CN115586610A - Low-power-consumption high-efficiency heating or refrigerating method - Google Patents

Abstract

The invention provides a low-power-consumption high-efficiency heating or refrigerating method, which is used for solving the technical problem that a series of performance degradation costs are caused by different temperature gradients in use due to the existing heating or refrigerating main body in a square solid shape. The invention comprises a heating or refrigerating component, wherein redundant parts of the heating or refrigerating component are removed on the basis of square or sheet shape to form a C-shaped or other special-shaped structure. The invention adopts the heating or refrigerating part with the C-shaped or other special-shaped structure to reduce the temperature-related characteristic of the optical waveguide chip and further solve the problems of thermal stress change, temperature gradient change and heating stabilization time, thereby improving various performances and product yield of the product; the technical problems of flatter temperature compensation curve, smaller thermal stress, better temperature characteristics of various optical indexes, lower power consumption, quicker response time, lower cost and the like are effectively solved.

Description

Low-power-consumption high-efficiency heating or refrigerating method

Technical Field

The invention relates to the technical field of optical communication, in particular to a low-power-consumption high-efficiency heating or refrigerating method, especially to a heating method of an optical waveguide chip, which is an effective method for reducing heating power consumption, improving heating response time and improving heating effect.

Background

In different application fields, different material systems are adopted to manufacture the optical waveguide integrated device. Materials systems commonly used in the field of optical communications are: silicon, silicon dioxide, silicon nitride, silicon oxynitride, polymer, lithium niobate and III-V cluster, and the materials have larger thermo-optic effect. The temperature of the optical waveguide chip made of these materials changes with the change of the environmental temperature or in the power-on operating state, which results in the serious deterioration of the device performance. In actual product commercial application, a heater or a Peltier (Peltier) cooler is basically required to be added for temperature control, and a temperature control circuit is adopted to enable the heater or the Peltier cooler to be in a constant temperature environment, so that the optical performance of the device is not deteriorated. For a long time, research institutes have been dedicated to continuously improving the performance parameters of the waveguide chip itself, reducing the size and the cost, and have achieved remarkable results, but neglecting the improvement of the packaging technology, the research on the temperature control main body such as a heater or a Peltier (Peltier) refrigerator is lacked.

In practical product applications, a heating or cooling device comprises two parts: the heating or refrigerating body, the PLC optical waveguide chip that is heated or refrigerated. At the beginning of the business, both parts were square solids. In order to reduce cost and improve product competitiveness, technologists propose to design a square optical waveguide chip into a 'C' shape, so that more chips can be placed on one wafer, thereby effectively reducing cost. But for a long time the heating or cooling body itself, up to now, is still a square entity. With the continuous development of the technology, more and higher requirements are put on optical communication devices, for example, the rigorous requirements in the aspects of cost reduction, power consumption reduction, response time increase, performance degradation cost caused by temperature change and the like are required to be continuously solved by wide technical workers.

The current practical product application adopts a heating or refrigerating main body in a square solid shape, and a temperature sensor and a temperature control circuit are used for realizing that an optical communication device always works at a stable working temperature point, but the temperature detecting point of the temperature sensor is only one point on a detecting optical chip, and the temperature sensitive area of the optical chip is an area. When the ambient temperature changes, although the temperature of the temperature detection point monitoring control of the temperature sensor is constant, the temperature gradient of other areas except the point is different, and the difference of the temperature gradient brings a series of performance degradation costs. The performance deterioration cost is acceptable in the early stage of product use; with the deep development of the technology, the performance of the product is continuously improved, and the performance degradation cost caused by the temperature gradient is necessarily reduced.

Disclosure of Invention

Aiming at the technical problems that the heating or refrigerating main body in the shape of the existing square entity has different temperature gradients and brings a series of performance degradation costs, the invention provides a low-power-consumption high-efficiency heating or refrigerating method, the shape of a heating or refrigerating part is designed according to the shape of a heated part, and the shape, the volume and the quality of the heating or refrigerating part are reduced to the maximum extent, so that the performance degradation costs brought by the temperature gradients can be greatly reduced, for example: the temperature compensation curve is flatter, the thermal stress is smaller, the temperature characteristics of various optical indexes are better, the power consumption is lower, the response time is faster, the cost is lower and the like.

