ions are relatively mature, but most of them are low-power output, and the laser output wavelength is less than 4 μm, which is limited for applications with wavelength requirements greater than 4 μm. .

At present, the use of binary chalcogenide glass material fibers to generate mid-infrared supercontinuum lasers has also been reported, but the excitation source mostly uses Raman fiber lasers or thulium-doped fiber lasers, but the output power of the mid-infrared fiber supercontinuum lasers is basically They are all on the order of milliwatts, the output power is low, and it is impossible to achieve high-power mid-infrared supercontinuum laser output.

Therefore, a technical problem that needs to be solved urgently is: how to propose an effective measure to solve the problems of low output power and low coupling efficiency of existing mid-infrared supercontinuum fiber lasers.

Utility model content

The utility model provides a mid-infrared supercontinuum fiber laser excited by a supercontinuum light source, which is used to solve the problems of low output power and low coupling efficiency of the existing mid-infrared supercontinuum fiber laser, and realize high power and high coupling Efficient mid-infrared supercontinuum laser output.

In order to solve the above technical problems, the utility model provides a mid-infrared supercontinuum fiber laser excited by a supercontinuum light source, including a pulsed fiber laser, a quartz photonic crystal fiber and a chalcogenide glass fiber, wherein the pulsed fiber laser emits The pulsed laser is used to generate a supercontinuum laser with a wavelength range of 1000-2300nm through a quartz photonic crystal fiber. The supercontinuum laser is used as an excitation source to excite a chalcogenide glass fiber to generate a mid-infrared supercontinuum with a wavelength of 2000-5000nm. Laser output.

Further, the mid-infrared supercontinuum fiber laser excited by the supercontinuum light source also includes an amplification stage, and the pulsed laser emitted by the pulsed fiber laser enters the amplification stage and then passes through the quartz photonic crystal fiber to generate ultra-high wavelength range of 1000~2300nm. Continuous Spectrum Laser.

Further, the cavity structure of the pulsed fiber laser includes an F-P cavity, a ring cavity and an 8-shaped mode-locked ring cavity.

Further, the amplification stage is a one-stage or multi-stage amplification structure, and the gain fiber used includes an erbium-doped double-clad fiber, an erbium-ytterbium co-doped double-clad fiber and a ytterbium-doped double-clad fiber.

Further, the amplification stage determines the wavelength of the semiconductor laser excitation source used by itself according to the material of the gain fiber used.

Further, the connection method between the quartz photonic crystal fiber and the chalcogenide glass fiber is direct mechanical butt joint, direct fusion or lens focusing spatial coupling.

Further, when the zero dispersion wavelength of the material dispersion of the chalcogenide glass optical fiber is less than or equal to 2300 nm, the chalcogenide glass optical fiber is an ordinary single-clad single-mode optical fiber.

Further, when the zero dispersion wavelength of the chalcogenide glass optical fiber material dispersion is greater than 2300nm, the chalcogenide glass optical fiber is a tapered structure with a tapered length and a tapered core diameter or a photonic crystal with air holes Fiber structure.

Further, the mid-infrared supercontinuum fiber laser excited by the supercontinuum light source also includes a focusing lens, and the focusing lens focuses and couples the supercontinuum laser to the chalcogenide glass fiber to generate mid-infrared light with a wavelength of 2000-5000nm. Supercontinuum laser output, the focusing lens is coated with anti-reflection coating for 1000-2300nm wavelength laser.

In summary, in the scheme described in the present invention, a supercontinuum laser light source is used to excite the chalcogenide glass fiber to generate a mid-infrared supercontinuum laser, avoiding the use of Raman fiber lasers that cannot reach high power and expensive thulium-doped fiber lasers as excitation sources, Using ordinary ytterbium-doped, erbium-doped or erbium-ytterbium co-doped fibers as gain fibers can achieve high-power laser output; three coupling methods are used to realize the coupling of quartz photonic crystal fiber and chalcogenide glass fiber:, quartz photonic crystal fiber and chalcogenide If the glass optical fiber adopts the direct mechanical butt coupling method, the difficulty of fusion splicing can be reduced, and the process is very simple. If the fusion splicing method is used for the quartz photonic crystal fiber and the chalcogenide glass fiber, the full fiber structure can be realized, which is convenient and flexible to use. Splicing a piece of melting point matching fiber between chalcogenide glass fibers can reduce the fusion loss and improve the coupling efficiency to a certain extent. If the quartz photonic crystal fiber and the chalcogenide glass fiber adopt the lens space coupling method, mid-infrared supercontinuum with high coupling efficiency can be realized. spectrum laser output.

