A laser output lens for radio frequency carbon dioxide laser

Abstract

The present invention discloses a laser output lens for a radio frequency carbon dioxide laser, comprising a lens substrate (1) and a lens coating layer (2) consisting of eight coating layers, wherein the thickness of the first coating layer (21) is 1618-1620 nm, the thickness of the second coating layer (22) is 685-687 nm, the thickness of the third coating layer (23) is 1618-1620 nm, the thickness of the fourth coating layer (24) is 685-687 nm, the thickness of the fifth coating layer (25) is 1618-1620 nm, the thickness of the sixth coating layer (26) is 685-687 nm, the thickness of the seventh coating layer (27) is 1618-1620 nm, and the thickness of the eighth coating layer (28) is 421-423 nm. The lens of the present invention can improve the transmittance of 650 nm red laser without affecting the transmittance of carbon dioxide laser, thereby improving the dimming efficiency of the laser.

Description

Technical Field

[0001] The invention relates to the field of laser technology, in particular to a laser output lens for a radio frequency carbon dioxide laser, which can improve the transmittance of a 650nm wavelength red laser without affecting the transmittance of a carbon dioxide laser, so as to improve the laser dimming efficiency. Background Art

[0002] During the assembly process of the laser, the laser output lens corresponding to the laser output port needs to be adjusted, mainly to adjust the installation angle of the lens. The adjustment method is as follows: (1) A semiconductor laser is set at a position corresponding to the laser output lens outside the laser resonant cavity of the carbon dioxide laser. The semiconductor laser can output a red light beam with a wavelength of 650nm and an output laser power of 100mW; (2) A piece of white paper is set vertically between the carbon dioxide laser and the semiconductor laser, and the semiconductor laser is turned on to output a beam of red laser. The laser beam first penetrates the white paper, leaving a light spot 1 on the paper, and then enters the laser resonant cavity through the laser output mirror corresponding to the position of the laser output port of the carbon dioxide laser. The red laser beam continues to transmit along the optical path inside the resonant cavity, and is reflected by the laser resonant cavity and each laser reflector, and finally output by the laser output mirror and projected onto the white paper to form a light spot 2. The dimming process is to continuously adjust the angle of the laser output mirror on the laser resonant cavity until the light spot 1 coincides with the light spot 2.

[0003] However, in the actual dimming process, the second light spot is very weak and almost invisible, and the dimming efficiency is very low. There are two main reasons for this problem: (1) The laser power output by the semiconductor laser is relatively small, because too much power will endanger the safety of the dimming staff; (2) The transmittance of the laser output mirror to the red laser with a wavelength of 650nm is less than 3%. After the 100mW laser beam is incident on the resonant cavity through the laser output mirror, the power drops to 3mW. There is also loss when the laser beam passes through the laser output mirror. The actual red laser power reaching the resonant cavity is less than 3mW. In the process of reflection through the three laser reflectors inside the resonant cavity, there will be loss again. Finally, when the reflected light beam is output through the laser output mirror and projected onto the white paper to form the second light spot, the power of the laser beam will drop below 1mW. At this time, the second light spot projected onto the white paper is very weak and almost invisible.

[0004] The reason for the above result is that when designing the film structure of the existing laser output mirror, the transmittance of the laser output mirror to the red laser with a wavelength of 650nm is not considered, because the main function of the laser output mirror is to output the carbon dioxide laser inside the resonant cavity to the outside of the resonant cavity at a certain transmittance. The wavelength of the carbon dioxide laser is between 9300nm and 10600nm. When designing the film structure of the lens, the main consideration is the laser transmittance in this band. As long as the laser transmittance in this band meets the design requirements, the performance of the laser can be met. In the previous design of the film structure of the laser output lens, the laser transmittance with a wavelength of 650nm was not considered at all.

[0005] In order to solve the existing problems, lens engineers began to pay attention to the transmittance of the laser output mirror of the CO2 laser to the 650nm red laser. The main problem encountered in the design process is that when the transmittance of the 650nm red laser is improved through the film layer structure design, the transmittance of the CO2 laser will also fluctuate and deviate from the ideal transmittance index, which will adversely affect the performance of the CO2 laser. Therefore, it is necessary to design a film layer structure for the laser output mirror to improve the transmittance of the 650nm wavelength red laser without affecting the transmittance of the CO2 laser. Summary of the invention

[0006] The purpose of the present invention is to provide a laser output lens for a radio frequency carbon dioxide laser, which can improve the transmittance of a red laser with a wavelength of 650nm without affecting the transmittance of a carbon dioxide laser, so as to improve the laser dimming efficiency, in view of the problems existing in the prior art.

