KR20230108975A - Method for tuning wavelength of optical transceiver based on strength of optical signal and electronic device thereof - Google Patents

Abstract

The first optical transceiver according to an embodiment includes a transmitter optical sub-assembly (TOSA), a receiver optical sub-assembly (ROSA), a wavelength adjustment module, and the optical transmission element module, and a controller operatively coupled to the light receiving element module and the wavelength adjusting module, wherein the controller controls intensities of a plurality of optical signals corresponding to different wavelengths through the light receiving element module. Receive information indicating a , identify a change in intensity of the optical signal based on the received information, identify a wavelength that satisfies a specified condition based on the identified intensity change, and It may be configured to adjust the wavelength of the optical signal transmitted from the optical transmission element module based on the. Other embodiments are also possible.

Description

Method for adjusting the wavelength of an optical transceiver based on the strength of an optical signal and electronic device thereof

The descriptions below relate to a method for adjusting a wavelength of an optical transceiver based on an intensity of an optical signal and an electronic device thereof.

In order to process more data at a higher speed, the proportion of optical communication in networks is increasing. As the proportion of optical communication increases, the demand for an optical transceiver performing conversion between an electrical signal and an optical signal increases.

A wavelength division multiplexing-passive optical network (WDM-PON) technology uses optical signals of different wavelengths for each channel, and requires a wavelength locking technology. A conventional optical transceiver may fix the wavelength of an optical signal through a separate hardware component (eg, a wavelength locker) for fixing the wavelength. In this conventional wavelength fixing method, as a separate hardware for wavelength fixing is used in an optical transceiver that transmits an optical signal, the optical transceiver is bulky and has a high manufacturing cost. Therefore, a solution capable of fixing the wavelength of an optical signal while reducing the volume and manufacturing cost of the optical transceiver may be required.

A first optical transceiver according to an embodiment includes a transmitter optical sub-assembly (TOSA), a receiver optical sub-assembly (ROSA), a wavelength adjustment module, and the optical transmission module. An element module, the light receiving element module, and a controller operatively coupled to the wavelength adjustment module, wherein the controller comprises a plurality of lights corresponding to different wavelengths through the light receiving element module. Receiving information indicating the strength of a signal, identifying a change in intensity of an optical signal based on the received information, identifying a wavelength that satisfies a specified condition based on the identified change in intensity of the optical signal, and It may be configured to adjust the wavelength of the optical signal transmitted from the optical transmission device module based on the received wavelength.

The first optical transceiver according to an embodiment includes a transmitter optical sub-assembly (TOSA), a receiver optical sub-assembly (ROSA), a wavelength adjustment module, and the optical transmission element module, and a controller operatively coupled to the light receiving device module and the wavelength adjusting module, wherein the controller generates a plurality of optical signals corresponding to different wavelengths through the light receiving device module. Receiving information indicating the intensity, generating reference data based on the information indicating the intensity of the plurality of optical signals, and adjusting the wavelength of the optical signal transmitted through the optical transmission device module based on the reference data can be configured to

A method for adjusting a wavelength of an optical transceiver and an electronic device thereof according to an embodiment adjusts and fixes a wavelength of an optical signal without using separate hardware for wavelength fixing, and thus requires separate hardware for fixing the wavelength. The volume and manufacturing cost of the optical transceiver can be lowered than in the case of using the optical transceiver.

1 shows an environment including electronic devices that perform data communication over an optical network.
2A is a block diagram illustrating a first optical transceiver according to an exemplary embodiment.
2B is a block diagram illustrating a second optical transceiver according to an exemplary embodiment.
3 is a flowchart illustrating an example of a method of adjusting a wavelength in a first optical transceiver according to an embodiment.
4A and 4B are graphs for explaining an example of a method of adjusting a wavelength in a first optical transceiver according to an exemplary embodiment.
5 is a flowchart illustrating another example of a method of adjusting a wavelength in a first optical transceiver according to an exemplary embodiment.
6 is a graph for explaining another example of a method of adjusting a wavelength in a first optical transceiver according to an embodiment.
7 is a flowchart illustrating a method of generating feedback information in a second optical transceiver according to an exemplary embodiment.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in this specification are only illustrated for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention These may be embodied in various forms and are not limited to the embodiments described herein.

Embodiments according to the concept of the present invention can apply various changes and can have various forms, so the embodiments are illustrated in the drawings and described in detail herein. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosures, and includes modifications, equivalents, or substitutes included in the spirit and scope of the present invention.

Terms such as first or second may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component, for example, without departing from the scope of rights according to the concept of the present invention, a first component may be named a second component, Similarly, the second component may also be referred to as the first component.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle. Expressions describing the relationship between components, such as "between" and "directly between" or "directly adjacent to" should be interpreted similarly.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that an embodied feature, number, step, operation, component, part, or combination thereof exists, but one or more other features or numbers, It should be understood that the presence or addition of steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this specification, it should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, the scope of the patent application is not limited or limited by these examples. Like reference numerals in each figure indicate like elements.

1 shows an environment including electronic devices that perform data communication over an optical network.

