CN112198593A

CN112198593A - Manufacturing method of CWDM optical filter

Info

Publication number: CN112198593A
Application number: CN202011085167.4A
Authority: CN
Inventors: 陈喜文; 尹智辉; 赵刚科
Original assignee: Dongguan Viko Optics Technology Co ltd
Current assignee: Dongguan Viko Optics Technology Co ltd
Priority date: 2020-10-12
Filing date: 2020-10-12
Publication date: 2021-01-08

Abstract

The invention discloses a manufacturing method of a CWDM optical filter, which comprises the following steps: s1, providing a substrate, a low-refractive-index target material and a high-refractive-index target material, wherein the high-refractive-index target material is a silicon-aluminum target; s2, plating a low-refractive-index film layer on the surface of the substrate; s3, sputtering the silicon-aluminum target to the surface of the substrate in a medium-frequency sputtering coating mode, and filling hydrogen into the silicon-aluminum target in the sputtering process, so that a high-refractive-index film layer is coated on the surface of the substrate, wherein the high-refractive-index film layer is an SiH film layer; s4, repeating the steps S2 and S3 in turn until the target layer is plated. Compared with the Ta2O5 film layer in the prior art, the SiH film layer with high refractive index is plated on the surface of the substrate in a medium-frequency sputtering film plating mode, so that the CWDM optical filter has the advantages of higher refractive index, easier film layer design, shorter film plating time, low raw material cost, easiness in mass production, better optical performance and higher popularization and application value.

Description

Manufacturing method of CWDM optical filter

Technical Field

The embodiment of the invention relates to the technical field of optical communication, in particular to a manufacturing method of a CWDM optical filter.

Background

With the coming of the information age, the demand of people on optical communication bandwidth is increasing dramatically, and there are two methods for increasing the optical path bandwidth: firstly, the single channel transmission rate of the optical fiber is improved; secondly, the number of wavelengths transmitted in a single optical fiber is increased, namely, the Wavelength Division Multiplexing (WDM) technology is adopted.

At present, BMAN (Broadband Metropolitan Area Network) is becoming a hotspot of information-based construction, and the huge bandwidth and the transparency of transmission data of DWDM (Dense Wavelength Division Multiplexing) are undoubtedly the first choice technology in the field of current optical fiber application. However, MAN (metropolian Area Network, Metropolitan Area Network) and the like have the characteristics of short transmission distance, flexible topology, multiple access types and the like, and the cost is inevitably too high if DWDM used for long-distance transmission is carried; while the flexible diversity of early DWDM towards MAN and the like is difficult to adapt. In response to the broadband requirement of the low-cost metropolitan area, the CWDM (Coarse wavelength division multiplexing) technology has come into force and is a practical device.

CWDM is a low cost WDM transmission technique oriented towards the metro network access layer. In principle, the CWDM technique is to multiplex optical signals with different wavelengths to a single optical fiber by using an optical multiplexer for transmission, then at a receiving end of a link, decompose a mixed signal in the optical fiber into signals with different wavelengths by using an optical-static multiplexer, and finally connect the signals to corresponding receiving devices.

The CWDM optical filter is an important device for distinguishing different wavelengths, high-refractive-index and low-refractive-index optical films are alternately plated on an optical substrate by using a precise optical coating technology, so that high transmittance in 1217nm, 1291nm, 1311nm, 1331nm, 1351nm and 1371nm wave bands can be realized, and the rest wave bands are cut off.

In the prior art, the CWDM optical filter uses high-refractive index materials and low-refractive index materials to achieve the effect by alternately stacking different film layers through a sputtering film plating machine. Generally used high refractive index materials include Ti3O5, Nb2OB, Ta2O5, etc., and low refractive index materials include SiO2, etc. However, the high refractive index material used in the existing film-based layer of the CWDM filter is Ta2O5, which has the following three disadvantages:

firstly, the Ta2O5 has a low refractive index, which brings great difficulty to the theoretical design of a film system;

secondly, the film layer is thicker, in order to realize the optical function, the film layer is designed to reach 150 layers, the film coating time consumption is long, and the equipment operation cost is high;

third, the material is expensive, and Ta2O5 uses a relatively expensive Ta target.

Therefore, if a CWDM filter with a higher refractive index, a smaller number of film layers, and a lower cost can be developed, all the above problems and disadvantages can be well solved, the scientific research field and the service information life can be developed, and the market prospect thereof can be also considerable.

Disclosure of Invention

The invention provides a manufacturing method of a CWDM optical filter, which aims to overcome the defects in the prior art.