[0007] The purpose of the present invention is to be solved by the following technical solutions:

[0008] A laser output lens for a radio frequency carbon dioxide laser, the laser output lens comprising a lens substrate made of zinc selenide and a lens coating layer, the lens coating layer being sequentially arranged on the lens substrate and comprising a first coating layer made of yttrium fluoride, a second coating layer made of zinc selenide, a third coating layer made of yttrium fluoride, a fourth coating layer made of zinc selenide, a fifth coating layer made of yttrium fluoride, a sixth coating layer made of zinc selenide, a seventh coating layer made of yttrium fluoride and an eighth coating layer made of zinc selenide, wherein the thickness of the first coating layer is The thickness of the lens coating layer is 1618nm-1620nm, the thickness of the second coating layer is 685nm-687nm, the thickness of the third coating layer is 1618nm-1620nm, the thickness of the fourth coating layer is 685nm-687nm, the thickness of the fifth coating layer is 1618nm-1620nm, the thickness of the sixth coating layer is 685nm-687nm, the thickness of the seventh coating layer is 1618nm-1620nm, and the thickness of the eighth coating layer is 421nm-423nm, so that the total thickness of the lens coating layer is 8948nm-8964nm.

[0009] The transmittance of the laser output lens composed of the lens coating layer and the lens substrate to the red laser with a wavelength of 650nm is not less than 40%.

[0010] The transmittance of the laser output lens composed of the lens coating layer and the lens substrate to the red laser with a wavelength of 650nm is 45% to 55%.

[0011] The transmittance of the laser output lens composed of the lens coating layer and the lens substrate to the red laser with a wavelength of 650nm is 48% to 55%.

[0012] The transmittance of the laser output lens composed of the lens coating layer and the lens substrate to the carbon dioxide laser with a wavelength of 9300nm is not less than 20%.

[0013] The transmittance of the laser output lens composed of the lens coating layer and the lens substrate to the carbon dioxide laser with a wavelength of 9300nm is 21% to 23%.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] The laser output lens of the present invention can improve the transmittance of red laser with a wavelength of 650nm without affecting the transmittance of carbon dioxide laser. When used, it can improve the dimming efficiency of the laser, so it is suitable for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 It is a schematic structural diagram of a laser output lens for a radio frequency carbon dioxide laser of the present invention;

[0017] Attached Figure 2 It is a partial enlarged schematic diagram of the lens coating layer of the laser output lens of the present invention;

[0018] Attached Figure 3 It is a transmittance curve diagram of the laser output lens in the prior art to the laser in the visible light band;

[0019] Attached Figure 4 It is a transmittance curve diagram of the laser output lens of the present invention to the laser in the visible light band;

[0020] Attached Figure 5 The figure is a comparison chart of the transmittance curves of the laser output lens in the prior art and the laser output lens of the present invention to the far-infrared band laser.

[0021] Among them: 1—lens substrate; 2—lens coating layer; 21—first coating layer; 22—second coating layer; 23—third coating layer; 24—fourth coating layer; 25—fifth coating layer; 26—sixth coating layer; 27—seventh coating layer; 28—eighth coating layer. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] like Figure 1-2 As shown: a laser output lens for a radio frequency carbon dioxide laser, the laser output lens comprises a lens substrate 1 made of zinc selenide and a lens coating layer 2, the lens coating layer 2 is composed of a first coating layer 21 made of yttrium fluoride, a second coating layer 22 made of zinc selenide, a third coating layer 23 made of yttrium fluoride, a fourth coating layer 24 made of zinc selenide, a fifth coating layer 25 made of yttrium fluoride, a sixth coating layer 26 made of zinc selenide, a seventh coating layer 27 made of yttrium fluoride and an eighth coating layer 28 made of zinc selenide, which are sequentially arranged on the lens substrate 1, wherein the first coating layer 21 The thickness of the first coating layer 22 is 1618nm-1620nm, the thickness of the second coating layer 22 is 685nm-687nm, the thickness of the third coating layer 23 is 1618nm-1620nm, the thickness of the fourth coating layer 24 is 685nm-687nm, the thickness of the fifth coating layer 25 is 1618nm-1620nm, the thickness of the sixth coating layer 26 is 685nm-687nm, the thickness of the seventh coating layer 27 is 1618nm-1620nm, and the thickness of the eighth coating layer 28 is 421nm-423nm, so that the total thickness of the lens coating layer 2 is 8948nm-8964nm.

