CN113196692B - Optical transmission apparatus and method - Google Patents

Optical transmission apparatus and method Download PDF

Info

Publication number
CN113196692B
CN113196692B CN201880100373.2A CN201880100373A CN113196692B CN 113196692 B CN113196692 B CN 113196692B CN 201880100373 A CN201880100373 A CN 201880100373A CN 113196692 B CN113196692 B CN 113196692B
Authority
CN
China
Prior art keywords
modulator
light beam
optical
arm
driver
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201880100373.2A
Other languages
Chinese (zh)
Other versions
CN113196692A (en
Inventor
高磊
董振
锁靖
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huawei Technologies Co Ltd
Original Assignee
Huawei Technologies Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Publication of CN113196692A publication Critical patent/CN113196692A/en
Application granted granted Critical
Publication of CN113196692B publication Critical patent/CN113196692B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/516—Details of coding or modulation

Abstract

The application provides an optical transmitting device and method, and relates to the technical field of optical communication. In the present application, the 1/4 wave plate can convert linearly polarized light output by the laser into circularly polarized light. The circularly polarized light will remain circularly polarized when transmitted through the circularly maintaining fiber to the polarization adjusting modulator. The polarization adjustment modulator can divide the circularly polarized light into two light beams of TE polarization state and TM polarization state, and rotate the light beam of TM polarization state into TE polarization state. And then, modulating the two parts of light beams and sending out the modulated light signals. It can be seen that the optical transmission device in the present application does not need a polarization maintaining fiber to transmit the optical beam, but uses a round fiber to transmit the optical beam. The processing process of the round-protecting optical fiber is simpler, so that the cost is reduced. In addition, because the optical signal can be modulated by one polarization adjustment modulator and one driver, the optical transmitting device has simple structure and lower cost.