Description of drawings

Fig. 1 is the structural representation of the mid-infrared supercontinuum fiber laser excited by a kind of supercontinuum light source of embodiment 1 of the present utility model;

Fig. 2 is a structural representation of a mid-infrared supercontinuum fiber laser excited by a supercontinuum light source in Embodiment 2 of the utility model;

Fig. 3 is a schematic diagram of the tapered structure of the chalcogenide glass optical fiber described in the specific embodiment of the present invention;

Fig. 4 is a schematic structural view of the photonic crystal fiber with air holes of the chalcogenide glass fiber described in the specific embodiment of the present invention.

Detailed ways

Since chalcogenide glass has high refractive index, high nonlinear characteristics, and has a longer infrared cut-off wavelength (>12μm) and lower phonon energy, the embodiment of the utility model uses chalcogenide glass fiber for mid-infrared In the supercontinuum fiber laser, the laser output with a wavelength of 3~5μm can be achieved with higher power and higher coupling efficiency. Below in conjunction with accompanying drawing and specific embodiment, the utility model is described in further detail.

Example 1:

As shown in FIG. 1 , a mid-infrared supercontinuum fiber laser excited by a supercontinuum light source specifically includes a pulsed fiber laser 1 , a quartz photonic crystal fiber 3 and a chalcogenide glass fiber 4 .

In this embodiment, the laser light with a certain repetition frequency, wavelength and pulse width emitted by the pulsed fiber laser 1 passes through the quartz photonic crystal fiber 3 to generate a supercontinuum output with a wavelength range near the near infrared, and the supercontinuum passes through the chalcogenide glass fiber 4 produce supercontinuum output with longer wavelength.

In this embodiment, the quartz photonic crystal fiber 3 and the chalcogenide glass fiber 4 can be directly mechanically butted or directly welded.

More specifically, for the connection method of direct fusion splicing, a section of melting point matching optical fiber can be fused between the quartz photonic crystal fiber 3 and the chalcogenide glass fiber 4 to reduce the melting point loss and improve the coupling efficiency.

Preferably, when the zero dispersion wavelength of the material dispersion of the chalcogenide glass fiber 4 is less than or equal to 2300nm, the chalcogenide glass fiber 4 is an ordinary single-clad single-mode fiber; and when the zero dispersion wavelength of the material dispersion of the chalcogenide glass fiber 4 is greater than 2300nm , the structure of the chalcogenide glass fiber 4 is a tapered structure with a tapered length and a tapered core diameter as shown in FIG. 3 or a photonic crystal fiber structure with an air hole as shown in FIG. 4 .

More specifically, the wavelength range of the supercontinuum laser generated by the quartz photonic crystal fiber 3 is 1000-2300nm, that is, the wavelength range of the supercontinuum in the near-infrared range in this solution is 1000-2300nm, and the wavelength is more The wavelength of the long supercontinuum is 2000~5000nm.

Example 2:

As shown in FIG. 2 , a mid-infrared supercontinuum fiber laser excited by a supercontinuum light source includes a pulsed fiber laser 1 , an amplification stage 2 , a quartz photonic crystal fiber 3 , a chalcogenide glass fiber 4 and a focusing lens 6 .

In this embodiment, the laser light with a certain repetition frequency, wavelength, and pulse width emitted by the pulsed fiber laser 1 is amplified by the power of the amplifier stage 2, and the amplified laser light passes through the quartz photonic crystal fiber 3 to generate light in the near-infrared wavelength range. The supercontinuum output, the supercontinuum laser is focused and coupled to the chalcogenide glass fiber 4 through the focusing lens 6 to generate a supercontinuum output with a longer wavelength.

Preferably, when the zero dispersion wavelength of the material dispersion of the chalcogenide glass fiber 4 is less than or equal to 2300nm, the chalcogenide glass fiber 4 is an ordinary single-clad single-mode fiber; and when the zero dispersion wavelength of the material dispersion of the chalcogenide glass fiber 4 is greater than 2300nm , the structure of the chalcogenide glass fiber 4 is a tapered structure with a tapered length and a tapered core diameter as shown in FIG. 3 and a photonic crystal fiber structure as shown in FIG. 4 .

For supplementary explanation, in the accompanying drawings, 1. Pulse fiber laser, 2. Amplifying stage, 3. Quartz photonic crystal fiber, 4. Chalcogenide glass fiber, 5. Output laser, 6. Focusing lens.

In this solution, pulsed fiber laser 1 selects pulsed fiber lasers with different cavity structures according to the wavelength and power requirements of the output supercontinuum. The cavity structure includes F-P cavity, ring cavity and 8-shaped mode-locked ring cavity.

At the same time, the amplification stage 2 selects a one-stage or multi-stage amplification structure according to the wavelength and power of the supercontinuum to be output. The gain fibers used include erbium-doped double-clad fibers, erbium-ytterbium co-doped double-clad fibers, and erbium-doped double-clad fibers. Ytterbium double-clad fiber.