In order to achieve the above purpose, the present invention provides the following technical solutions:

a method for manufacturing a CWDM filter, the method comprising:

s1, providing a substrate, a low-refractive-index target material and a high-refractive-index target material, wherein the high-refractive-index target material is a silicon-aluminum target;

s2, plating a low-refractive-index film layer on the surface of the substrate;

s3, sputtering the silicon-aluminum target to the surface of the substrate in a medium-frequency sputtering coating mode, and filling hydrogen into the silicon-aluminum target in the sputtering process, so that a high-refractive-index film layer is coated on the surface of the substrate, wherein the high-refractive-index film layer is an SiH film layer;

s4, repeating the steps S2 and S3 in turn until the target layer is plated.

Further, in the method for manufacturing the CWDM filter, the step S2 includes:

s21, sputtering the low-refractive-index target to the surface of the substrate in a low-frequency sputtering coating mode, filling argon into the low-refractive-index target in the sputtering process, and adopting an ion source for assistance;

and S22, filling oxygen into the low-refractive-index target material to plate a low-refractive-index film layer on the surface of the substrate.

Further, in the manufacturing method of the CWDM optical filter, the low refractive index target material is a pure silicon target.

Further, in the manufacturing method of the CWDM filter, the low refractive index film layer is a SiO2 film layer.

Further, in the method for manufacturing the CWDM filter, the substrate is D263T or K9 glass having high transmittance.

Further, in the manufacturing method of the CWDM optical filter, the number of the target layers is 60-100.

Further, in the method for manufacturing the CWDM filter, the number of target layers is 83.

In the method for manufacturing the CWDM filter, among the odd number of 83 layers among the target number of layers, the 1 st, 5 th, 9 th, 11 th, 19 th, 67 th, 71 th, and 79 th layers have a thickness of 222.84nm, the 3 rd and 8 th layers have a thickness of 445.68nm, the 13 th, 15 th, 17 th, 21 th, 23 th, 25 th, 27 th, 29 th, 31 th, 33 th, 35 th, 37 th, 39 th, 41 th, 43 th, 45 th, 47 th, 49 th, 51 th, 53 th, 55 th, 57 th, 59 th, 61 th, 63 th, 65 th, 69 th, 73 th, and 75 th layers have a thickness of 668.52nm, the 7 th and 77 th layers have a thickness of 1337.04nm, and the 83 th layer has a thickness of 150.42 nm.

Further, in the method for manufacturing the CWDM filter, among the even layers among the 83 target layers, the 2 nd, 4 th, 6 th, 8 th, 10 th, 16 th, 22 th, 28 th, 34 th, 40 th, 46 th, 52 th, 58 th, 64 th, 70 th, 76 th, 78 th, and 80 th layers have a thickness of 97.53nm, the 12 th, 18 th, 24 th, 30 th, 36 th, 42 th, 48 th, 54 th, 60 th, 66 th, and 72 th layers have a thickness of 195.07nm, the 14 th, 20 th, 26 th, 32 th, 38 th, 44 th, 50 th, 56 th, 62 th, 68 th, and 74 th layers have a thickness of 292.6nm, and the 82 th layer has a thickness of 86.61 nm.

Further, in the manufacturing method of the CWDM optical filter, in the step S3, the frequency of the intermediate frequency sputtering coating is 20 to 60 KHZ.

According to the manufacturing method of the CWDM optical filter, the SiH film layer with the high refractive index is plated on the surface of the substrate in the medium-frequency sputtering film plating mode, compared with the Ta2O5 film layer in the prior art, the SiH film layer with the high refractive index is higher in refractive index, the film layer is easier to design, the film plating time is shorter, the raw material cost is low, the mass production is easy, the optical performance of the CWDM optical filter can be better, and the CWDM optical filter has higher popularization and application values.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a schematic flow chart of a method for manufacturing a CWDM filter according to an embodiment of the present invention;

fig. 2 is a schematic flow chart of a method for manufacturing a CWDM filter according to an embodiment of the present invention;

fig. 3 is a schematic view of a film coating process of the method for manufacturing a CWDM filter according to the embodiment of the present invention;

fig. 4 is a schematic diagram of a sputtering coating in the manufacturing method of the CWDM filter according to the embodiment of the present invention.

Detailed Description

In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present.

Furthermore, the terms "long", "short", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention, but do not indicate or imply that the referred devices or elements must have the specific orientations, be configured to operate in the specific orientations, and thus are not to be construed as limitations of the present invention.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

Example one

In view of the defects of the conventional film layer of the CWDM filter, the applicant of the present invention is based on the practical experience and professional knowledge of many years of design and manufacture of such products, and actively performs research and innovation in cooperation with the application of theory, so as to hopefully create a CWDM filter capable of avoiding the defects in the prior art, so that the CWDM filter has higher practicability. After continuous research and design and repeated trial production and improvement, the invention with practical value is finally created.