According to an embodiment, the optical network of FIG. 1 may include an optical network to which electronic devices disposed in different regions are connected based on one or more optical lines 130 . The optical network may include, for example, a passive optical network (PON).

Referring to FIG. 1, a first electronic device (eg, a digital unit (DU) or a central office terminal (COT)) 110 included in an optical network and a second electronic device (eg, a radio unit (RU), RRH ( An example in which a remote radio head (RRU) or remote radio unit (RRU) 150 is connected based on the optical line 130 is shown. An optical network including the first electronic device 110 and the second electronic device 150 may correspond to, for example, at least a part of a 5G fronthaul. However, it is not limited thereto. For example, an optical line terminal (OLT) and/or an optical network unit (ONU) may be connected to each other based on the optical line 130 .

According to an embodiment, the first electronic device 110 and/or the second electronic device 150 may include one or more electronic devices according to various embodiments. For example, the first electronic device 110 includes k first optical transceivers 101-1, ..., 101-k, and the second electronic device 150 includes k second optical transceivers. (101-k+1, ..., 101-2k) may be included.

According to one embodiment, the first optical transceiver 101-1, ..., or 101-k is configured to perform conversion between an optical signal and an electrical signal, transmit an electrical signal, and/or electrically support a scene. interface 115 and an optical interface 125 to support transmission and/or reception of optical signals. Electrical interface 115 may include, for example, one or more pins, electrodes, and/or wires transmissible to electrical signals based on a specified communication protocol, such as an I2C protocol. Optical interface 125 may include, for example, one or more optical ports for coupling to one or more optical fibers.

According to one embodiment, the first optical transceiver 101-1, ..., or 101-k is a first multiplexer and demultiplexer device (MUX/DEMUX device) included in the optical network through the optical interface 125. (120). The first multiplexer and demultiplexer device 120 performs optical multiplexing and/or demultiplexing based on a thin film filter (TFF), and may have a passband assigned to each access port. Optical ports extending from the first multiplexer and demultiplexer device 120 may transmit and receive optical signals of different wavelengths.

According to an embodiment, the second optical transceiver 101-k+1, ..., or 101-2k is configured to perform conversion between an optical signal and an electrical signal, transmit an electrical signal, and/or support a scene. and an optical interface 145 for supporting transmission and/or reception of an optical signal. The electrical interface 155 may include one or more pins, electrodes, and/or wires transmissible for electrical signals based on a specified communication protocol, such as, for example, an I2C protocol. Optical interface 145 may include, for example, one or more optical ports for coupling to one or more optical fibers.

According to one embodiment, the second optical transceiver (101-k+1, ..., or 101-2k) is a second multiplexer and demultiplexer device (MUX/DEMUX) included in the optical network through the optical interface 145. device) (140). The second multiplexer and demultiplexer device 140 performs optical multiplexing and/or demultiplexing based on a thin film filter, and may have a passband assigned to each access port. The optical ports extending from the second multiplexer and demultiplexer device 140 may transmit and receive optical signals of different wavelengths.

According to an embodiment, the first and second multiplexer and demultiplexer devices 120 and 140 may change a path through which an optical signal propagates in an optical network based on Wavelength Division Multiplexing (WDM). . For example, a plurality of optical signals having different wavelengths transmitted by the plurality of first optical transceivers 101-1, ..., 101-k are multiplexed in the first multiplexer and demultiplexer device 120, It may propagate along the optical line 130 . The multiplexed optical signals may be demultiplexed in the second multiplexer and demultiplexer device 140 and distributed to the plurality of second optical transceivers 101-k+1, ..., 101-2k. For another example, the plurality of optical signals having different wavelengths transmitted by the plurality of second optical transceivers 101-k+1, ... , 101-2k are transmitted by the second multiplexer and demultiplexer device 140 It can be multiplexed in and propagated along the optical line 130. The multiplexed optical signals may be demultiplexed in the first multiplexer and demultiplexer device 120 and distributed to the plurality of first optical transceivers 101-1, ..., 101-k.

2A is a block diagram illustrating a first optical transceiver according to an exemplary embodiment. Hereinafter, a module, unit, and/or circuit may mean a set of one or more circuit elements of the first optical transceiver and the second optical transceiver of FIGS. 2A to 2B .

Referring to FIG. 2A , the first optical transceiver 200 includes a controller 210, a wavelength control module 211, a transmitter optical sub-assembly (TOSA) 220, and a receiver module. optical sub-assembly (ROSA) 230 , a first amplifier 231 , a second amplifier 233 , and a connector 240 . However, it is not limited thereto. For example, the first optical transceiver 200 may further include components other than the components described above.

According to one embodiment, the controller 210 may process data based on one or more instructions. The controller 210 may include, for example, an Arithmetic and Logic Unit (ALU), a Field Programmable Gate Array (FPGA), and/or a Central Processing Unit (CPU).

