KR20010026352A - Flame hydrolysis apparatus for optical amplifier - Google Patents

Abstract

PURPOSE: A device of flame hydrolysis deposition(FHD) for manufacturing a fiber-optic amplifier is provided to supply Eribum(Er) and Ytterbium(Yb) in the state of liquid through a pipe into the FHD reaction chamber to control the temperature. CONSTITUTION: In a device of flame hydrolysis deposition(FHD) for manufacturing fiber-optic amplifier, a supplier of reaction gas(11) supplies an FHD reaction chamber(12) with liquid reaction gas, inactive gas for transferring the liquid reaction gas and gas used for FHD. The liquid reaction gas undergoes FHD in a FHD reaction chamber(12). A thermostat(13) provides the FHD reaction chamber(12) with solid fuel evaporated by heat. An aerosol generator(14) provides the FHD reaction chamber with dissolved Erbium(Er) and Ytterbium(Yb).

Description

Flame hydrolysis apparatus for optical amplifier

The present invention is a flame hydrolysis device for manufacturing optical components such as optical amplifiers used in optical communication, forming a waveguide on a separate substrate to configure the flow of the optical signal, Erbium (Erbium: Er) and this for the optical signal amplification The present invention relates to a flame hydrolysis apparatus for producing an optical amplifier for adding a glass (Ytterbium: Yb) and the like to produce a glass film.

At this time, the substrate is used, such as silicon, quartz, sapphire, and the like as an additive material for the optical signal amplification, such as erbium and yttrium to control the characteristics of the optical signal, and is used according to the optical amplification function. Glass deposition on the substrate is CVD (Chemical Vapor Deposition) [1], Flame Hydrolysis Deposition (FHD) [2], etc. In the present invention, FHD (Flame Hydrolysis) (AFD) and aerosol flame deposition (AFD) The present invention relates to a flame hydrolysis apparatus for producing a low loss silica optical waveguide by adding erbium and yttrium to a silicon substrate using the Aerosol Flame Deposition method.

[1] BH Verbeek, CH Henry, et al., "Integrated Four Mach-Zender Multi-Demultiplexer Fabricated with Phosphorous Doped SiO ₂ Waveguides on Si," J. Lightwave Technol. Vol. 6, No. 6. 1011 (1988)

[2] M. Kawachi, "Silica Waveguide on Silicon and Their Application to Integrated-Optic Components," Optical and Quantum Electronics, Vol. 22, 391 (1990)

In general, various planar waveguide technologies have been developed to manufacture various integrated optical components such as an optical amplifier, an optical coupler, an optical switch, a wavelength divider, etc. with the development of optical communication technology. Conventional waveguide formation technology for optical component manufacturing defines a core layer by a reaction ion etching method on a silica film (buffer clad, core layer) produced by flame hydrolysis, etc., and forms a silica film (over cladding layer) to form an optical signal. It is made of a structure to induce the flow of. Flame hydrolysis method is a method derived from VAD (Vapor Axial Deposition) method of manufacturing optical fiber, a method of obtaining a densified glass film through the heat treatment process after forming the oxide fine particles by reacting the feedstock in the torch of atmospheric pressure, high temperature. The main parameters of the waveguide characteristics are the transparency of the glass film, the uniform refractive index and the uniform thickness of the waveguide.

The main variables affecting the transparency of the glass film and the characteristics of the waveguide depend greatly on the type and flow rate of the raw materials, the thickness of the product, and the densification temperature and time. In order to use the existing FHD [2] method through the control of such process variables, the flame temperature is high temperature torch reaction of 1200 ~ 1250 ℃ and the melting and densification process temperature of fine particles is 1250 ~ 1380 ℃. Development problems are not completely ruled out. In addition, a solid element, erbium chelate or yttbium chelate, is used as an optical amplification source in a waveguide for fabricating an optical amplifier. Therefore, uniform addition of erbium and yttrium is essential to obtain low loss optical amplification characteristics. However, due to the low vapor pressure of these chelate elements at room temperature, heating through a thermostat is essential for controlling the vapor pressure. Therefore, in order to add the element of erbium and yttrium, it is conventionally required to heat by using a heating wire around the column and the transport tube, so that the temperature device is additionally provided for uniform temperature control around the container and the transport tube. It is essential. In addition, there is a difficulty in uniform temperature control from the storage container to the reaction torch through the transfer line. In addition, the AFD method [3], which is a method of dissolving these elements in a solution for the addition of erbium and yttrium, and then supplying them to the flame hydrolysis apparatus through a transfer tube in an aerosol state.

