KR20030083212A - Optical waveguide-type filter device for flattening gain and method for manufacturing the same - Google Patents

Abstract

PURPOSE: A light-wave circuit type gain flattening filter device and a fabricating method thereof are provided to fabricate plural elements on one wafer and enhance the productivity by using a PLC(Planar Light-wave Circuit) fabrication method. CONSTITUTION: A light-wave circuit type gain flattening filter device includes a substrate(20), a bottom clad layer(21), an upper clad layer(26), and a core layer(22'). The bottom clad layer(21) is formed on an upper portion of the substrate(20). The upper clad layer(26) is formed on an upper portion of the bottom clad layer(21). The core layer(22') is formed between the bottom clad layer(21) and the upper clad layer(26). A grating pattern is formed on the core layer(22'). The bottom clad layer(21) and the upper clad layer(26) are formed with high density SiO2 layers. The core layer(22') is formed with SiO2-GeO2 layer.

Description

Optical waveguide-type filter device for flattening gain and method for manufacturing the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide gain flattening filter element and a method for manufacturing the same. More specifically, a wafer is manufactured by manufacturing a device using a planar lightwave circuit (PLC) technology, away from conventional optical fiber manufacturing. The present invention relates to an optical waveguide type gain flattening filter element capable of manufacturing a plurality of devices and a method of manufacturing the same.

In recent years, due to the development of the Internet and multimedia, optical communication has attracted a lot of integrated optical components such as optical combiners, optical wavelength splitters, and optical amplifiers due to the increased capacity and speed of information.

In particular, the optical amplifier gain flattening filter element flattens the gain of the Erbium Doped Fiber Amplifier (EDFA), which is not constant in each wavelength band, and makes the optical signal level constant in the optical amplifier equipment. Play a role.

1 is a schematic perspective view of a conventional gain flattening filter element, which comprises a core layer 1 for guiding light with a large refractive index and a cladding layer 2 for total reflection of light with a small refractive index.

The gain flattening filter element uses a special optical fiber added with Ge to the core layer 1, and is manufactured by forming a chirped grating pattern 3 on the core layer 1 using an exposure apparatus.

The gain flattening filter element emits light having wavelengths different from each other into the core layer 1 by radiating a wavelength satisfying the condition to the clad layer 2 in each of the chirped grating patterns 3. In addition, it serves to output light having a different level to light having a wavelength of a uniform flattened size.

FIG. 2 is a block diagram illustrating a method of manufacturing a gain flattening filter element using a conventional optical fiber, in which light emitted from an argon laser 10 having a wavelength of 244 nm is transmitted to the first and second reflection mirrors 11, 12, the attenuator 13 adjusts the amount of power of light.

Thereafter, the size of the light is expanded in the beam expander 14 and the light is focused in the cylindrical lens 15 to convert the shape of the light from a circular shape to a bar shape.

The light converted into the bar shape is brought into contact with the bottom surface of the phase mask 17 through the phase mask 17 while moving along the scanning mirror 16 moving by the driving stage 19 having a constant step spacing. A chirped grating pattern is formed on the optical fiber 18.

In this way, a chirped grating pattern is formed in the optical fiber 18, thereby producing a gain flattening filter element in the form of an erbium-doped fiber optical amplifier (EDFA) using the optical fiber.

The conventional optical amplifier gain flattening filter element described above is a method in which manufacturing cost of the optical fiber is increased because Ge is doped into the optical fiber, and a chirped lattice pattern is formed on each of the individual optical fibers, which takes a long time to manufacture and mass production. This is a difficult drawback.

In addition, the configuration of the optical system such as a mirror and a lens is essential in the manufacturing process, and if an error occurs in the alignment of the optical system, there is a problem that the yield is lowered.

Accordingly, the present invention has been made to solve the problems described above, and by manufacturing a device using a Planar Lightwave Circuit (PLC) technology to avoid the manufacture of conventional optical fibers, a plurality of devices in one wafer An object of the present invention is to provide an optical waveguide type gain flattening filter element that can be mass produced, and a manufacturing method thereof.