According to one embodiment, the controller 210 may include a memory for storing input and/or output data and/or instructions. The memory may be included in the controller 210 in the form of a system-on-chip (SoC) or disposed on a printed circuit board (PCB) of the first optical transceiver 200 together with the controller 210 . The memory may include, for example, volatile memory such as random-access memory (RAM) and/or non-volatile memory such as read-only memory (ROM). The volatile memory may include, for example, at least one of Dynamic RAM (DRAM), Static RAM (SRAM), Cache RAM, and Pseudo SRAM (PSRAM). The nonvolatile memory may include, for example, at least one of a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a flash memory, a hard disk, a compact disk, and an embedded multi media card (eMMC). can

According to an embodiment, the light transmitting element module 220 may output an optical signal based on a control signal of the controller 210 . The light transmitting element module 220 may include a laser diode (LD) for generating an optical signal. The laser diode may include, for example, a fabric perot LD (FP-LD), a distributed feedback LD (DFB-LD), a distributed bragg reflector LD (DBR-LD), an external cavity laser (ECL), and/or a vertical cavity laser (VCSEL). surface emitting laser). According to an embodiment, the laser diode may include a tunable LD in which a wavelength of an output optical signal is adjusted based on voltage, current, and/or temperature. According to an embodiment, the control signal transmitted from the controller 210 may be amplified by the first amplifier 231 and then provided to the light transmitting element module 220 .

According to an embodiment, the wavelength adjustment module 211 may adjust the wavelength of an optical signal output from the optical transmission device module 220 based on a control signal of the controller 210 . For example, the wavelength adjustment module 211 adjusts the amplitude and/or frequency of the voltage and/or current input to the optical transmission element module 220, thereby outputting the output from the optical transmission element module 220. The wavelength of the optical signal can be adjusted. In this case, the wavelength adjustment module 211 may include an oscillator and/or a modulator. For another example, the wavelength control module 211 may adjust the wavelength of the optical signal output from the light transmission module 220 by adjusting the temperature of the light transmission element module 220. In this case, the wavelength adjustment module 211 may include a thermistor and/or a thermo-electric cooler (TEC). According to an embodiment, the wavelength adjustment module 211 may adjust the wavelength of the optical transmission element module 220 to a value smaller than a wavelength range in which the intensity of the optical signal becomes constant (or maximum).

According to an embodiment, the light receiving element module 230 may receive an optical signal provided from an optical network. The light receiving element module 230 may output an electrical signal corresponding to the received optical signal. An electrical signal output from the light receiving element module 230 may be amplified by the second amplifier 233 and then provided to the controller 210 and the connector 240 . According to an embodiment, the light receiving element module 230 may include a photodiode (PD) to output an electrical signal corresponding to the optical signal. The photodiode may include, for example, a P-I-N PD (PIN-PD) and an avalanche PD (APD).

According to an embodiment, the connector 240 is an electrical interface (eg, the electrical interface 115 of FIG. 1 ), and the first optical transceiver 200 and another electronic device (eg, the first electronic device 110 of FIG. 1 ). )) can support electrical coupling between them.

According to an embodiment, the controller 210 may transmit a plurality of optical signals corresponding to different wavelengths through the optical transmission element module 220 . For example, the controller 210 transmits the first optical signal of the first wavelength through the light transmission element module 220, and after a specified time, through the light transmission element module 220, the first optical signal different from the first wavelength is transmitted. A second optical signal of two wavelengths may be transmitted, and a third optical signal of a third wavelength different from the first and second wavelengths may be transmitted through the optical transmission device module 220 after a designated time.

According to an embodiment, the controller 210 may receive information indicating the strength of an optical signal through the light receiving element module 230 . For example, the controller 210 transmits light from the second optical transceiver (eg, the second optical transceiver 101-k+1, ... , or 101-2k of FIG. 1) through the light receiving element module 230. When the signal is received, a subcarrier signal may be obtained from the optical signal by using a filter (eg, a low pass filter). The controller 210 demodulates the subcarrier signal to obtain an optical signal (eg, a first Information indicating the intensity of the optical signal, the second optical signal, and/or the third optical signal) can be obtained.

According to an embodiment, the controller 210 may identify a change amount of the intensity of the optical signal based on information indicating the intensity of the plurality of optical signals. For example, the controller 210 may identify the amount of change in intensity of a plurality of optical signals based on information indicating the intensities of the plurality of optical signals. Specifically, the controller 210 identifies intensity variations between the first and second optical signals based on the information indicating the intensity of the first optical signal and the information indicating the intensity of the second optical signal, and Intensity variations of the second and third optical signals may be identified based on the information indicating the intensity of the optical signal and the information indicating the intensity of the third optical signal.

According to an embodiment, the controller 210 may identify a wavelength that satisfies a specified condition in response to identifying the amount of change in intensity of the optical signal. The controller 210 converts the wavelength corresponding to the point where the intensity of the optical signal becomes flat (or the first point where the intensity of the optical signal has the maximum value) to a wavelength that satisfies a specified condition by continuously monitoring the amount of change in the intensity of the optical signal. can decide For example, the controller 210 may output light from the second wavelength when the intensity variation between the first and second optical signals is equal to or greater than the reference variation and the intensity variation between the second and third optical signals is less than the reference variation. It is determined that the intensity of the signal is constant, and the second wavelength may be determined as a wavelength that satisfies a specified condition. The controller 210 transmits a plurality of optical signals of different wavelengths after adjusting the wavelength when a wavelength satisfying a specified condition is not identified (or when a section having a constant optical signal intensity is not identified). action can be repeated.

