Optical power adjustable wavelength division multiplexer with power down protection

Abstract

The application provides a power adjustable wavelength division multiplexer with power-off protection function, which aims to solve the technical problem that the existing power adjustable wavelength division multiplexer does not have power-off alarm function, so that the optical network cannot realize automatic switching protection, timely fault positioning and fault recovery. The application comprises an array waveguide grating module group, a variable optical attenuator array module group and a circuit controller module group, the circuit controller module group is connected with the variable optical attenuator array module group, the circuit controller module group is provided with a VOA controller and an OS controller, the VOA controller is connected with the variable optical attenuator array module group, the OS controller is connected with an optical switch module group, and the optical switch in the optical switch module group works in a closed state when not powered and works in an open state when powered. The optical switch of the application is in a closed state, and the optical power is abnormal, so that the power adjustable wavelength division multiplexer has power-off protection function.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, and more particularly to an optical power adjustable wavelength division multiplexer with power-down protection function. It is an integrated optical device with power-down protection function, and particularly relates to fault detection, location, notification and fault recovery. Background Technology

[0002] The combination of erbium-doped fiber amplifiers (EDFAs) and dense wavelength division multiplexing (DWDM) technology has become the main means of high-speed and high-capacity optical fiber communication. However, due to the uneven gain spectrum of EDFAs, the gains of several different wavelength signals amplified and transmitted by EDFAs in a DWDM system are inconsistent. Moreover, with the cascading of multiple EDFAs in long-distance communication systems, this gain unevenness accumulates, causing uneven power distribution across channels (wavelengths) and leading to dynamic imbalance in the system. In addition, when the number of channels increases or decreases, or when the power of a certain channel changes, it can also cause power jumps in other channels, resulting in different optical power values ​​and optical signal-to-noise ratios (OSNR) received by each channel at the receiver. This imbalance is very detrimental to the transmission performance of the entire system, often causing crosstalk between signals and causing the bit error rate (EBR) of some wavelength channels to exceed the specified value. If the unbalanced power value is too high, it will cause nonlinear effects in the optical signal transmission through the optical fiber, and the received optical power value will exceed the receiver's maximum dynamic range; if the unbalanced power value is too low, the received optical power value will be lower than the receiver's sensitivity, resulting in the inability to receive the optical signal, and many other adverse effects. In order to achieve long-distance, high-speed, error-free transmission of optical signals in a DWDM system, the optical power of each channel must be equalized.

[0003] An optical power adjustable wavelength division multiplexer (VMUX) is a channel optical power pre-equalization and multiplexing module. It features multiplexing and pre-equalization of optical power for each channel, and can adjust the optical attenuation between input and output under circuit control. It actively reports alarm information, performs relevant operations according to network management requirements, and reports relevant information. The VMUX structure is as follows: Figure 1 As shown, it mainly consists of three main module groups: Arrayed Waveguide Grating (AWG) module group A, Variable Optical Attenuator (VOA) array module group B, and Circuit Controller module group C. Arrayed Waveguide Grating (AWG) module group A includes the AWG chip F, such as... Figure 2 As shown, the AWG chip uses a heater or Peltier cooler G and a temperature sensor E, and achieves constant temperature operation through the AWG's temperature control circuit; the variable optical attenuator (VOA) array module group B, such as Figure 3 As shown, a heater or Peltier cooler G and a temperature sensor E are also used, and constant temperature operation is achieved through the VOA temperature control circuit.

[0004] Figure 1 The existing optical power adjustable wavelength division multiplexer (WDM) solution shown lacks an unexpected power outage alarm function. Communication between the VMUX and the network management system relies on the circuitry; however, in the event of a power outage, the communication circuitry loses power and cannot upload alarm information. The network management system, not receiving alarm information, mistakenly believes the module is functioning normally. Since the VMUX operates on the trunk line, a fault there would have a significant impact on services. Therefore, fault detection, location, notification, and alarm functions are urgently needed for optical network fault recovery and automatic switching protection of fiber optic lines. Summary of the Invention