A preferred aspect for achieving the above object of the present invention is a lower clad layer formed on the substrate; An upper clad layer formed on the lower clad layer; An optical waveguide gain flattening filter element comprising a core layer having a chirped lattice pattern formed between the lower clad layer and the upper clad layer is provided.

Another preferred aspect for achieving the above object of the present invention is

Forming a lower clad layer on top of the substrate;

Forming a core layer on the lower clad layer;

Forming a photoresist on the core layer and forming a chirped grating pattern on the photoresist layer by performing a photolithography process on the photoresist;

Etching the core layers by using the photoresist layer as a mask, and separating the core layers to form a chirped lattice pattern in the core layer;

A method of manufacturing an optical waveguide gain flattening filter element is provided that surrounds the core layer and includes an upper cladding layer formed on the lower cladding layer.

Another preferred aspect for achieving the above object of the present invention comprises the steps of: depositing SiO ₂ on top of a silicon wafer to form a lower clad layer;

Performing gomilhwa (Consolidation) a step of depositing a SiO ₂ -GeO ₂ layer on top of said lower cladding layer, and heating the deposited layer at a high temperature to the SiO ₂ -GeO ₂ and a;

Aluminum is deposited on the SiO ₂ -GeO ₂ layer on which the densification process is performed by using a sputtering apparatus, a photoresist layer is formed on the deposited aluminum layer, and then softbaked using a dry oven. Performing the step;

After performing the soft baking, exposing the photoresist layer using ultraviolet light using a chrome mask having a chirped lattice pattern, and performing a photolithography process to form a photoresist layer having the chirped lattice pattern; ;

Forming a core layer having a chirped lattice pattern by sequentially removing the aluminum layer and the SiO ₂ -GeO ₂ layer by dry or wet etching using the photoresist layer having the chirped lattice pattern as a mask;

A method of manufacturing an optical waveguide type gain flattening filter element is provided that surrounds a core layer having the chirped lattice pattern and comprises an upper cladding layer formed on the lower cladding layer.

1 is a schematic perspective view of a conventional gain flattening filter element for optical communication.

2 is a block diagram showing a method of manufacturing a gain flattening filter element using a conventional optical fiber.

3A to 3L are manufacturing process diagrams of the optical waveguide type gain flattening filter element according to the present invention.

4 is a schematic diagram of an optical waveguide type gain flattening filter element according to the present invention.

<Description of Symbols for Main Parts of Drawings>

1, 22 ': core layer 2: clad layer

3: chirped lattice pattern 10: laser

11,12: reflection mirror 13: attenuator

14 beam expander 15 cylindrical lens

16: scanning mirror 17: phase mask

18: optical fiber 19: drive stage

20 wafer 21 lower clad layer

22: SiO ₂ -GeO ₂ layer 23: aluminum layer

24 photoresist layer 25 chrome mask

26: upper cladding layer

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

3A to 3L are manufacturing process diagrams of an optical waveguide gain flattening filter element according to the present invention. First, after cleansing the silicon wafer 20 in FIG. 3A, the flame hydrolysis deposition (FHD) equipment is used. (B) forming a lower clad layer 21 by depositing SiO ₂ using Chemical Vapor Deposition (CVD) equipment (FIG. 3b).

Thereafter, to form a core layer to be guided with light, a SiO ₂ -GeO ₂ layer 22 is deposited (FIG. 3C), and the deposited SiO ₂ -GeO ₂ layer 22 is heated in a high temperature furnace. A consolidation process is performed to form fine porous silica into a high density thick film (FIG. 3D).

Next, aluminum is deposited on the SiO ₂ -GeO ₂ layer 22 where the densification process is performed by using a sputtering equipment (FIG. 3E), and the photoresist layer 24 is formed on the deposited aluminum layer 23. ) Is then softbaked using a dry oven (Fig. 3g).