According to an embodiment, the controller 210 may adjust the wavelength of the light transmitting element module 220 in response to determining the designated wavelength. For example, the controller 210 obtains a fourth wavelength obtained by applying a specified value to a wavelength that satisfies a specified condition, and adjusts the wavelength so that the wavelength of the optical signal output from the optical transmission device module 220 becomes the fourth wavelength. The module 211 can be controlled.

According to an embodiment, the controller 210 may generate reference data based on information indicating intensities of a plurality of optical signals. For example, the controller 210 loads previously stored information on the intensity of optical signals according to wavelengths from a memory (not shown), and based on the information indicating the intensities of a plurality of optical signals, the information loaded from the memory is loaded. By correcting the information, reference data can be obtained. For another example, the controller 210 may generate reference data by generating intensity information of the optical signal according to wavelengths from information indicating the intensity of the optical signal using interpolation. According to an embodiment, the reference data may include parameters in Table 1 below.

TEC temperature setting value Data matching wavelength information according to TEC temperature TEC temperature range value TEC temperature variable interval when finding the center wavelength Target channel center wavelength Center wavelength of target channel Receive light input intensity (or power) strength of the light signal TEC temperature range value TEC temperature variable interval when finding the center wavelength Receive light input intensity (or intensity) slope The slope value of the two wavelength points

According to an embodiment, the controller 210 may adjust the wavelength of an optical signal output through the optical transmission device module 220 based on reference data. For example, the controller 210 may identify a section in which the intensity of the optical signal is maximized based on the reference data. The controller 210 controls the optical transmission element module 220 through the wavelength adjustment module 211 so that the intensity of the optical signal output through the optical transmission element module 220 is included within a section in which the intensity of the optical signal is maximized. ), it is possible to adjust the wavelength of the optical signal output through.

As described above, the first optical transceiver 200 determines the wavelength of the optical signal output from the first optical transceiver 200 based on the feedback information of the second optical transceiver so that the intensity of the optical signal has the greatest value. can be adjusted When the intensity of the optical signal is the maximum value, information indicating a change in intensity is not received by the first optical transceiver 200, and thus, the wavelength of the first optical transceiver 200 may be fixed. The above-described first optical transceiver 200 does not require additional hardware for monitoring the wavelength of the optical signal output through the optical transmission device module 220, and the wavelength of the optical signal output through the optical transmission device module 220. Since it is adjusted and fixed, it has a smaller volume than an optical transceiver that uses separate hardware for monitoring the wavelength of an optical signal output through the optical transmission element module 220, and it is possible to reduce the production cost by saving hardware cost. .

2B is a block diagram illustrating a second optical transceiver according to an exemplary embodiment.

Referring to FIG. 2B , the second optical transceiver 250 includes a controller 251, a light intensity detection module 253, an optical transmission element module 260, an optical reception element module 270, and a first amplifier 271. , a second amplifier 273, and a connector 280. However, it is not limited thereto. For example, the second optical transceiver 250 may further include components other than the above-described components.

According to one embodiment, the controller 251 may process data based on one or more instructions. The controller 251 may include, for example, an Arithmetic and Logic Unit (ALU), a Field Programmable Gate Array (FPGA), and/or a Central Processing Unit (CPU).

According to one embodiment, the controller 251 may include a memory for storing input and/or output data and/or instructions. The memory may be included in the controller 251 in the form of a system-on-chip (SoC) or may be disposed on a printed circuit board (PCB) of the second optical transceiver 250 together with the controller 251 . The memory may include, for example, volatile memory such as random-access memory (RAM) and/or non-volatile memory such as read-only memory (ROM). The volatile memory may include, for example, at least one of Dynamic RAM (DRAM), Static RAM (SRAM), Cache RAM, and Pseudo SRAM (PSRAM). The nonvolatile memory may include, for example, at least one of a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a flash memory, a hard disk, a compact disk, and an embedded multi media card (eMMC). can

According to an embodiment, the light intensity detection module 253 may detect (or identify) the intensity of an optical signal received through the light receiving element module 270 . The light intensity detection module 253 may include, for example, a photodiode (PD) to output an electrical signal corresponding to the intensity of the light signal. The light intensity detection module 253 may output an electrical signal corresponding to the intensity of the light signal to the controller 210 . According to one embodiment, the light intensity detection module 253 may be included in the controller 251 when implemented in hardware.

According to an embodiment, the light transmitting device module 260 may output an optical signal based on a control signal of the controller 210 . The light transmitting element module 260 may include a laser diode (LD) for generating an optical signal. The laser diode may include, for example, a fabric perot LD (FP-LD), a distributed feedback LD (DFB-LD), a distributed bragg reflector LD (DBR-LD), an external cavity laser (ECL), and/or a vertical cavity laser (VCSEL). surface emitting laser). According to an embodiment, the laser diode may include a tunable LD in which a wavelength of an output optical signal is adjusted based on voltage, current, and/or temperature. According to an embodiment, the control signal transmitted from the controller 251 may be amplified by the first amplifier 271 and then provided to the light transmitting element module 260 .