Referring to fig. 1 to 2, an embodiment of the invention provides a method for manufacturing a CWDM filter, including the following steps:

s1, providing a substrate, a low-refractive-index target material and a high-refractive-index target material, wherein the high-refractive-index target material is a silicon-aluminum target.

The low-refractive-index target material is a pure silicon target; the substrate is glass with high transmittance in 1271 wave band, such as D263T or K9.

And S2, plating a low-refractive-index film layer on the surface of the substrate.

The low refractive index film layer is an SiO2 film layer.

Preferably, the step S2 specifically includes the following steps:

Specifically, when the target material chamber with low refractive index is rotated, a medium-frequency sputtering coating mode is adopted from top to bottom, wherein a sputtering source is arranged on the upper part, and a substrate is arranged on the lower part; during coating, the substrate rotates clockwise perpendicular to the sputtering direction at the speed of 180 circles/min. And coating the film by a low-frequency sputtering mode, introducing argon, adopting an ion source for assistance, ionizing the argon to generate electrons so as to start film formation, and introducing oxygen to react with the sputtered silicon film layer to form a SiO2 film layer on the surface of the substrate.

S3, sputtering the silicon-aluminum target to the surface of the substrate in a medium-frequency sputtering coating mode, and filling hydrogen into the silicon-aluminum target in the sputtering process, so that a high-refractive-index film layer is coated on the surface of the substrate, wherein the high-refractive-index film layer is an SiH film layer.

In this step, the frequency used for the intermediate frequency sputtering coating is 20 to 60KHZ, for example, 40 KHZ.

Specifically, when the target material chamber is turned to a high-refractive index target material chamber, a medium-frequency sputtering coating mode is adopted from top to bottom, wherein a sputtering source is arranged on the upper portion, and a substrate is arranged on the lower portion; during coating, the substrate rotates clockwise perpendicular to the sputtering direction at the speed of 180 circles/min. Coating a film by a medium-frequency (40KHZ) sputtering mode, and directly filling hydrogen into a silicon-aluminum target to react in the sputtering process of the silicon-aluminum target to obtain a high-refractive-index SiH film layer with aluminum (the silicon-aluminum content ratio is 40: 1); because no ion source hydrogen filling reaction is adopted, the SiH film layer does not need to be opened to assist film formation, the stress is reduced, the deformation is reduced, the visible light wave band of the obtained SiH material can reach more than 5, the refractive index of the infrared 800-1000nm wave band is more than 3.5, the refractive index of the infrared 1100-1500nm wave band is about 3, the transmission bandwidth of the refractive index is wide, and the performance is suitable for mass production.

S4, repeating the steps S2 and S3 in turn until the target layer is plated.

It should be noted that, in the CWDM filter designed in the prior art, the high refractive index material is Ta2O5 (tantalum pentoxide), the low refractive index material is SiO2 (silicon dioxide), and the number of designed film layers is as many as 150, whereas in this embodiment, a film system layer with few film layers, low peak insertion loss, and low flatness can be designed by using SiH (silicon hydride) instead of Ta2O5, which is matched with SiO 2; specifically, the number of layers of a film layer designed by adopting SiH to replace Ta2O5 is reduced by nearly half and is only 60-100, 83 layers are taken as an example in the embodiment, when light vertically enters through an OSA optical measuring instrument at an angle of 0 degree, the central wavelength is 1271nm, the passband range is 1264.6-1278.4 nm, the isolation band is 1250-1258 nm and 1283-1638 nm, the peak insertion loss is 0.05db, the reflection isolation in the passband is 24db, and the transmission isolation in the passband is 48 db.

Preferably, each layer is plated to the designed thickness by physical vapor deposition according to the designed film layer distribution, which is as follows:

in the odd-numbered layers, the thickness of the 1 st, 5 th, 9 th, 11 th, 19 th, 67 th, 71 th and 79 th layers is 222.84nm, the thickness of the 3 rd and 8 th layers is 445.68nm, the thickness of the 13 th, 15 th, 17 th, 21 th, 23 th, 25 th, 27 th, 29 th, 31 th, 33 th, 35 th, 37 th, 39 th, 41 th, 43 th, 45 th, 47 th, 49 th, 51 th, 53 th, 55 th, 57 th, 59 th, 61 th, 63 th, 65 th, 69 th, 73 th and 75 th layers is 668.52nm, the thickness of the 7 th and 77 th layers is 1337.04nm, and the thickness of the 83 th layer is 150.42 nm.

Of the even numbered layers, the 2 nd, 4 th, 6 th, 8 th, 10 th, 16 th, 22 th, 28 th, 34 th, 40 th, 46 th, 52 th, 58 th, 64 th, 70 th, 76 th, 78 th, 80 th layers are 97.53nm thick, the 12 th, 18 th, 24 th, 30 th, 36 th, 42 th, 48 th, 54 th, 60 th, 66 th, 72 th layers are 195.07nm thick, the 14 th, 20 th, 26 th, 32 th, 38 th, 44 th, 50 th, 56 th, 62 th, 68 th, 74 th layers are 292.6nm thick, and the 82 th layer is 86.61nm thick.