The uniform addition of erbium and yttbium, which are optical amplification elements for the fabrication of optical amplifiers using conventional FHD methods, has the following problems.

First of all, in the process of direct contact between the substrate and the flame, an unbalance of heat distribution may occur because a part of the substrate is brought into contact with the substrate at room temperature.

Second, since the temperature of the flame is similar to the melting temperature of the oxide fine particles, glass melting may occur inside the quartz tube of the burner, which may cause a fatal contamination of the particle deposition layer by contacting foreign substances in the air.

Third, in order to manufacture an optical amplifier and an optical component using the same, the addition of erbium and yttrium, which is used as an optical amplifier, greatly influences the characteristics of the optical component. This is a light scattering due to a non-uniform distribution of erbium and yttrium, which has a fatal effect on the loss of the optical amplifier. Therefore, the addition of uniform erbium and yttbium is essential. At this time, erbium chelate or yttbium chelate is used as an optical amplification source. However, due to the low vapor pressure of these chelate elements at room temperature, heating through a thermostat is essential for controlling the vapor pressure. Therefore, in order to add the element of erbium and yttrium, it is conventionally required to heat using a heating wire around the storage vessel and the transfer tubes, so that a temperature device is additionally necessary for uniform temperature control around the storage vessel and the transfer tube. In addition, uniform temperature control from the storage vessel to the transfer torch is difficult. Accordingly, there is a difficulty in uniform addition and flow rate control of the elements to be added. In addition, the heating wire should be installed around the valve (valve) installed in the transfer line of the evaporated raw material, it is difficult to uniformly surround the valve around the heating line to generate a local non-uniform temperature distribution. Therefore, erbium chelate or yttbium chelate agglomerates in the part with low temperature distribution, where the heating wire is not wound evenly enough to block the conveying piping, so the entire process of the transfer line must be repaired. The problem arises.

Fourth, since the heating of the column, which is a storage container of erbium chelate or yttrium chelate, is essential, the usage and reaction of commercially available chelate raw materials due to the heating wire wound around the column There is a problem that can not observe the form.

Therefore, in the present invention, by installing a chelate raw material storage container and a transport gas line and a shutoff valve stored in a glass tube in a thermostatically controlled thermostat, the optical amplifier can be solved. It is an object to provide a flame hydrolysis device for.

The present invention enables uniform temperature control of the entire storage vessel and transfer line. In addition, by constructing the AFD method, which is a method of dissolving these elements in a solution for the addition of erbium and yttrium, and then feeding the FHD device through a transfer tube in an aerosol state, the optical amplification sources of erbium and yttrium can be added in various ways Has the advantage.

Flame hydrolysis apparatus according to the present invention for achieving the above object is a reaction gas supply unit for transferring a liquid reaction gas and an inert transport gas for transporting these liquid reaction gas and gas for the flame hydrolysis reaction, and the reaction A flame hydrolysis reaction chamber for causing the liquid reaction gas transferred from a gas supply unit to cause a hydrolysis reaction, a thermostat for heating / evaporating a solid raw material into the flame hydrolysis reaction chamber, and the flame hydrolysis reaction And an aerosol generating unit for supplying erbium and yttrium elements dissolved into the chamber.

The present invention is to fundamentally improve the loss problem caused by the addition of erbium and yttrium element using the conventional FHD method, and to improve the qualitative improvement for the fabrication of optical amplifiers in waveguide type optical passive components to be used in the optical communication network in the future. The purpose.

In addition, the present invention overcomes the above problems with a flame hydrolysis device having a structure that is easy to transfer the chelate (chelate), which is a solid raw material by the FHD method, to facilitate the heating of the temperature of the conveying piping, the erbium as an optical amplification element And precisely control the addition of yttbium and simultaneously utilize the AFD method to produce an ultra low loss silica waveguide for an optical amplifier. Through this technology will be implemented as a base technology for manufacturing optical amplifiers, optical composite modules, and the like.