In order to achieve the purpose, the technical scheme of the invention is realized as follows: a low-power-consumption high-efficiency heating or refrigerating method comprises a heating or refrigerating part, wherein redundant parts of the heating or refrigerating part are removed on the basis of square or sheet to form a C-shaped or other special-shaped structure.

Preferably, the material system of the heating or cooling part is at least one of silicon, silicon dioxide, silicon nitride, silicon oxynitride, polymer, lithium niobate, and III-V cluster.

Preferably, the optical fiber is applied to one or more of optical splitters, arrayed waveguide gratings, mach-Zehnder interferometers, variable optical attenuators and arrays, optical switches and arrays, multicast switching optical switches, optically tunable wavelength division multiplexing/demultiplexing devices, reconfigurable optical add-drop multiplexers, differential quadrature phase-contrast keying demodulators and mixers.

Preferably, the arrayed waveguide grating comprises a C-shaped heating or refrigerating component, a C-shaped AWG waveguide chip is arranged on the C-shaped heating or refrigerating component, and the outer edge of the C-shaped heating or refrigerating component is arranged on the outer side of the AWG waveguide chip.

Preferably, the "C" shaped heating or cooling component is connected to the temperature control circuit to make the AWG waveguide chip operate at a certain fixed temperature.

The optical characteristics of the optical waveguide chip are temperature sensitive and stress sensitive, and the performance index of the product is deteriorated due to the change of temperature and stress, so that the commercial product must solve the two key technologies. The method for solving the temperature sensitivity problem is to use a heating or refrigerating main body and a thermistor to control the working temperature of the optical waveguide chip, the three components are fixed together by glue, but the thermal expansion coefficients of the heating or refrigerating main body, the bonding glue and the optical waveguide chip are different, so that the problem of thermal stress is caused. The area of the temperature detecting point of the thermistor is less than 0.5 square millimeter, but the size of the optical waveguide chip is large, the length and the width of the optical waveguide chip are dozens of millimeters, and the area of the heating or refrigerating main body in the square solid shape used in the prior art is more than 1000 square millimeters. When the environmental temperature changes, although the temperature of the thermistor temperature detection point is kept constant, the temperature and the temperature field distribution of other areas except the thermistor temperature detection point are different along with the change of the environmental temperature. The heating or refrigerating body, the thermistor, the optical waveguide chip and the bonding glue constitute a whole, which is called as a temperature control module, and the larger the size of the temperature control module is, the worse the uniformity of the temperature fields of the heating sheet and the optical waveguide chip is, and the larger the gradient of the temperature fields is. The uniformity of the temperature field is poor, so that the wavelength of the product is greatly changed at different working temperatures, and the temperature compensation curve is uneven; the larger the temperature field gradient is, the larger the thermal stress applied to the optical waveguide chip is due to the different thermal expansion coefficients of the related components, which further deteriorates the wavelength accuracy and the flatness of the temperature compensation curve under different temperature working conditions, and deteriorates the product performance. Meanwhile, the larger the size of the temperature control module is, the larger the quality to be heated or cooled is, and therefore, the larger the required heating or cooling power is, the slower the heating rate is and the higher the cost is.

In order to reduce the performance degradation problem caused by the temperature sensitive characteristic and the stress sensitive characteristic of a product and improve the product competitiveness, through a large number of theoretical analysis and engineering verification, under the condition that the size of an optical waveguide chip cannot be reduced, the shape, the volume and the quality of a heating or refrigerating part are reduced to the maximum extent, and the technical problems of flatter temperature compensation curve, smaller thermal stress, better temperature characteristics of various optical indexes, lower power consumption, quicker response time, lower cost and the like can be effectively solved.

The invention has the beneficial effects that: the shape of the heating or cooling component is designed according to the shape of the heated or cooling component, so that the shape, the volume and the mass of the heating or cooling component are effectively reduced; the shape of the heating or refrigerating part is not square or sheet in the prior art, but is a 'C' shape or other special-shaped structures formed by removing redundant parts on the basis of the square or sheet. The heating or refrigerating part with a C-shaped or other special-shaped structure is adopted to reduce the temperature-related characteristics of the optical waveguide chip, and further solve the problems of thermal stress change, temperature gradient change and heating stabilization time, thereby improving various performances and product yield of the product; the technical problems of flatter temperature compensation curve, smaller thermal stress, better temperature characteristics of various optical indexes, lower power consumption, quicker response time, lower cost and the like are effectively solved. The heating or refrigerating part of the 'C' shape is smaller in size, the distribution of the temperature field is more uniform, and therefore the wavelength temperature drift characteristic of the AWG is flatter in the working temperature range; the smaller size of the "C" shaped heating or cooling element and the smaller temperature gradient make the optical properties of the AWG better over the operating temperature range.