Referring to fig. 3, fig. 3 is a schematic view of a coating process of the method of the present invention. In the figure: a is cathode (cathode) intermediate frequency sputtering, B is target material (silicon aluminum target), C is reactive gas ion, D is target material particle, E is free electron, F is deposition coating, G is base material, H is base material fixer and anode (anode).

Referring to fig. 4, fig. 4 is a schematic diagram of sputter coating in the method of the present invention. Sputtering coating is a technique of bombarding the surface of a target with energetic particles in vacuum to deposit the bombarded particles on a substrate. Typically, a low pressure noble gas glow discharge is used to generate the incident ions. The cathode target is made of coating material, the substrate is used as anode, argon (Ar2) or other inert gas with 0.1-10Pa is introduced into the vacuum chamber, and glow discharge is generated under the action of cathode (target) 1-3KV direct current negative high voltage or radio frequency voltage of 13.56 MHz. The ionized argon ions bombard the target surface causing target atoms to sputter and deposit onto the substrate, forming a coating (e.g., Si), which is then oxidized by oxygen (e.g., SiO2) to form a thin film.

Although terms such as substrate, film-based layer, low refractive index film layer, high refractive index film layer, etc. are used more often in this application, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention.

The foregoing description of the embodiments has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same elements or features may also vary in many respects. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous details are set forth, such as examples of specific parts, devices, and methods, in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In certain example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises" and "comprising" are intended to be inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed and illustrated, unless explicitly indicated as an order of performance. It should also be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being "on" … … "," engaged with "… …", "connected to" or "coupled to" another element or layer, it can be directly on, engaged with, connected to or coupled to the other element or layer, or intervening elements or layers may also be present. In contrast, when an element or layer is referred to as being "directly on … …," "directly engaged with … …," "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship of elements should be interpreted in a similar manner (e.g., "between … …" and "directly between … …", "adjacent" and "directly adjacent", etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region or section from another element, component, region or section. Unless clearly indicated by the context, use of terms such as the terms "first," "second," and other numerical values herein does not imply a sequence or order. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as "inner," "outer," "below," "… …," "lower," "above," "upper," and the like, may be used herein for ease of description to describe a relationship between one element or feature and one or more other elements or features as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below … …" can encompass both an orientation of facing upward and downward. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted.

Claims

1. A method for manufacturing a CWDM optical filter is characterized in that the method comprises the following steps:

s2, plating a low-refractive-index film layer on the surface of the substrate;

s4, repeating the steps S2 and S3 in turn until the target layer is plated.

2. The method of claim 1, wherein the step S2 includes:

3. The method of claim 1, wherein the low refractive index target material is a pure silicon target.

4. The method of claim 1, wherein the low refractive index film layer is a SiO2 film layer.

5. The method of claim 1, wherein the substrate is D263T or K9 glass with high transmittance.

6. The method of claim 1, wherein the number of target layers is 60-100.

7. The method of claim 6, wherein the number of target layers is 83.

8. The method of claim 7, wherein among the odd layers among the 83 target layers, the 1 st, 5 th, 9 th, 11 th, 19 th, 67 th, 71 th and 79 th layers have a thickness of 222.84nm, the 3 rd and 8 th layers have a thickness of 445.68nm, the 13 th, 15 th, 17 th, 21 th, 23 th, 25 th, 27 th, 29 th, 31 th, 33 th, 35 th, 37 th, 39 th, 41 th, 43 th, 45 th, 47 th, 49 th, 51 th, 53 th, 55 th, 57 th, 59 th, 61 th, 63 th, 65 th, 69 th, 73 th and 75 th layers have a thickness of 668.52nm, the 7 th and 77 th layers have a thickness of 1337.04nm, and the 83 th layer has a thickness of 150.42 nm.

9. The method of claim 7, wherein the even number of the 83 th layers include 97.53nm for the 2 nd, 4 th, 6 th, 8 th, 10 th, 16 th, 22 th, 28 th, 34 th, 40 th, 46 th, 52 th, 58 th, 64 th, 70 th, 76 th, 78 th and 80 th layers, 195.07nm for the 12 th, 18 th, 24 th, 30 th, 36 th, 42 th, 48 th, 54 th, 60 th, 66 th and 72 th layers, 292.6nm for the 14 th, 20 th, 26 th, 32 th, 38 th, 44 th, 50 th, 56 th, 62 th, 68 th and 74 th layers, and 86.61 th layer.

10. The method of claim 1, wherein in step S3, the frequency of the intermediate frequency sputtering coating is 20-60 KHZ.