[0024] When in use, the transmittance of the laser output lens composed of the lens coating layer 2 and the lens substrate 1 to the red laser with a wavelength of 650nm is 48% to 55%. And the transmittance of the laser output lens composed of the lens coating layer 2 and the lens substrate 1 to the carbon dioxide laser with a wavelength of 9300nm is not less than 20%; further defined as: the transmittance of the laser output lens composed of the lens coating layer 2 and the lens substrate 1 to the carbon dioxide laser with a wavelength of 9300nm is 21% to 23%.

[0025] The reason for using a 650nm red laser for dimming is that the CO2 laser is invisible, so it cannot be used directly to calibrate the installation angle of the laser output mirror. A visible light must be used to indicate the path of laser transmission. Therefore, a red light beam is used to simulate the transmission path of the CO2 laser and adjust the installation angle of the laser output mirror to the optimal position.

[0026] The laser output lens for a radio frequency carbon dioxide laser provided by the present invention is further described below through comparative examples and embodiments.

[0027] Comparative Example

[0028] The structure of the existing laser output lens for RF CO2 laser is shown in Table 1.

[0029] Table 1

[0030] Lens structure Material thickness Eighth coating layer Zinc Selenide ZnSe 430nm-432nm Seventh coating layer <![CDATA[Yttrium fluoride YF3]]> 1453nm-1455nm Sixth coating layer Zinc Selenide ZnSe 808nm-810nm Fifth coating layer <![CDATA[Yttrium fluoride YF3]]> 1453nm-1455nm Fourth coating layer Zinc Selenide ZnSe 808nm-810nm The third coating layer <![CDATA[Yttrium fluoride YF3]]> 1453nm-1455nm Second coating layer Zinc Selenide ZnSe 808nm-810nm First coating layer <![CDATA[Yttrium fluoride YF3]]> 1453nm-1455nm Lens substrate Zinc Selenide ZnSe 4mm-5mm

[0031] The lens substrate is coated with a coating machine according to the film structure designed in Table 1. The film data on the laser output lens obtained are shown in Table 2.

[0032] Table 2

[0033] Film 1 2 3 4 5 6 7 8 Material <![CDATA[YF3]]> ZnSe <![CDATA[YF3]]> ZnSe <![CDATA[YF3]]> ZnSe <![CDATA[YF3]]> ZnSe Physical thickness (nm) 1454.08 808.97 1454.08 808.97 1454.08 808.97 1454.08 431.45 Optimize No Yes Yes Yes Yes Yes Yes Yes Yes Group 1 1 1 1 1 1 1 1 Constraint No No No No No No No No No Minimum thickness 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm Maximum thickness 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm Allow pin insertion? Yes Yes Yes Yes Yes Yes Yes Yes

[0034] The laser output lens with the film structure shown in Table 2 was tested using a transmittance tester to obtain a transmittance curve of the laser output lens in the prior art for visible light band lasers. Figure 3 As shown, the transmittance to red laser with a wavelength of 650nm is less than 3%.

[0035] Example

[0036] The structure of the laser output lens for the radio frequency carbon dioxide laser provided by the present invention is shown in Table 3.

[0037] Table 3

[0038]

[0039]

[0040] The lens substrate is coated with a coating machine according to the film structure designed in Table 3, and the film data on the laser output lens obtained are shown in Table 4.