[0005] To address the technical problem that existing optical power adjustable wavelength division multiplexers lack an unexpected power outage alarm function, thus preventing optical networks from achieving automatic switching protection, timely fault location, and fault recovery, this invention proposes an optical power adjustable wavelength division multiplexer with power outage protection function, providing a solution for fault location and recovery in optical networks.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: an optical power adjustable wavelength division multiplexer with power-down protection function includes an arrayed waveguide grating module group, a variable optical attenuator array module group, and a circuit controller module group. The circuit controller module group is connected to the variable optical attenuator array module group. The circuit controller module group is equipped with a VOA controller and an OS controller. The VOA controller is connected to the variable optical attenuator array module group, and the OS controller is connected to the optical switch module group. The optical switch in the optical switch module group operates in the off state when no power is applied and in the on state when power is applied.

[0007] Preferably, the circuit controller module group and the RS232 communication interface are connected to the client control module.

[0008] Preferably, the arrayed waveguide grating module group includes an AWG chip, and the AWG chip has a heat-free encapsulation portion on its outer side.

[0009] Preferably, the circuit controller module group includes an AWG controller, which is connected to the arrayed waveguide grating module group; the arrayed waveguide grating module group includes an AWG chip, a heater or Peltier cooler is provided on the outside of the AWG chip, and a temperature sensor is provided on the AWG chip.

[0010] Preferably, the variable optical attenuator array module group includes a VOA chip, and the VOA chip is equipped with a temperature sensor.

[0011] Preferably, the VOA chip is equipped with a heater or a Peltier cooler.

[0012] Preferably, the heat-free encapsulation portion is one of the following: a planar waveguide moving / rotating scheme, an input waveguide moving scheme, a planar waveguide polymer filling scheme, or an array waveguide polymer filling scheme.

[0013] Preferably, the input planar waveguide or output planar waveguide of the AWG chip is cut along the cutting line to form two parts. The two parts are respectively fixed to the moving part I or the moving part II of the heat-free packaged part. A temperature driver is fixed between the side ends of the moving part I and the moving part II. The two cut parts can move relative to each other as the temperature changes through the temperature compensator, which compensates for the wavelength drift caused by the temperature, so that the center wavelength of the AWG chip does not change with the ambient temperature.

[0014] Preferably, the working principle of the arrayed waveguide grating module group and the variable optical attenuator array module group is as follows: the microcontrollers of the AWG controller and VOA controller in the circuit controller module group set a constant operating temperature T0, the temperature sensor measures the actual temperature T1 in real time, the microcontroller calculates the difference between temperature T1 and temperature T0, and controls the magnitude and / or direction of the voltage or current applied to the heater or Peltier cooler through the temperature feedback PID control algorithm stored in the microcontroller, so that it heats / does not heat or cools, thereby making it always work at a constant set operating temperature T0.

[0015] Preferably, the microcontroller of the VOA controller in the circuit controller module group is equipped with a lookup table, which contains the correspondence between the attenuation of VOA at different temperatures, different input voltages or currents.

[0016] The beneficial effects of this invention are as follows: After an unexpected power outage in the optical power adjustable wavelength division multiplexer, the circuit cannot report the abnormal power outage, but the optical switch of this invention remains in the off state, resulting in abnormal optical power and thus providing power-down protection. This invention includes an optical switch (OS) module group that remains in the off state during power outages and has a power-down retention function; after a power outage, the output optical power drops sharply, thereby providing an alarm function from the optical path; the technical solution of this invention provides a solution for fault location and recovery in optical networks. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of an existing optical power adjustable wavelength division multiplexer.

[0019] Figure 2 This is a schematic diagram of the AWG section of an existing optical power adjustable wavelength division multiplexer.

[0020] Figure 3 This is a schematic diagram of the VOA section of an existing optical power adjustable wavelength division multiplexer.

[0021] Figure 4 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0022] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0023] Figure 6 This is a schematic diagram of the structure of the arrayed waveguide grating module group of the present invention.

[0024] Figure 7 This is a schematic diagram of the structure of the variable optical attenuator array module group of the present invention.

[0025] Figure 8 This is a schematic diagram of the structure of a heat-free encapsulated part of an AWG that is disclosed in the prior art.

[0026] Figure 9 This is a schematic diagram of a publicly disclosed AWG heatless encapsulation solution.