1 is a block diagram of a flame hydrolysis apparatus according to the present invention.

2 is a block diagram of a flame hydrolysis reaction chamber.

Figure 3 is a schematic diagram of a thermostat for heating / evaporation / transfer of chelate (chelate) raw material.

4 is a configuration diagram of an aerosol generating unit.

<Description of the code | symbol about the principal part of drawing>

11: reaction gas supply part 12: flame hydrolysis reaction chamber

13: thermostat 14: aerosol generating unit

15: check valve

The present invention relates to a flame hydrolysis apparatus for producing an optical amplifier in which a glass film is formed by adding erbium and yttrium using the flame hydrolysis method.

1 is a block diagram of a flame hydrolysis apparatus according to the present invention.

The structure of the flame hydrolysis device is He, Ar, N ₂ , O ₂ , H ₂ and liquid reaction gases such as SiCl ₄ , POCl ₃ , GeCl ₄ , BCl ₃ , which are liquid reaction gases, and inert to transfer these liquid reaction gases. Reaction gas supply unit 11 for transferring carrier gas such as He, Ar, and N ₂ , which are gases, and H ₂ , O ₂ gas for flame hydrolysis reaction by FHD method, flame A flame hydrolysis (FHD) reaction chamber (12) which causes a hydrolysis reaction, a thermostat (13) which is a device for transferring (or heating) the vessel from the vessel containing the solid chelate to the reaction torch in the FHD reaction chamber 12; and The entire system is constituted by the aerosol generating unit 14 which is an apparatus capable of adding elements such as erbium by using the aerosol method.

The thermostat 13, the reaction chamber 12, and the aerosol generating unit 14 use He, Ar, or N2 gas as the transfer gas, and check valves 15a to 15e are provided in the transfer gas line connecting the respective parts. Each is connected, and each check valve (15a to 15e) controls the connection / blocking and back flow of the feed gas.

The reaction gas supply unit 11 generates an oxyhydrogen flame while blowing a liquid material such as SiCl ₄ , GeCl ₄ , BCl ₃ , or POCl ₃ to blow glass inert gas such as He, Ar, or N ₂ to form a glass film. In order to supply H ₂ and O ₂ to the FHD reaction chamber 12 to induce a part. At this time, the raw materials used are SiCl ₄ , GeCl ₄ , BCl ₃ , POCl ₃ (PCl ₃ ) and the like, and most of them are low vapor pressure liquid raw materials, and the characteristics of the gas are shown in [Table 1]. Unlike general gas for semiconductor, it has strong corrosion resistance at low pressure and it is stored in thermostat because it is very sensitive to temperature.

Chemical formula water(%) Vapor pressure Melting point toxicity SiCl ₄ 99.9999 400 Torr (38 ℃) -68.8 ℃ 1.25 ppm POCl ₃ 99.9999 100 Torr (21 ℃) -111.8 ℃ 0.5 ppm BCl ₃ 99.9999 514 Torr (10 ℃) -107.0 ℃ 1.5 ppm GeCl ₄ 99.9999 100 Torr (25 ℃) -49.0 ℃ LC50 44mg / 2H

The liquid and gaseous gases supplied from the reaction gas supply unit 11 form silica fine particles having a diameter of about 0.1 μm by the following reaction in the FHD reaction chamber 12. The reaction formula is represented by Equation 1 below.

SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl + α

GeCl ₄ + 2H ₂ + O ₂ → GeO ₂ + 4HCl + α '

4BCl ₃ + 6H ₂ + 3O ₂ → 2B ₂ O ₃ + 12HCl + α "

The basic composition of the silica fine particles formed through the reaction is SiO ₂ and is composed of GeO ₂ , B ₂ O ₃ , P ₂ O _5, and the like, which are additives for controlling the refractive index and melting point.

2 is a block diagram of a flame hydrolysis reaction chamber in which the reaction proceeds.