According to an embodiment, the light receiving element module 270 may receive an optical signal provided from an optical network. The light receiving element module 270 may output an electrical signal corresponding to the received optical signal. An electrical signal output from the light receiving element module 270 may be amplified by the second amplifier 273 and then provided to the controller 251 and the connector 280 . According to an embodiment, the light receiving element module 270 may include a photodiode (PD) to output an electrical signal corresponding to the optical signal. The photodiode may include, for example, a P-I-N PD (PIN-PD) and an avalanche PD (APD).

According to an embodiment, the connector 280 is an electrical interface (eg, the electrical interface 155 of FIG. 1 ), and the second optical transceiver 250 and another electronic device (eg, the second electronic device 150 of FIG. 1 ). )) can support electrical coupling between them.

According to an embodiment, the controller 251 may detect (or identify) the intensity of the optical signal when the optical signal is received by the light receiving element module 270 . For example, when the first optical signal of the first wavelength is received from the first optical transceiver 200 through the light receiving element module 270, the controller 251 transmits the first optical signal through the light intensity detection module 253. The strength of the signal can be identified. For another example, when the second optical signal of the second wavelength is received from the first optical transceiver 200 through the light receiving element module 270, the controller 251 transmits the second optical signal through the light intensity detection module 253. The intensity of the light signal can be identified. For another example, when the third optical signal of the third wavelength is received from the first optical transceiver 200 through the light receiving element module 270, the controller 251 transmits the optical signal through the light intensity detection module 253. 3 The strength of the light signal can be identified.

According to an embodiment, the controller 251 may transmit information indicating the strength of an optical signal to the first optical transceiver 200 through the optical transmission element module 260 . For example, the controller 251, in response to receiving the first optical signal (or the second optical signal or the third optical signal) from the first optical transceiver 200, the first optical signal (or the second optical signal) After generating information indicating the strength of an optical signal or a third optical signal, modulating communication data with a subcarrier different from the modulating carrier wave (or a subcarrier of low frequency), the optical signal obtained by synthesizing the carrier wave and the subcarrier is optically transmitted. It can be transmitted to the first optical transceiver 200 through the device module 260 . In this case, the controller 251 may use a frequency shift keying (FSK) modulation scheme. However, the modulation method performed by the controller 251 is not limited to the FSK method, and other modulation methods may be used.

As described above, the second optical transceiver 250 may provide feedback information to the first optical transceiver 200 so that the intensity of the optical signal of the first optical transceiver 200 has the greatest value. Accordingly, the first optical transceiver 200 can adjust and fix the wavelength of the optical signal without separate hardware for monitoring the wavelength of the optical signal.

3 is a flowchart illustrating an example of a method of adjusting a wavelength in a first optical transceiver according to an embodiment. 4A and 4B are graphs for explaining an example of a method of adjusting a wavelength in a first optical transceiver according to an exemplary embodiment.

3 to 4B, in operation 301, a first optical transceiver (the first optical transceiver 101-1, ..., or 101-k of FIG. 1 or the first optical transceiver 200 of FIG. 2A) ) may receive information indicating the strength of a plurality of optical signals corresponding to different wavelengths. For example, the first optical transceiver 200 transmits the first optical signal of the first wavelength to the second optical transceiver (eg, the second optical transceiver of FIG. 1 ((101-k+1), ... , or ( 101-2k) or the second optical transceiver 250 of FIG. 2B), and information indicating the strength of the first optical signal may be received from the second optical transceiver. After transmitting the first optical signal, the first optical transceiver 200 transmits a second optical signal of a second wavelength to the second optical transceiver 250, and transmits the second optical signal from the second optical transceiver 250. Information indicating the strength of may be received. After transmitting the second optical signal, the first optical transceiver 200 transmits a third optical signal of a third wavelength to the second optical transceiver 250, and transmits the third optical signal from the second optical transceiver 250. Information indicating strength may be received. For another example, the first optical transceiver 200 sequentially transmits a first optical signal of a first wavelength, a second optical signal of a second wavelength, and a third optical signal of a third wavelength to the second optical transceiver 250 and receive information indicating the intensity of the first optical signal, information indicating the intensity of the second optical signal, and information indicating the intensity of the third optical signal from the second optical transceiver 250. . Here, the first wavelength, the second wavelength, and the third wavelength may have different values. According to an exemplary embodiment, the first optical transceiver 200 acquires a subcarrier signal from the optical signal received from the second optical transceiver 250 using a filter, and demodulates the acquired subcarrier signal, thereby increasing the intensity of the optical signal. It is possible to obtain information indicating.

In operation 303, the first optical transceiver 200 may identify an intensity change amount of an optical signal based on the received information. For example, as shown in FIG. 4A , the first optical transceiver 200 transmits information indicating the intensity p1 of the first optical signal of the first wavelength w1 and the second optical signal of the second wavelength w2. Based on the information indicating the intensity pl2, a difference between the intensity pl1 of the first optical signal and the intensity pl2 of the second optical signal is identified, and the intensity of the second optical signal of the second wavelength w2 The intensity (pl2) of the second optical signal and the intensity (pl3) of the third optical signal based on the information indicating (pl2) and the information indicating the intensity (pl3) of the third optical signal of the third wavelength (w3) By identifying the difference between the two, it is possible to identify the amount of change in the intensity of the optical signal.