After performing the soft baking, using a chrome mask 25 having a chirped lattice pattern is exposed using ultraviolet light to react only the photoresist of the portion lighted by the chrome mask (Fig. 3g) and immersed in the developer In the photolithography process, the reacted photoresist is removed, leaving only the photoresist layer 24 'having the chirped lattice pattern (FIG. 3H).

Subsequently, using the photoresist layer 24 'having the chirped lattice pattern as a mask, the aluminum layer 23 and the SiO ₂ -GeO ₂ layer 22 are sequentially removed by dry or wet etching (FIG. 3I). )

The remaining photoresist layer 24 'and the aluminum layer 23' are removed to form a core layer 22 'having a chirped lattice pattern (FIG. 3J).

Finally, by enclosing the core layer 22 ′ having the chirped lattice pattern, and forming an upper cladding layer 26 on the lower cladding layer 21, an optical gain for an erbium-doped fiber optical amplifier (EDFA). A flattening filter element is manufactured (Fig. 3L).

The core layer having the chirped lattice pattern is etched into the lattice pattern in which the core layer is chirped, whereby the lattice patterns chirped by the separated core layers are formed.

4 is a schematic diagram of an optical waveguide gain flattening filter element according to the present invention, wherein a core layer having a chirped lattice pattern between the lower cladding layer 21 and the upper cladding layer 26 formed on the substrate 20 ( 22 ') is formed.

The light input to the waveguide optical gain flattening filter of the present invention passes through the core layer 22 ′ having the chirped grating pattern, and is radiated by the power of the beam to be flattened to output the flattened light.

As described in detail above, the present invention eliminates the manufacture of conventional optical fibers and manufactures devices using Planar Lightwave Circuit (PLC) technology, thereby allowing mass production of a large number of devices on one wafer. It can reduce the manufacturing cost, there is an effect that can be applied to various optical amplifiers.

Although the invention has been described in detail only with respect to specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (5)

A lower clad layer formed on the substrate; An upper clad layer formed on the lower clad layer; And a core layer having a chirped lattice pattern formed between the lower cladding layer and the upper cladding layer. The method of claim 1, The lower and upper cladding layer is densified SiO ₂ , The core layer is an optical waveguide type gain flattening filter element, characterized in that the SiO ₂ -GeO ₂ layer. The method according to claim 1 or 2, The chirped grating pattern is an optical waveguide gain flattening filter element, characterized in that the core layer is etched to form a separate core layer. Forming a lower clad layer on top of the substrate; Forming a core layer on the lower clad layer; Forming a photoresist on the core layer and forming a chirped grating pattern on the photoresist layer by performing a photolithography process on the photoresist; Etching the core layers by using the photoresist layer as a mask, and separating the core layers to form a chirped lattice pattern in the core layer; A method of manufacturing an optical waveguide gain flattening filter element surrounding the core layer, the method comprising forming an upper cladding layer on the lower cladding layer. Depositing SiO ₂ on top of the silicon wafer to form a lower clad layer; Performing gomilhwa (Consolidation) a step of depositing a SiO ₂ -GeO ₂ layer on top of said lower cladding layer, and heating the deposited layer at a high temperature to the SiO ₂ -GeO ₂ and a; Aluminum is deposited on the SiO ₂ -GeO ₂ layer on which the densification process is performed by using a sputtering apparatus, a photoresist layer is formed on the deposited aluminum layer, and then softbaked using a dry oven. Performing the step; After performing the soft baking, exposing the photoresist layer using ultraviolet light using a chrome mask having a chirped lattice pattern, and performing a photolithography process to form a photoresist layer having the chirped lattice pattern; ; Forming a core layer having a chirped lattice pattern by sequentially removing the aluminum layer and the SiO ₂ -GeO ₂ layer by dry or wet etching using the photoresist layer having the chirped lattice pattern as a mask; A method of manufacturing an optical waveguide type gain flattening filter element surrounding the core layer having the chirped lattice pattern, the method comprising forming an upper clad layer on the lower clad layer.