[0027] In the diagram, A - Arrayed Waveguide Grating (AWG) module group; B - Variable Optical Attenuator (VOA) array module group; C - Circuit Controller (Module Controller) module group; D - Optical Switch (OS) module group; E - Temperature sensor; F - AWG chip; G - Heater or Peltier cooler; H - VOA chip; I - AWG heatless packaged part; 1-1 is moving part I; 1-2 is moving part II; 1-3 is rotating connecting shaft; 1-4 is lug I; 1-5 is lug II; 2 - Temperature driver; 4 and 5 are the fixing points between the temperature driver and the base plate; 6 - Cutting line on the AWG chip; D1 and D2 - Two parts formed after the AWG chip is cut along cutting line 6. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The existing VMUX only has an Arrayed Waveguide Grating (AWG) module group A, a Variable Optical Attenuator (VOA) array module group B, and a circuit controller module group C. Circuit controller module group C includes a VOA controller and an AWG controller. The VOA controller is connected to the AWG module group A, and the AWG controller is connected to the VOA array module group B. Both AWG module group A and VOA array module group B can only function normally through the control of circuit controller module group C. In the event of an unexpected power outage, since the VOA operates with minimal attenuation when no power is applied, this could lead to excessive optical power in the optical communication link, damaging the equipment in the link. To address this safety hazard caused by unexpected power outages, this invention proposes adding an optical switch (OS) module group D to implement the VMUX's power-down protection function. The optical switch's function is to open and close the optical path. The optical switch in this invention is designed to operate in the off state when no power is applied and has a power-down retention function, meaning it remains in the off state when power is lost and operates in the on state when power is applied. In this way, when an unexpected power outage occurs, the optical switch is not powered on, and the optical path is in an off state. Thus, there is no optical power in the communication link, thereby realizing the function of power failure protection.

[0030] Example 1

[0031] An optical power adjustable wavelength division multiplexer with power-down protection, such as Figure 4As shown, the system includes an arrayed waveguide grating module group A, a variable optical attenuator array module group B, a circuit controller module group C, and an optical switch module group D. Both the variable optical attenuator array module group B and the optical switch module group D are connected to the arrayed waveguide grating module group A. The circuit controller module group C includes a VOA controller, an AWG controller, and an OS controller. The VOA controller is connected to the variable optical attenuator array module group B, and its function is to send commands to the VOA chip H to control the attenuation of the VOA. The AWG controller is connected to the arrayed waveguide grating module group A, and its function is to send commands to the AWG chip F to control the operating temperature of the AWG. The optical switch (OS) module group D is in the off state when powered off and has a power-off retention function. After the optical switch (OS) module group D is powered off, the output optical power drops sharply, thus providing an alarm function from the optical path. The OS controller is connected to the optical switch module group D, and its function is to send commands to the optical switch OS to control the opening and closing of the optical switch OS. Both the arrayed waveguide grating module group A and the variable optical attenuator array module group B have temperature control circuits for temperature control. The optical switch in the optical switch module group D operates in the off state when no power is applied and in the on state when power is applied. The circuit controller module group C is connected to the client control module via an RS232 communication interface. The client control module communicates with the optical power adjustable wavelength division multiplexer (WDM) and controls the operating state of the WDM according to the customer's actual application requirements.