In operation 305, the first optical transceiver 200 may identify a wavelength that satisfies a specified condition based on the amount of change in intensity of the optical signal. The first optical transceiver 200 satisfies a condition for designating a wavelength corresponding to the point where the intensity of the optical signal becomes flat (or the first point where the intensity of the optical signal has the maximum value) by continuously monitoring the amount of change in the intensity of the optical signal. It can be determined by the wavelength of For example, as shown in FIG. 4A , the first optical transceiver 200 generates an intensity change (or slope) (a1) between an optical signal of the k−1 th wavelength (wk−1) and an optical signal of the k th wavelength (wk). is greater than or equal to the reference change amount (or reference slope), and the intensity change amount (or slope a2) of the optical signal of the kth wavelength (wk) and the optical signal of the k+1th wavelength (wk+1) is the reference change amount (or reference slope). ), the kth wavelength (wk) may be determined as a wavelength that satisfies a specified condition.

In operation 307, the first optical transceiver 200 may adjust a wavelength of an optical signal output through the first optical transceiver 200 based on the identified wavelength. For example, the first optical transceiver 200 acquires a fourth wavelength by applying a specified value to a wavelength that satisfies a specified condition, and sets the wavelength of an optical signal output from the first optical transceiver 200 to the fourth wavelength. can be adjusted to According to an embodiment, the first optical transceiver 200 may determine a specified value for acquiring the fourth wavelength based on a wavelength that satisfies a specified condition. For example, as shown in the graph 410 of FIG. 4B , when the k-th wavelength (wk) shorter than the center wavelength is determined as a wavelength that satisfies a designated condition, the first optical transceiver 200 ) to a wavelength (wk+α) obtained by applying the first value α to the k-th wavelength wk (or longer than the k-th wavelength wk by the first value α) can be adjusted For another example, as shown in the graph 420 of FIG. 4B, when the n-th wavelength wn, which is longer than the center wavelength, is determined to be a wavelength that satisfies a specified condition, the first optical transceiver 200 is the first optical transceiver ( 200), the wavelength (wn−β) obtained by applying the second value β to the nth wavelength wn (or shorter than the nth wavelength wn by the second value β) can be adjusted to According to an embodiment, while the first optical transceiver 200 transmits an optical signal to the second optical transceiver 250, information (or feedback) indicating the strength of the optical signal received from the second optical transceiver 250 An operation of adjusting the wavelength of the optical signal transmitted to the second optical transceiver 200 based on information) may be continuously performed.

As described above, the first optical transceiver 200 may adjust the wavelength of an optical signal based on feedback information (eg, information indicating intensities of a plurality of optical signals) of the second optical transceiver 250 . Since the first optical transceiver 200 adjusts and fixes the wavelength of the optical signal without separate hardware for monitoring the wavelength of the optical signal, compared to optical transceivers using separate hardware for monitoring the wavelength of the optical signal, the first optical transceiver 200 is smaller than the optical transceiver. It has volume and can lower production cost by saving hardware cost.

5 is a flowchart illustrating another example of a method of adjusting a wavelength in a first optical transceiver according to an exemplary embodiment. 6 is a graph for explaining another example of a method of adjusting a wavelength in a first optical transceiver according to an embodiment.

5 and 6, in operation 501, a first optical transceiver (the first optical transceiver 101-1, ..., or 101-k of FIG. 1 or the first optical transceiver 200 of FIG. 2A) ) may receive information indicating the strength of a plurality of optical signals corresponding to different wavelengths. For example, the first optical transceiver 200 transmits the first optical signal of the first wavelength to the second optical transceiver (eg, the second optical transceiver of FIG. 1 ((101-k+1), ... , or ( 101-2k) or the second optical transceiver 250 of FIG. 2B), and information indicating the strength of the first optical signal may be received from the second optical transceiver. After transmitting the first optical signal, the first optical transceiver 200 transmits a second optical signal of a second wavelength to the second optical transceiver 250, and transmits the second optical signal from the second optical transceiver 250. Information indicating the strength of may be received. After transmitting the second optical signal, the first optical transceiver 200 transmits a third optical signal of a third wavelength to the second optical transceiver 250, and transmits the third optical signal from the second optical transceiver 250. Information indicating strength may be received. For another example, the first optical transceiver 200 sequentially transmits a first optical signal of a first wavelength, a second optical signal of a second wavelength, and a third optical signal of a third wavelength to the second optical transceiver 250 and receive information indicating the intensity of the first optical signal, information indicating the intensity of the second optical signal, and information indicating the intensity of the third optical signal from the second optical transceiver 250. . Here, the first wavelength, the second wavelength, and the third wavelength may have different values. According to an exemplary embodiment, the first optical transceiver 200 acquires a subcarrier signal from the optical signal received from the second optical transceiver 250 using a filter, and demodulates the acquired subcarrier signal, thereby increasing the intensity of the optical signal. It is possible to obtain information indicating.