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, 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 the drawings without creative efforts.

Fig. 1 is a schematic diagram of the structure of the AWG waveguide chip of the present invention.

Fig. 2 is a schematic structural diagram of a conventional square solid heating or cooling body.

Fig. 3 is a schematic diagram of a prior art architecture using square solid heating or cooling components to heat or cool the AWG chip.

Fig. 4 is a schematic structural view of a "C" shaped heating or cooling element according to the present invention.

Fig. 5 is a schematic diagram of the structure proposed by the present invention using a "C" shaped heating or cooling component to heat or cool the AWG chip.

In the figure, 1-AWG waveguide chip; 2-square solid heating or refrigerating main body; 3- "C" shape heating or refrigerating part.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

Fig. 1 shows a prior art "C" shaped AWG chip that can place more AWG chips on a single wafer, thus greatly reducing the cost of the AWG chip. Fig. 2 shows a square heating or cooling component used in the prior art, wherein the "C" shaped AWG waveguide chip 1 and the square solid heating or cooling body 2 are bonded together by glue, so as to form the prior art solution shown in fig. 3, and the stabilization of the central wavelength of the AWG chip is realized by the temperature control circuit, and the operation principle is as follows: the AWG based on the silica-on-silicon material system has the wavelength temperature drift coefficient of 0.011nm/° C due to the thermo-optic effect of the material. In order to meet the wavelength precision requirement of +/-50 picometers in a commercial temperature or industrial temperature range, a heater or a Peltier (Peltier) refrigerator is controlled by a temperature control circuit, so that the AWG chip always works at a fixed set working temperature point. When the ambient temperature is lower than the temperature set by the temperature control circuit, the temperature control circuit outputs forward voltage to the heater or the Peltier (Peltier) refrigerator, the heater or the Peltier (Peltier) refrigerator is heated, the temperature of the chip is increased, and therefore the temperature of the chip can be stabilized at the set working temperature point; when the ambient temperature is higher than the temperature set by the temperature control circuit, the temperature control circuit outputs reverse voltage to a Peltier (Peltier) refrigerator, the refrigerator cools, and the temperature of the chip is reduced, so that the temperature of the chip can be stabilized at the set working temperature point. That is, the operating temperature of the AWG chip remains unchanged regardless of changes in the ambient temperature, so the output wavelength of the AWG remains unchanged.

In order to achieve temperature independent behavior of the AWG chip, i.e., the center wavelength of the AWG remains substantially unchanged as the ambient temperature changes, current commercial standards are such that the center wavelength of the AWG is shifted by less than 50pm over the commercial or industrial temperature range relative to the target wavelength specified by the ITU-T. In the prior art, a temperature control scheme shown in fig. 3 is adopted, a temperature control circuit is used for controlling a square entity to heat or refrigerate a main body 2, so that an AWG chip 1 works at a certain fixed temperature, and even if the environmental temperature changes, the temperature at the AWG chip is fixed, thereby achieving the purpose that the central wavelength of the AWG chip is stable and unchanged. It should be clear to those skilled in the art that: although the temperature at the temperature probing point of the temperature sensor remains unchanged, because the arrayed waveguide of the AWG chip is a region with a large area, the temperature gradient on the AWG arrayed waveguide is different when the ambient temperature changes; the square heating plate has larger size, the temperature field is not uniformly distributed, and the square heating plate has larger change along with the change of the environmental temperature; the AWG chip, the heating sheet and the bonding glue between the AWG chip and the heating sheet have different thermal expansions, and the thermal stress on the AWG chip changes along with the change of the environmental temperature. The AWG chip is a product with extremely sensitive temperature and stress, and the change of the temperature gradient, the change of the temperature field, and the change of the thermal stress are caused by the change of the environmental temperature, so that the central wavelength of the AWG chip in the commercial or industrial temperature range in the prior art can only be controlled at about 50pm, and the large wavelength shift further affects many optical indexes of the AWG, thereby reducing the yield of the product and affecting the product cost.