[0032] Among them, such as Figure 2 As shown, the arrayed waveguide grating module group A includes an AWG chip F. A heater or Peltier cooler G is used on the outside of the AWG chip F to heat or cool it. A temperature sensor E is installed inside the AWG chip to detect its temperature. The AWG controller in module group C achieves constant temperature operation for the arrayed waveguide grating module group A. The variable optical attenuator (VOA) array module group B includes a VOA chip H, such as... Figure 3As shown, the VOA chip H is equipped with a heater or Peltier cooler G and a temperature sensor E. The constant temperature operation of the variable optical attenuator (VOA) array module B is achieved through the VOA controller in the circuit controller module group C. The working principle of the array waveguide grating module group A and the variable optical attenuator (VOA) array module group B is as follows: The microcontrollers of the AWG controller and the VOA controller in the circuit controller module group C are set to a constant operating temperature T0. The temperature sensor E constantly feeds back the actual temperature T1 of the VMUX. The microcontroller constantly calculates the difference between temperature T1 and temperature T0. Through the temperature feedback PID (proportional, integral, derivative) control algorithm stored in the microcontroller, it controls the magnitude and / or direction of the voltage or current applied to the heater or Peltier cooler G, so that it heats / does not heat or cools, thereby ensuring that the VMUX always operates at a constant set operating temperature T0, thus achieving stable and normal operation of the VMUX. If the actual temperature T1 is greater than the operating temperature T0, no voltage is applied to the heater G, and the temperature naturally drops to the operating temperature T0 through heat dissipation. Alternatively, a reverse voltage or current is applied to the Peltier cooler G to cool the VMUX, thereby lowering the temperature to the operating temperature T0. If the actual temperature T1 is less than the operating temperature T0, electricity is applied to the heater G to heat the temperature to the operating temperature T0, or a forward voltage or current is applied to the Peltier cooler G to heat the temperature to the operating temperature T0. The constant operating temperature T0 of the arrayed waveguide grating module group A and the variable optical attenuator (VOA) array module group B can be set separately and can be different.

[0033] Example 2

[0034] An optical power adjustable wavelength division multiplexer with power-down protection function, differing from Embodiment 1, in that the circuit controller module group C includes a VOA controller and an OS controller. The VOA controller is connected to the arrayed waveguide grating module group A, and the OS controller is connected to the optical switch module group D, as shown below. Figure 5 As shown. Figure 6 As shown, the arrayed waveguide grating module group A has no heater or Peltier cooler, requires no power, and does not require temperature control circuitry, employing the heat-free packaging solution from patent 201810428523.4. Figure 7 As shown, the Variable Optical Attenuator (VOA) array module group B has no heater or Peltier cooler, only a temperature sensor E. The applied voltage or current can be controlled by the VOA controller in the circuit controller module group C, thereby realizing the low power consumption and high reliability characteristics of VMUX.

[0035] The technical solution proposed in this invention includes an arrayed waveguide grating module group A comprising an AWG chip F, wherein the AWG chip F is disposed on the heat-free packaged portion I, as shown below. Figure 6 As shown, there is no heater or Peltier cooler, no temperature sensor, no need for power, no need for temperature control circuit, only AWG chip F and heatless package I. The heatless package solution in patent 201810428523.4 is used as an example for illustration. For specific details, please refer to the relevant patent.

[0036] like Figure 8 As shown, the heat-free packaged portion I of the AWG chip F disclosed in patent 201810428523.4 includes a base plate 1 and a temperature actuator 2. The base plate 1 includes a movable part I1-1, a movable part II1-2, and a rotating connecting shaft 1-3. A gap is provided between the movable parts I1-1 and II1-2, and the rotating connecting shaft 1-3 is disposed within the gap and connects the movable parts I1-1 and II1-2 together. A lug I1-4 is provided on the side end of the movable part I1-1, and a lug II1-5 is provided on the side end of the movable part II1-2. The lugs I1-4 and II1-5 correspond to each other. The temperature actuator 2 is installed between the lugs I1-4 and II1-5, and the coefficient of thermal expansion of the base plate 1 and the coefficient of thermal expansion of the temperature actuator 2 are different. The temperature actuator and the base plate are two relatively independent entities. The temperature actuator is fixed to the base plate by mechanical means, welding, or adhesive.

[0037] The heat-free packaging solution for AWG disclosed in patent 201810428523.4, such as... Figure 9 As shown, if the input or output planar waveguide of the AWG chip F is cut along the cutting line 6, the cutting line 6 can be set at any position of the input or output planar waveguide of the AWG to form two parts, D1 and D2. The temperature compensator 2 enables the two cut parts to move relative to each other as the temperature changes, thus compensating for the wavelength drift caused by temperature, so that the center wavelength of the AWG chip F does not change with the ambient temperature.