In operation 503, the first optical transceiver 200 may generate reference data based on information indicating intensities of a plurality of optical signals. For example, the controller 210 uses interpolation to obtain information indicating the intensity of the optical signal (eg, the graph 610 of FIG. By generating the graph 620), reference data may be generated. For another example, the first optical transceiver 200 loads information on the intensity of optical signals according to previously stored wavelengths, and information indicating the intensity of a plurality of optical signals (eg, the graph 610 of FIG. 6 ). ), it is possible to obtain reference data by correcting the information loaded from the memory.

In operation 505, the first optical transceiver 200 may adjust the wavelength of the optical signal based on the reference data. For example, in the first optical transceiver 200, the wavelength of an optical signal output from the first optical transceiver 200 is a wavelength range wi in which the intensity of the optical signal is maximum, as shown in the graph 620 of FIG. The wavelength of the optical signal output from the first optical transceiver 200 may be adjusted so as to be included in the .

As described above, the first optical transceiver 200 continuously controls the intensity of the optical signal output through the first optical transceiver 200 based on information (or feedback information) provided from the second optical transceiver 250. , and based on the monitoring result, the wavelength of the optical signal output through the first optical transceiver 200 may be adjusted in real time. Since the first optical transceiver 200 adjusts and fixes the wavelength of the optical signal without separate hardware for monitoring the wavelength of the optical signal, compared to optical transceivers using separate hardware for monitoring the wavelength of the optical signal, the first optical transceiver 200 is smaller than the optical transceiver. It has volume and can lower production cost by saving hardware cost.

7 is a flowchart illustrating a method of generating feedback information in a second optical transceiver according to an exemplary embodiment.

Referring to FIG. 7 , in operation 701, a second optical transceiver (eg, the second optical transceiver 101-k+1, ..., 101-2k of FIG. 1 or the second optical transceiver 250 of FIG. 2B) ) may receive an optical signal. For example, the second optical transceiver 250 may be a first optical transceiver (eg, the first optical transceivers 101-1, ..., 101-k of FIG. 1 or the first optical transceiver 200 of FIG. 2A). ), a first optical signal of a first wavelength (or a second optical signal of a second wavelength, or a third optical signal of a third wavelength) may be received.

In operation 703, the second optical transceiver 250 may identify the strength of the received optical signal. For example, the second optical transceiver 250 may identify the intensity of the first optical signal of the first wavelength.

In operation 705, the second optical transceiver 250 may transmit information indicating the strength of an optical signal. For example, the second optical transceiver 250 generates information indicating the strength of the first optical signal, modulates the generated information into a subcarrier different from a carrier for modulating communication data (or a subcarrier of a low frequency), An optical signal obtained by synthesizing a carrier wave and a subcarrier may be transmitted to the first optical transceiver 200 .

In the above, it has been described that the second optical transceiver 250 identifies the intensity of an optical signal of a specific wavelength and transmits information indicating the intensity of the optical signal, but the second optical transceiver 250 according to an embodiment During a certain period of time, the intensity of a plurality of optical signals having different wavelengths may be identified, and information indicating the intensity of each of the plurality of optical signals may be transmitted to the first optical transceiver 200 .

As described above, the second optical transceiver 250 may generate feedback information for adjusting and/or fixing a wavelength of the first optical transceiver 200 and provide the generated feedback information to the first optical transceiver 200 .

The devices described above may be implemented as hardware components, software components, and/or a combination of hardware components and software components. For example, devices and components described in the embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA) , a programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions. A processing device may run an operating system (OS) and one or more software applications running on the operating system. A processing device may also access, store, manipulate, process, and generate data in response to execution of software. For convenience of understanding, there are cases in which one processing device is used, but those skilled in the art will understand that the processing device includes a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that it can include. For example, a processing device may include a plurality of processors or a processor and a controller. Other processing configurations are also possible, such as parallel processors.

Software may include a computer program, code, instructions, or a combination of one or more of the foregoing, which configures a processing device to operate as desired or processes independently or collectively. You can command the device. Software and/or data may be any tangible machine, component, physical device, virtual equipment, computer storage medium or device, intended to be interpreted by or provide instructions or data to a processing device. , or may be permanently or temporarily embodied in a transmitted signal wave. Software may be distributed on networked computer systems and stored or executed in a distributed manner. Software and data may be stored on one or more computer readable media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program commands recorded on the medium may be specially designed and configured for the embodiment or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. - includes hardware devices specially configured to store and execute program instructions, such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler.

The term "module" used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and is interchangeable with terms such as, for example, logic, logical blocks, parts, or circuits. can be used as A module may be an integrally constructed component or a minimal unit of components or a portion thereof that performs one or more functions.

As described above, although the embodiments have been described with limited examples and drawings, those skilled in the art can make various modifications and variations from the above description. For example, the described techniques may be performed in an order different from the method described, and/or components of the described system, structure, device, circuit, etc. may be combined or combined in a different form than the method described, or other components may be used. Or even if it is replaced or substituted by equivalents, appropriate results can be achieved.