The portion of the silica fine particles 27 deposited on the substrate 28 of silicon, quartz, ceramic, or the like by the thermal decomposition reaction with the acid hydrate salt 26 accompanied by the chemical reaction using the reaction torch 29. The reaction torch 29 in the FHD reaction chamber 22 is connected to a thermostat 23 for heating and supplying erbium chelate and yttbium chelate, and a shutoff valve 25a is provided between the chelate transfer pipes inside the thermostat 23. Connected, it serves to block / connect the transport of chelates. In addition, the aerosol generating unit 24 in which erbium and yttrium are dissolved is also connected through the check valve 25c to manufacture an AFD thin film by aerosol. By closing the check valve 25c of the aerosol generating unit 24 and the heating unit for heating the chelate, and directly connecting the FHD reaction chamber 22 through the reaction gas supply unit 21 and the check valve 25a, erbium and yttrium were formed. The glass film which is not added can also be manufactured, and glass film manufacture, such as a light splitter and a photosynthesis splitter, is also possible.

3 is a schematic diagram of a heating thermostat for evaporation / supply after heating of solid erbium chelate and yttrium chelate.

The function of the thermostat 3 is a chelate storage container through the check valve 35 and the shutoff valves 38a and 38b by a carrier gas such as He, Ar, and N ₂ supplied from the reaction gas supply unit 31. The erbium and yttrium chelates charged in the columns 34a and 34b are controlled by a temperature controller 36 equipped with heating and the chelate storage containers 34a and 34b when heated to a temperature above 160 ° C., which is the temperature at which the chelate starts to evaporate. The chelate in) acts to transfer the gas generated by melt decomposition into the FHD reaction chamber 32 by a transfer gas such as He.

At this time, chelate storage containers (34a and 34b), transfer pipes and various shut-off valves (38a to 38d) processed with a transparent material that can withstand the temperature of about 200 ℃, such as glass and quartz, can be seen in the thermostat (3). Configure inside. Therefore, since the temperature distribution is uniform in each part, no heating wire is required, and therefore, clogging of the pipe due to condensation at the part where the heating wire of the conveying pipe such as around the valve is inadvertently wound can be prevented. If the pipe is blocked due to the temperature drop of the pipe due to the temperature unevenness, cleaning and reconstitution of the pipe are inevitable, which leads to enormous disruption to the process. In addition, since the surroundings of the chelate storage containers 34a and 34b made of glass are not heated with a heating wire, the reaction state and degree of reaction of the chelate in the container and the remaining amount after the reaction can be easily checked, thereby facilitating the flow control of the post process. . To this end, the front of the thermostat (3) can be insulated with a transparent body that can withstand high temperatures, such as glass, which can be visually identified, and the door can be installed on the front of the transparent body to prevent heat dissipation from inside. It was configured to be. If you want to observe the interior as needed, configure the switch connected to the swing door connected to the light 33, so that the light is automatically turned on when opening the door, it is easy to check the status of the internal storage container and the transfer pipe from time to time It is configured to be made. In addition, the number of storage containers and the range of temperature control were determined according to the type of chelate element. Erbium chelate and yttbium chelate have similar melting / evaporation temperatures so that the chelate reservoirs 34a and 34b can be configured in the same thermostat. In addition, when the melting / evaporation temperature is lower than these elements, when an element such as PCl3 or PCl5 is used, an independent thermostat is required. In the thermostatic chamber 3, the transfer pipe is connected to the reaction torch 29 of the FHD reaction chamber 32 through the check valve 35b, and the erbium and yttbium elements transferred together with the flame hydrolysis reaction form the silica glass film. Is added. At this time, the flow rate of the chelate is configured to adjust the flow rate of the transport gas, such as He is supplied from the reaction gas supply unit 31 with a flow controller (MFC: Mass Flow Contoller). The shortest possible length of the transfer pipe between the FHD reaction chamber 32 and the thermostat 3 was to prevent the temperature unevenness occurring in the transfer pipe as much as possible. And the pipe before the reaction vessel was configured to 0.25 inches and the transfer pipe after the chelate reaction vessel to 0.5 inches to improve the conductivity (conductance) of the gas in consideration of the vapor pressure generated in the reaction vessel.

4 is a block diagram of an aerosol generating unit.