[0038] The technical solution proposed in this invention includes a variable optical attenuator (VOA) array module group B, such as... Figure 7 As shown, there is no heater or Peltier cooler, only a temperature sensor E. The AWG module group A in the specific embodiment of this invention uses a heatless encapsulation part I, which is only illustrated by the heatless encapsulation scheme in patent 201810428523.4, including but not limited to: planar waveguide movement / rotation, input waveguide movement, planar waveguide polymer filling, array waveguide polymer filling, and other disclosed technical solutions.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An optical power adjustable wavelength division multiplexer with power-down protection function, comprising an arrayed waveguide grating module group (A), a variable optical attenuator array module group (B), and a circuit controller module group (C), wherein the circuit controller module group (C) is connected to the variable optical attenuator array module group (B), characterized in that, The circuit controller module group (C) is internally provided with a VOA controller and an OS controller, the VOA controller is connected with the variable optical attenuator array module group (B), the OS controller is connected with the optical switch module group (D), the optical switch module group (D) is connected with the arrayed waveguide grating module group (A), the optical switch in the optical switch module group (D) works in the closed state when not powered, when power failure occurs, the optical switch is not powered, the optical path is in the closed state, there is no optical power in the communication link, the function of power failure protection is achieved, the working state is kept in the closed state when power failure occurs, the working state is in the open state when powered. The circuit controller module group (C) is connected with the client control module through an RS232 communication interface. The circuit controller module group (C) is internally provided with an AWG controller, and the AWG controller is connected with the arrayed waveguide grating module group (A).

2. The optical power tunable wavelength division multiplexer having power down protection function according to claim 1, wherein, The arrayed waveguide grating module group (A) comprises an AWG chip (F), and the AWG chip (F) is externally provided with a non-thermal packaging part (I).

3. The optical power tunable wavelength division multiplexer having power down protection function according to claim 1, wherein, The arrayed waveguide grating module group (A) comprises an AWG chip (F), and the AWG chip (F) is externally provided with a heater or a Peltier cooler, and the AWG chip (F) is provided with a temperature sensor.

4. The optical power tunable wavelength division multiplexer having power down protection function according to claim 2 or 3, characterized by, The variable optical attenuator array module group (B) comprises a VOA chip (H), and the VOA chip (H) is provided with a temperature sensor.

5. The optical power tunable wavelength division multiplexer with power down protection function according to claim 3, wherein, The variable optical attenuator array module group (B) comprises a VOA chip (H), and the VOA chip (H) is provided with a heater or a Peltier cooler.

6. The optical power tunable wavelength division multiplexer with power down protection function according to claim 2, wherein, The non-thermal packaging part (I) is one of a flat waveguide moving / rotating scheme, an input waveguide moving scheme, a flat waveguide polymer filling scheme or an array waveguide polymer filling scheme.

7. The optical power tunable wavelength division multiplexer with power-down protection function according to claim 2 or 6, wherein, The middle part of the input flat waveguide or the output flat waveguide of the AWG chip (F) is cut along a cutting line (6) to form two parts, the two parts are respectively arranged to be fixed on a moving part I (1-1) or a moving part II (1-2) of the non-thermal packaging part (I), and a temperature driver (2) is fixed between the side ends of the moving part I (1-1) and the moving part II (1-2), so that the two cut parts can relatively move with the change of temperature through the temperature compensator (2), the wavelength drift caused by temperature is compensated, and thus the center wavelength of the AWG chip (F) does not change with the ambient temperature.

8. The optical power tunable wavelength division multiplexer with power down protection function according to claim 3, wherein, The working principle of the arrayed waveguide grating module group (A) and the variable optical attenuator array module group (B) is that the single-chip microcomputer of the AWG controller and the VOA controller in the circuit controller module group (C) sets a constant working temperature T0, the temperature sensor measures the actual temperature T1 in real time, the single-chip microcomputer calculates the difference between the temperature T1 and the temperature T0, controls the voltage or current size and / or direction of the heater or the Peltier cooler through the temperature feedback PID control algorithm stored in the single-chip microcomputer, so that the heater / is not heated or refrigerated, so that it always works at the constant set working temperature T0.

9. The optical power tunable wavelength division multiplexer with power-down protection function according to any one of claims 5, 6, 8, wherein, The single-chip microcomputer of the VOA controller in the circuit controller module group (C) is provided with a lookup table, and the lookup table is provided with a corresponding relationship between different input voltages or currents and the attenuation of the VOA at different temperatures.

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