Therefore, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims.

Claims (11)

In the first optical transceiver,
a transmitter optical sub-assembly (TOSA);
a receiver optical sub-assembly (ROSA);
wavelength tuning module; and
A controller operatively coupled to the light transmitting element module, the light receiving element module, and the wavelength adjustment module, the controller comprising:
Receiving information indicating intensities of a plurality of optical signals corresponding to different wavelengths through the light receiving element module;
Identifying an intensity variation of an optical signal based on the received information;
Identifying a wavelength that satisfies a specified condition based on the intensity variation of the identified optical signal, and
A first optical transceiver configured to adjust a wavelength of an optical signal transmitted from the optical transmission element module based on the identified wavelength.
According to claim 1,
The controller, as at least part of the operation of receiving information indicating the strength of the plurality of optical signals,
Obtaining a first subcarrier signal distinguished from a carrier signal including communication data from a first optical signal of a first wavelength received through the light receiving element module by using a filter;
demodulating the first subcarrier signal to obtain information indicating the strength of the first optical signal;
Obtaining a second sub-carrier signal that is distinguished from a carrier signal including communication data from a second optical signal of a second wavelength received through the light receiving element module by using the filter;
demodulating the second subcarrier signal to obtain information indicating the strength of the second optical signal;
Obtaining a third subcarrier signal that is distinguished from a carrier signal including communication data from a third optical signal of a third wavelength received through the light receiving element module by using the filter, and
The first optical transceiver configured to demodulate the third subcarrier signal to obtain information indicating the strength of the third optical signal.
According to claim 2,
The controller, as at least part of an operation of identifying a wavelength that satisfies the specified condition,
identifying an intensity variation between the first and second optical signals and an intensity variation between the second and third optical signals; and
A first optical transceiver configured to identify, in response to the identification, a wavelength that satisfies the specified condition.
According to claim 3,
The controller, as at least part of an operation of identifying a wavelength that satisfies the specified condition,
When the intensity change amounts of the first and second optical signals are greater than or equal to the reference change amount and the intensity change amounts of the second and third optical signals are less than the reference change amount, the second wavelength meets the specified condition A first optical transceiver configured to determine a wavelength that satisfies.
According to claim 4,
The controller, as at least part of the operation of adjusting the wavelength of the optical signal transmitted from the optical transmission element module,
By applying a preset value to the second wavelength, a long fourth wavelength is calculated, and
A first optical transceiver configured to adjust a wavelength of an optical signal transmitted from the optical transmission element module to the calculated fourth wavelength.
According to claim 1,
The light transmitting device module includes a tunable laser diode in which a wavelength of an optical signal is adjusted based on temperature, and
The wavelength control module includes a thermo-electric cooler (TEC) for adjusting the temperature of the optical transmission element module.
In the first optical transceiver,
a transmitter optical sub-assembly (TOSA);
a receiver optical sub-assembly (ROSA);
wavelength tuning module; and
A controller operatively coupled to the light transmitting element module, the light receiving element module, and the wavelength adjustment module, the controller comprising:
Receiving information indicating intensities of a plurality of optical signals corresponding to different wavelengths through the light receiving element module;
generating reference data based on information indicating intensities of the plurality of optical signals; and
A first optical transceiver configured to adjust a wavelength of an optical signal transmitted through the optical transmission element module based on the reference data.
According to claim 7,
The controller, as at least part of the operation of receiving information indicating the strength of the plurality of optical signals,
Obtaining a first subcarrier signal distinguished from a carrier signal including communication data from a first optical signal of a first wavelength received through the light receiving element module by using a filter;
demodulating the first subcarrier signal to obtain information indicating the strength of the first optical signal;
Obtaining a second sub-carrier signal that is distinguished from a carrier signal including communication data from a second optical signal of a second wavelength received through the light receiving element module by using the filter;
demodulating the second subcarrier signal to obtain information indicating the strength of the second optical signal;
Obtaining a third subcarrier signal that is distinguished from a carrier signal including communication data from a third optical signal of a third wavelength received through the light receiving element module by using the filter, and
The first optical transceiver configured to demodulate the third subcarrier signal to obtain information indicating the strength of the third optical signal.
According to claim 7,
further comprising memory;
The controller, as at least part of the operation of generating the reference data,
The first optical transceiver configured to generate the reference data by correcting intensity information of optical signals according to wavelengths previously stored in the memory based on the information indicating the intensities of the plurality of optical signals.
According to claim 7,
The controller, as at least part of the operation of generating the reference data,
The first optical transceiver configured to generate the reference data by generating intensity information of optical signals according to wavelengths from information indicating the intensities of the plurality of optical signals using interpolation.
According to claim 7,
The controller, as at least part of the operation of adjusting the wavelength of the optical signal,
Based on the reference data, identifying a wavelength range in which the intensity of the optical signal is maximized, and
A first optical transceiver configured to adjust a wavelength of an optical signal output from the optical transmission element module through the wavelength adjustment module so that the wavelength of the optical signal transmitted through the optical transmission element module is included in the wavelength range.

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