CN207588207U - A kind of beam quality reforming unit - Google Patents

Abstract

The utility model discloses a kind of beam quality reforming unit, device includes：Semiconductor laser；Disc laser；Mix ytterbium silica fibre three parts composition.The utility model utilizes beam quality M²The semiconductor laser of ＜ 200 carries out end pumping to more stroke disc lasers, obtains continuous multimode, the output of bloom light conversion efficiency laser, M²＜ 50.Using the laser that disc laser exports as diode pumping source, carried out to mixing ytterbium silica fibre with band pumping, obtaining has low Excited state (2%), bloom phototranstormation efficiency, nearly diffraction limit (M²＜ 2) laser output.The high efficiency of semiconductor laser, the high efficiency and heat radiation of disc laser and the same low Excited state characteristic that the output of ytterbium silica fibre is mixed with pumping is cleverly utilized in the utility model, realizes high power, the method for transformation of high light beam quality.

Description

A light beam quality conversion device

technical field

The utility model relates to the field of all-solid-state lasers, in particular to the field of a light beam quality conversion device.

Background technique

Since the Yb ³⁺ doped laser medium is usually limited by severe thermal effects, the development of all-solid-state lasers with high power, high beam quality, and high conversion efficiency is slow. Nowadays, with the emergence of in-band pumping technology, Yb:YAG lasers based on the in-band pumping of semiconductor lasers and disk lasers are becoming a research hotspot for obtaining all-solid-state lasers with high power, high beam quality, and high conversion efficiency. The concentration of Yb:YAG doped with Yb ³⁺ can reach 20%. By pumping with 940nm wavelength pump light, YAG:YAG crystal can emit two main laser wavelengths with central wavelengths of 1050nm and 1030nm. By using the high-efficiency heat dissipation of the disk laser, the heat of the all-solid-state laser can be shared, and a very small amount of heat can be brought to the ytterbium-doped silica fiber pumped with the same band, so as to achieve a simultaneous laser with low quantum deficit (within 2%) It is equipped with a pump laser and obtains a high-power near-diffraction-limited M ² <2 laser output.

Utility model content

The purpose of this utility model is to provide a beam quality conversion device, which uses semiconductor lasers and disk lasers as primary and secondary pumping sources, and pumps Yb ³⁺ doped fiber gain media with the same belt, and its quantum efficiency is extremely high. The beam quality is close to the laser output of the diffraction limit, and it can solve the thermal effect problem well, and the output laser is a single-mode laser output by the fiber.

Said semiconductor laser adopts gallium arsenide laser with center wavelength of 940nm and 969nm as the primary pumping source.

A beam quality conversion device, including a semiconductor laser, a disk laser, and an ytterbium-doped silica fiber; the semiconductor laser is used as a primary pumping source, and the pumping laser enters the disk laser to pump the disk laser to obtain a high-light (above 70%) multi-mode laser output with conversion efficiency; use the laser output from the disk laser as a secondary pump source to pump the ytterbium-doped silica fiber in the same band (quantum deficit <2%), and pass the ytterbium-doped silica fiber After the output, a conversion device with high beam quality (M ² <2) is realized.

The said disk laser adopts 24, 32, 48 stroke disk lasers as the secondary pumping source. The gain medium is Yb:YAG; the output laser of the disk laser is a multimode laser, and its output wavelength is 1030nm and 1050nm;

In the ytterbium-doped silica fiber, the gain medium is Yb ³⁺ , the doped matrix is silicon dioxide, and the output wavelength of the laser after secondary pumping is 1080 nm; the fiber gain medium Yb ³⁺ is doped at a molar concentration of 15 -20%.

The beam quality of the first-stage semiconductor pumping source M ² <200, the beam quality of the second-stage pumping disk laser M ² <50, and the finally obtained ytterbium-doped silica fiber can obtain a high beam quality of M ² <2 laser output.

The utility model provides a light beam quality conversion device, which adopts a modular design, has a simple structure and is easy to maintain.

Description of drawings

Fig. 1 is a kind of beam quality transformation device of embodiment 1

Detailed ways

In order to make the purpose and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model. The specific embodiment is explained with a beam quality conversion device and method.