Flame reaction torch on substrate of silicon, quartz, ceramic, etc. by AFD method, which dissolves these elements in solution to add erbium and yttrium, and then supplies them to FHD reaction chamber 42 through transfer pipe in aerosol state. It is a block diagram of the aerosol generating part 44 for depositing silica microparticles | fine-particles by the thermal decomposition reaction with the acid hydration salt which accompanied the chemical reaction. By using the ultrasonic oscillator 43 installed below the aerosol generating unit 44, a solution in which erbium and yttrium is dissolved is prepared in an aerosol state and supplied to the FHD reaction chamber 42. At this time, the amount of aerosol generated can be increased by increasing the power consumption of the ultrasonic oscillator 43, and by controlling the transfer gas such as He by the flow control meter (MFC) in the reaction gas supply unit 41, the inside of the FHD reaction chamber 42 It was configured to be able to control the amount of aerosol transfer to the reaction torch. And the pipe before the aerosol reaction vessel was configured to 0.25 inches and the transfer pipe after the aerosol reaction vessel was configured to 0.5 inches by considering the vapor pressure generated in the aerosol reaction vessel (conductance) is configured to improve. Reference numerals 45a and 45b, which are not described, denote check valves, 46 denote aerosol regulators, and 47 denote power switches.

Combustion gas and source gas react with various control parameters and gas control mechanism configured as described above to easily add elements such as erbium and yttbium, which are optical amplification elements, on various substrates, especially silicon substrates. To form homogeneous silica particles. The formed fine particles can obtain an optical waveguide glass film through a melting process in a high temperature electric furnace in order to vitrify (densify).

The present invention is to fundamentally improve the loss problem caused by the addition of erbium and yttrium element by using the conventional FHD method, and to improve the quality of the optical amplifier fabrication of waveguide optical passive components to be used in the optical communication network in the future. It is done. The present invention overcomes the above-mentioned problems by manufacturing a flame hydrolysis device having a structure that is easy to transport a chelate, which is a solid raw material by the FHD method, and facilitates the temperature heating of the transfer pipe, thereby adding an optical amplification element. By controlling AF precisely and simultaneously using AFD method, it is possible to effectively add optical amplification elements erbium and yttbium, so that light scattering generated in the optical waveguide can be suppressed as much as possible. A waveguide can be manufactured, and through such a technology, an optical amplifier, an optical composite module, and the like can be manufactured to secure a foundation of the optical communication industry.

Claims (7)

A reaction gas supply unit for transferring a liquid reaction gas, an inert conveying gas for conveying these liquid reaction gases, and a gas for flame hydrolysis reaction; A flame hydrolysis reaction chamber for causing the liquid reaction gas transferred from the reaction gas supply unit to cause a hydrolysis reaction; A thermostat for supplying heated / evaporated solid raw materials into the flame hydrolysis reaction chamber; Flame hydrolysis apparatus for manufacturing an optical amplifier, comprising an aerosol generating unit for supplying erbium and yttrium element dissolved into the flame hydrolysis reaction chamber. The method of claim 1, Flame hydrolysis apparatus for manufacturing an optical amplifier, characterized in that the temperature chamber is maintained uniformly by simultaneously configuring the storage vessel, valve and the transfer pipe inside the thermostat. The method of claim 2, The material of the storage container, the valve and the transfer pipe is a hydrolysis device for manufacturing an optical amplifier, characterized in that composed of any one of metal, ceramic, Teflon. The method of claim 2, Flame hydrolysis apparatus for manufacturing an optical amplifier, characterized in that the installation of a plurality of storage containers in the thermostat. The method of claim 2, The storage container is a flame hydrolysis device for manufacturing an optical amplifier, characterized in that for storing / storing the solid raw material using glass, quartz and transparent containers. The method of claim 1, The solid raw material is a flame hydrolysis apparatus for producing an optical amplifier, characterized in that the solid raw material which can be evaporated by heating at a high temperature of 200 ℃ or less, including rare earth chelates such as erbium, yttrium and PCl ₃ , PCl ₅ and the like. The method of claim 1, Flame hydrolysis apparatus for manufacturing an optical amplifier, characterized in that the interior of the lamp and the thermostat to the inside of the thermostat to observe the inside of the thermostat, and insulated the front of the transparent to prevent heat dissipation.