Specifically, the amplifier stage 2 is different according to the gain fiber used by itself, and the wavelength of the excitation source of the semiconductor laser used by the amplifier stage is also different.

Wherein, the connection mode between the quartz photonic crystal fiber 3 and the chalcogenide glass fiber 4 is direct fusion or spatial coupling. More specifically, the chalcogenide glass fiber 4 is a tapered structure provided with a tapered region length and a tapered region core diameter, or a photonic crystal fiber structure provided with air holes as shown in FIG. 4 .

At the same time, the focusing lens 6 can be coated with an anti-reflection coating for 1000-2300nm wavelength laser to improve the coupling efficiency.

The mid-infrared supercontinuum fiber laser excited by the supercontinuum light source provided by the utility model can realize the generation of high-power near-infrared ultra- Continuous spectrum laser, using this high-power supercontinuum laser as an excitation source to excite chalcogenide glass fiber can realize high-power (tens of watts) supercontinuum laser in the mid-infrared band. In addition, the coupling efficiency of the mid-infrared supercontinuum fiber laser using the focusing lens in the optical path provided by the utility model is much higher than that of the existing all-fiber mid-infrared supercontinuum fiber laser, which has great practicability.

The mid-infrared supercontinuum fiber laser excited by the supercontinuum light source provided by the utility model has been introduced in detail above. In this paper, specific examples have been used to illustrate the principle and implementation of the utility model. The description of the above examples is only It is used to help understand the method of the utility model and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the utility model, there will be changes in the specific implementation and scope of application. In summary , the content of this specification should not be interpreted as a limitation of the present utility model.

Claims (9)

1. Super continuum source excitation in infrared optical fiber laser with super continuous spectrum, it is characterized in that, comprise pulse optical fiber, quartzy photonic crystal fiber and chalcogenide glass fiber, wherein, the pulse laser that described pulse optical fiber sends, producing wave-length coverage by quartzy photonic crystal fiber is the super continuous spectrums laser of 1000 ~ 2300nm, described super continuous spectrums laser is as driving source, the excitation chalcogenide glass fiber, producing wavelength is the middle infrared excess continuous spectrum Laser output of 2000 ~ 5000nm.
2. Super continuum source according to claim 1 excitation in infrared optical fiber laser with super continuous spectrum, it is characterized in that, also comprise amplifying stage, the pulse laser that pulse optical fiber sends is the super continuous spectrums laser of 1000 ~ 2300nm by quartzy photonic crystal fiber generation wave-length coverage again after entering amplifying stage.
3. Super continuum source according to claim 1 excitation in infrared optical fiber laser with super continuous spectrum, it is characterized in that, the cavity structure of described pulse optical fiber comprises F-P chamber, annular chamber and 8 letter lock mould annular chambers.
4. Super continuum source according to claim 2 excitation in infrared optical fiber laser with super continuous spectrum, it is characterized in that, described amplifying stage is one or more levels structure for amplifying, and the gain fibre that adopts comprises doubly clad optical fiber, the erbium ytterbium co doped double clad fiber of er-doped and mixes the doubly clad optical fiber of ytterbium.
5. Super continuum source according to claim 4 excitation in infrared optical fiber laser with super continuous spectrum, it is characterized in that the wavelength of the semiconductor laser driving source that described amplifying stage adopts according to the material decision self of employing gain fibre.
6. Super continuum source according to claim 1 excitation in infrared optical fiber laser with super continuous spectrum, it is characterized in that, the connected mode of described quartzy photonic crystal fiber and chalcogenide glass fiber is direct mechanical docking, direct welding or lens focus spatial coupling.
7. Super continuum source according to claim 1 excitation in infrared optical fiber laser with super continuous spectrum, it is characterized in that, when the zero-dispersion wavelength of described chalcogenide glass fiber material dispersion during less than or equal to 2300nm, described chalcogenide glass fiber is common single covering monomode fiber.
8. Super continuum source according to claim 1 excitation in infrared optical fiber laser with super continuous spectrum, it is characterized in that, when the zero-dispersion wavelength of described chalcogenide glass fiber material dispersion during greater than 2300nm, described chalcogenide glass fiber is to be provided with the pyramidal structure of cone section length and cone district core diameter or to be the photonic crystals optical fiber structure with airport.
9. Super continuum source according to claim 1 excitation in infrared optical fiber laser with super continuous spectrum, it is characterized in that, also comprise condenser lens, described condenser lens focuses on super continuous spectrums laser and is coupled to chalcogenide glass fiber to produce wavelength be the middle infrared excess continuous spectrum Laser output of 2000 ~ 5000nm, and described condenser lens plating is to the anti-reflection film of 1000-2300nm wavelength laser.

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