As shown in FIG. 1 , a beam quality conversion device includes a semiconductor laser 1 , a disk laser 3 , and an ytterbium-doped silica fiber 5 . It is characterized in that: the semiconductor laser 1 is used as a primary pump source to pump 2 the disk laser 3 to obtain a multi-mode laser output with high light-to-light (70%) conversion efficiency; the laser output by the disk laser 3 is used as The secondary pump source pumps the ytterbium-doped silica fiber in-band 4 (quantum deficit<2%), realizing a conversion device with high beam quality (M2<2).

Said semiconductor laser 1 uses gallium arsenide lasers with center wavelengths of 940nm and 969nm as the first-stage pumping source, and its array or single-tube form.

The disk laser 3 uses 24, 32, 48 stroke disk lasers 3 as the secondary pumping source. The gain medium is Yb:YAG; the output laser of the disk laser 3 is a multimode laser, and its output wavelength is 1030nm and 1050nm;

The disk laser 3 mainly includes: a reflective prism and an aspheric reflective focusing mirror, wherein the reflective prism is used to deflect the pump light to achieve the purpose of multi-stroke pumping the disk crystal. The aspherical reflective focusing mirror is a reflective element that utilizes the characteristics of how parallel light reaches its reflective surface and then focuses on the focal point.

The gain medium of the ytterbium-doped silica fiber 5 is Yb3+, the doped matrix is silicon dioxide, and the output wavelength of the laser after secondary pumping is 1080nm; the Yb3+ doping concentration of the fiber gain medium is 15-20%, the same The pump range can obtain extremely high light-to-light conversion efficiency, the theoretical light-to-light conversion efficiency can reach 98%, and the light-to-light conversion efficiency of the system can reach more than 70%, which is an important link to realize the beam quality conversion. Due to its high quantum efficiency of 98% and only 2% quantum deficit, it can output ultra-high power lasers while generating very little heat. This heat is dissipated by utilizing micro-channel cooling technology.

The beam quality conversion device and method, the beam quality M2<200 of the first-stage semiconductor pump source 1, the beam quality M2<50 of the second-stage pumping disk laser 3, and finally the ytterbium-doped The quartz optical fiber 5 can obtain high beam quality laser output with beam quality M2<2.

In the device, the 1030nm co-band pumping disk laser 3 is used as the co-band pumping source of the 1050nm ytterbium-doped silica fiber 5, coupled into the ytterbium-doped silica fiber 5 through a fiber wavelength division multiplexer, and the ground state energy level absorbs the 1030nm pumping source. Transition from the energy level 2F7/2 to the higher energy level 2F5/2, and from the excited state 2F5/2 to 2F7/2, will generate photons at 1050nm in this quasi-three-level structure. The generation of 1050nm laser is achieved by using a very short length of highly doped ytterbium-doped fiber and a narrow-band fiber Bragg grating. Since the laser longitudinal mode spacing is related to the laser cavity length, reducing the laser cavity length can increase the laser longitudinal mode spacing. , which is conducive to the selection of single longitudinal mode, and the narrow-band fiber Bragg grating can further limit the wavelength range of the output laser, and finally obtain a single-frequency laser output with a narrow linewidth of 1050nm.

The above is only a preferred embodiment of the utility model, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made, these improvements and Retouching should also be regarded as the scope of protection of the present utility model.

Claims (3)

1. a kind of beam quality reforming unit, it is characterised in that：Including semiconductor laser（1）, disc laser（3）, mix ytterbium Silica fibre（5）Composition；Semiconductor laser enters disc laser to disk laser as the pumping laser of level-one pumping source Device is pumped, and is obtained the multi-mode laser with 70% transformation efficiency of bloom-light and is exported；Utilize disc laser（3）Output swashs Light, as diode pumping source to mixing ytterbium silica fibre（5）It carries out with band pumping, Excited state ＜ 2%, through mixing ytterbium silica fibre（5） After export, realize high light beam quality M²The reforming unit of ＜ 2.

2. a kind of beam quality reforming unit according to claim 1, it is characterised in that：Semiconductor laser（1）Using Centre wavelength is 940nm and/or 969nm gallium arsenide lasers as level-one pumping source.

3. a kind of beam quality reforming unit according to claim 1, it is characterised in that：Disc laser（3）Using 24, 32 or 48 stroke disc lasers（3）As diode pumping source, gain media Yb:YAG；Disc laser（3）Export laser Device is multi-mode laser, output center wavelength 1030nm, 1050nm.