[0041] Table 4

[0042] Film 1 2 3 4 5 6 7 8 Material <![CDATA[YF3]]> ZnSe <![CDATA[YF3]]> ZnSe <![CDATA[YF3]]> ZnSe <![CDATA[YF3]]> ZnSe Physical thickness (nm) 1619.05 685.94 1619.05 685.94 1619.05 685.94 1619.05 422.12 Optimize No Yes Yes Yes Yes Yes Yes Yes Yes Group 1 1 1 1 1 1 1 1 Constraint No No No No No No No No No Minimum thickness 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm Maximum thickness 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm 0.0000nm Allow pin insertion? Yes Yes Yes Yes Yes Yes Yes Yes

[0043] The laser output lens with the film structure shown in Table 4 was tested using a transmittance tester to obtain a transmittance curve of the laser output lens provided by the present invention for visible light band lasers. Figure 4 As shown, the transmittance to the red laser with a wavelength of 650nm is not less than 40%, and the specific transmittance range is 48% to 55%.

[0044] By comparing the data in Table 1 and Table 3, it can be concluded that the changes in the lens coating layer 2 of the present invention are: increasing the thickness of YF3 and reducing the thickness of ZnSe.

[0045] In addition, the laser output lens in the comparative example and the laser output lens in the embodiment are tested using a transmittance tester to obtain the transmittance curves of the laser output lenses in the comparative example and the embodiment to the far-infrared band laser. Figure 5 As shown, the thick solid line represents the transmittance curve of the laser output lens in the comparative example to the far-infrared band laser, and the thin solid line represents the transmittance curve of the laser output lens in the embodiment to the far-infrared band laser. It can be concluded that the transmittance of the carbon dioxide laser with a wavelength of 9300nm (at the vertical thin solid line mark) is not less than 20% and the specific transmittance range is 21% to 23%. Therefore, it can be concluded that the laser output lens of the present invention can improve the transmittance of the red laser with a wavelength of 650nm without affecting the transmittance of the carbon dioxide laser.

[0046] The above embodiments are only for illustrating the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention; any technology not involved in the present invention can be realized by existing technologies.

Claims

1. A laser output lens for a radio frequency carbon dioxide laser, the laser output lens comprising a lens substrate (1) made of zinc selenide and a lens coating layer (2), the lens coating layer (2) being composed of a first coating layer (21) made of yttrium fluoride, a second coating layer (22) made of zinc selenide, a third coating layer (23) made of yttrium fluoride, a fourth coating layer (24) made of zinc selenide, a fifth coating layer (25) made of yttrium fluoride, a sixth coating layer (26) made of zinc selenide, a seventh coating layer (27) made of yttrium fluoride and an eighth coating layer (28) made of zinc selenide, which are sequentially arranged on the lens substrate (1), characterized in that: The thickness of the first coating layer (21) is 1618nm-1620nm, the thickness of the second coating layer (22) is 685nm-687nm, the thickness of the third coating layer (23) is 1618nm-1620nm, the thickness of the fourth coating layer (24) is 685nm-687nm, the thickness of the fifth coating layer (25) is 1618nm-1620nm, the thickness of the sixth coating layer (26) is 685nm-687nm, the thickness of the seventh coating layer (27) is 1618nm-1620nm, and the thickness of the eighth coating layer (28) is 421nm-423nm, so that the total thickness of the lens coating layer (2) is 8948nm-8964nm.

2. The laser output lens for radio frequency carbon dioxide laser according to claim 1, characterized in that: The laser output lens formed by the lens coating layer (2) and the lens substrate (1) has a transmittance of not less than 40% for red laser light with a wavelength of 650 nm.

3. The laser output lens for radio frequency carbon dioxide laser according to claim 2, characterized in that: The laser output lens formed by the lens coating layer (2) and the lens substrate (1) has a transmittance of 45% to 55% for red laser light with a wavelength of 650 nm.

4. The laser output lens for radio frequency carbon dioxide laser according to claim 3, characterized in that: The laser output lens formed by the lens coating layer (2) and the lens substrate (1) has a transmittance of 48% to 55% for red laser light with a wavelength of 650 nm.

5. The laser output lens for radio frequency carbon dioxide laser according to claim 1, characterized in that: The laser output lens formed by the lens coating layer (2) and the lens substrate (1) has a transmittance of not less than 20% for carbon dioxide laser with a wavelength of 9300 nm.

6. The laser output lens for radio frequency carbon dioxide laser according to claim 5, characterized in that: The laser output lens formed by the lens coating layer (2) and the lens substrate (1) has a transmittance of 21% to 23% for carbon dioxide laser with a wavelength of 9300 nm.

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