In order to solve the technical problems and further improve the performance of products, the invention provides a low-power-consumption high-efficiency heating or refrigerating method, wherein a C-shaped heating sheet shown in figure 4 is adopted to match a C-shaped AWG chip, the size of the heating sheet is greatly reduced by the C-shaped heating sheet, and the temperature gradient of the heating sheet is greatly reduced; the C-shaped heating plate greatly reduces the size of the heating plate, so that the thermal stress variation on the chip is also greatly reduced; the 'C' -shaped heating plate can reduce the mass of the heating plate to about 1/3 of the original mass, and the heating assembly can reach the set fixed temperature more quickly.

In the heating assembly and the figure 5, the temperature control circuit controls the C-shaped heating or refrigerating component 3 to make the AWG waveguide chip 1 work at a certain fixed temperature, even if the environmental temperature changes, the temperature of the AWG chip is fixed, thereby achieving the purpose that the central wavelength of the AWG is stable and unchanged. According to engineering experiments of long-term product development, the C-shaped heating or refrigerating component 3 adopted in the technical scheme provided by the invention has small temperature gradient change, small thermal stress change and small heating plate mass brought by the small size analyzed above. The change of the central wavelength of the AWG along with the change of the environmental temperature can be reduced to be within 30pm from 50pm due to small temperature gradient change and small thermal stress change, and the deviation of the central wavelength enables almost all indexes of the AWG, such as maximum insertion loss, non-adjacent crosstalk, total crosstalk, central wavelength precision, working temperature range, polarization related loss, channel insertion loss flatness and the like, to be optimized and improved, so that the product performance and the product yield can be greatly improved; the mass of the heating piece is greatly reduced, so that the temperature stabilization time of the AWG at room temperature is reduced from 3-4 minutes to about 1 minute, and the temperature stabilization time at low temperature is reduced from 6-9 minutes to about 3 minutes.

Although the present invention is described with respect to AWG as a specific embodiment, specific applications include, but are not limited to, optical splitters (Splitter), arrayed Waveguide Gratings (AWG), mach-zehnder interferometers (MZI), variable Optical Attenuators (VOA) and arrays, optical Switches (OS) and arrays, multicast switching optical switches (MCS), optically tunable wavelength division multiplexing/demultiplexing (VMUX), reconfigurable optical add-drop multiplexers (ROADM), differential quadrature phase-shift keying (DQPSK) demodulators, mixers (Co-Mixer), and so on.

Although the present invention is illustrated with specific examples of AWGs that are silica-on-silicon material systems, the material systems of the components to be heated or cooled include, but are not limited to, silicon dioxide, silicon nitride, silicon oxynitride, polymers, lithium niobate, iii-v cluster (InGaAsP), and the like.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (5)

1. A low-power-consumption high-efficiency heating or refrigerating method comprises a heating or refrigerating part, and is characterized in that the heating or refrigerating part is formed into a C-shaped or other special-shaped structure by removing redundant parts on the basis of square or sheet.

2. The method according to claim 1, wherein the heating or cooling component is made of at least one of silicon, silicon dioxide, silicon nitride, silicon oxynitride, polymer, lithium niobate, and III-V clusters.

3. The low-power-consumption high-efficiency heating or cooling method according to claim 1 or 2, wherein the method is applied to one or more of optical splitters, arrayed waveguide gratings, mach-Zehnder interferometers, variable optical attenuators and arrays, optical switches and arrays, multicast switching optical switches, optically tunable wavelength division multiplexing/demultiplexing devices, reconfigurable optical add/drop multiplexers, differential quadrature phase shift keying demodulators and mixers.

4. The low-power-consumption high-efficiency heating or refrigerating method according to claim 3, wherein the arrayed waveguide grating comprises a C-shaped heating or refrigerating component (3), the C-shaped heating or refrigerating component (3) is provided with a C-shaped AWG waveguide chip (1), and the outer edge of the C-shaped heating or refrigerating component (3) is arranged on the outer side of the AWG waveguide chip (1).

5. A low power consumption high efficiency heating or cooling method as claimed in claim 4, characterized in that the "C" shaped heating or cooling part (3) is connected to a temperature control circuit to make the AWG waveguide chip (1) work at a certain fixed temperature.

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