Description

Optical transmission apparatus and method
Technical Field
The present application relates to the field of optical communication technologies, and in particular, to an optical transmission apparatus and method.
Background
In some current optical communication scenarios, the laser and modulator are separate and connected by an optical fiber. After receiving the light beam sent by the laser through the optical fiber, the modulator modulates the light beam by using service data and sends out an optical signal obtained by modulation. The light beam emitted by the laser is linearly polarized light with a Transverse Electric (TE) polarization state.
Since the modulator usually works in the TE mode, that is, when the modulator modulates the light beam, it needs to ensure that the polarization state of the light beam is the TE polarization state. For this reason, polarization-maintaining optical fibers are currently used to connect the laser and the modulator, so that the TE polarization state of the light beam emitted by the laser can be kept unchanged during transmission through the polarization-maintaining optical fibers, thereby ensuring that the light beam reaching the modulator is still TE polarization state.
However, polarization maintaining optical fibers are expensive to manufacture due to the need to transmit light beams through them. Therefore, the cost of the optical transmission device is caused to be high. Especially if the optical transmitting apparatus includes a laser array, a polarization maintaining fiber array is correspondingly required to transmit the optical beam, in which case the cost is higher.
Disclosure of Invention
The application provides an optical transmitting device and method, which can be used for solving the problem of higher cost of the optical transmitting device under the condition that a laser and a modulator are separated in the related art. The technical scheme is as follows:
in a first aspect, there is provided an optical transmission apparatus, including: the device comprises a laser, a 1/4 wave plate, a circle-protecting optical fiber, a polarization adjustment modulator and a first driver; the 1/4 wave plate is located between an optical port of the laser and a first interface of the round-protecting optical fiber, a second interface of the round-protecting optical fiber is connected with an optical port of the polarization adjusting modulator, an electric port of the polarization adjusting modulator is connected with the first driver, and the 1/4 wave plate is used for adjusting linearly polarized light output by the laser into circularly polarized light.
The polarization state of the light beam can be kept unchanged in the transmission process by the round-protection fiber. When the included angle between the fast axis of the 1/4 wave plate and the polarization direction of the first light beam can be 45 degrees, the 1/4 wave plate can convert the first light beam in the linear polarization state into the second light beam in the circular polarization state. The circularly polarized light reaching the polarization adjustment modulator via the rounding fiber may be divided into two light portions, a TE polarization state and a Transverse Magnetic (TM) polarization state, and the TM polarization state light is rotated into the TE polarization state by the polarization adjustment modulator. Then, the two portions of light are modulated and transmitted. It can be seen that the present application does not require polarization maintaining optical fibers to transmit the light beams, but uses round maintaining optical fibers. The processing process of the round-protecting optical fiber is simpler, so that the cost is reduced.
Optionally, the polarization adjustment modulator comprises a polarization beam splitter PBS, a polarization rotator PR and a first modulator. The first optical port of the PBS is connected with the second interface of the round-robin optical fiber, the second optical port of the PBS is connected with the first optical port of the PR, the third optical port of the PBS is connected with the optical port of the first arm of the first modulator, the second optical port of the PR is connected with the optical port of the second arm of the first modulator, and the electrical port of the first modulator is connected with the first driver.
Optionally, a first electrical port in the first driver is connected to an electrical port on a first arm of the first modulator, the first electrical port is configured to output one of the differential signals generated by the first driver, a second electrical port in the first driver is connected to an electrical port on a second arm of the first modulator, and the second electrical port is configured to output the other of the differential signals generated by the first driver. That is, in the embodiment of the present application, the two arms of the first modulator may be driven simultaneously by the first driver, so that the same service data is modulated onto the two optical beams.
Optionally, the electrical port of the first driver is connected to an electrical port on the first arm of the first modulator; or, the electrical port of the first driver is connected to the electrical port on the second arm of the first modulator. In this implementation, the first driver may drive either arm of the first modulator for modulation, while the light beam on the other arm may not carry traffic data.
Optionally, the apparatus further comprises a second driver, the polarization modifying modulator comprising a polarization beam splitter PBS, a polarization rotator PR, a first modulator and a second modulator. The first optical port of the PBS is connected with the second interface of the round-robin optical fiber, the second optical port of the PBS is connected with the first optical port of the PR, the third optical port of the PBS is connected with the optical port of the first modulator, the second optical port of the PR is connected with the optical port of the second modulator, the electrical port of the first modulator is connected with the first driver, and the electrical port of the second modulator is connected with the second driver.
In this implementation, the optical transmitting apparatus may include two drivers and two modulators. Two paths of service data are modulated into two paths of light beams by driving one modulator by two drivers respectively. Namely, a dual-channel optical transmission device is realized.
Optionally, the first modulator and the second modulator are any one of a mach-zehnder modulator MZM, an electro-absorption modulator, and a micro-ring modulator.
Optionally, the device further comprises a lens. The lens is located between the laser and the 1/4 wave plate, or the lens is located between the 1/4 wave plate and the first interface of the round-protecting optical fiber. By adding a lens, the dispersed light emitted by the laser or the 1/4 wave plate can be focused.
Optionally, the apparatus further comprises a first lens and a second lens. The first lens is located between the laser and the 1/4 wave plate, and the second lens is located between the 1/4 wave plate and the first interface of the round-protecting optical fiber.
Optionally, the laser is a distributed feedback DFB laser, a distributed bragg emission DBR laser, or a tunable laser.
In a second aspect, an optical transmission method is provided. The method comprises the following steps: the laser outputs a first light beam to the 1/4 wave plate, wherein the first light beam is linearly polarized light; the 1/4 wave plate adjusts the polarization state of the first light beam to obtain a second light beam, and outputs the second light beam to the circle-protecting optical fiber, wherein the second light beam is circularly polarized light; the round-keeping optical fiber transmits the second light beam to a polarization adjustment modulator; the polarization adjustment modulator divides the second light beam into a third light beam and a fourth light beam, rotates the polarization state of the fourth light beam by 90 degrees, and the first driver drives the polarization adjustment modulator to modulate the third light beam and/or the rotated fourth light beam and output a modulated optical signal, wherein the polarization state of the third light beam is a TE polarization state, and the polarization state of the fourth light beam is a TM polarization state.
In the embodiment of the application, the 1/4 wave plate can convert linearly polarized light output by the laser into circularly polarized light. The circularly polarized light is transmitted to a polarization adjustment modulator through a circle-protecting optical fiber, the circularly polarized light can be divided into two light beams of a TE polarization state and a TM polarization state through the polarization adjustment modulator, and the light beam of the TM polarization state is rotated into the TE polarization state. Then, the two parts of light beams are modulated and then transmitted, so that on one hand, when the optical signal is transmitted by the optical transmission method provided by the embodiment of the application, the light beam does not need to be transmitted by the polarization maintaining optical fiber, and the circular maintaining optical fiber is adopted. The processing process of the round-protecting optical fiber is simpler, so that the cost is reduced. On the other hand, since the optical transmission apparatus for transmitting an optical signal in the embodiment of the present application includes fewer components, the structure is simpler. Therefore, the cost is low.
Optionally, the polarization-adjusting modulator comprises a polarization beam splitter PBS, a polarization rotator PR and a first modulator. In this case, the implementation process that the polarization adjustment modulator splits the second light beam into a third light beam and a fourth light beam, rotates the polarization state of the fourth light beam by 90 degrees, and the first driver drives the polarization adjustment modulator to modulate the third light beam and the fourth light beam, and outputs the modulated light beam may be: the PBS splits the second beam into a third beam and a fourth beam and outputs the third beam to the first arm of the first modulator and the fourth beam to the PR; the PR rotates the polarization state of the fourth light beam by 90 degrees and outputs the rotated fourth light beam to a second arm of the first modulator; the first driver drives the first arm of the first modulator to modulate the third light beam and drives the second arm of the first modulator to modulate the rotated fourth light beam according to first service data to obtain a first optical signal and a second optical signal, and the first modulator combines the first optical signal and the second optical signal and outputs the combined optical signal.
Optionally, the implementation process of the first driver driving the first arm of the first modulator to modulate the third light beam and driving the second arm of the first modulator to modulate the rotated fourth light beam according to the first service data may be: the first driver generates differential signals according to first service data, outputs a first path of signals in the differential signals to a first arm of the first modulator, and outputs a second path of signals in the differential signals to a second arm of the first modulator; the first arm of the first modulator modulates the third light beam under the driving of the first path of signal, and the second arm of the first modulator modulates the rotated fourth light beam under the driving of the second path of signal.
In this implementation manner, the first driver may output a differential signal, and drive the two arms of the first modulator to modulate through two paths of signals of the differential signal, so as to obtain two paths of optical signals carrying the same service data.
Optionally, when the polarization adjustment modulator includes a polarization beam splitter PBS, a polarization rotator PR and a first modulator, the polarization adjustment modulator divides the second light beam into a third light beam and a fourth light beam, rotates the polarization state of the fourth light beam by 90 degrees, and the first driver drives the polarization adjustment modulator to modulate the third light beam or the fourth light beam and output the modulated light beam may also be implemented as follows: the PBS splits the second beam into a third beam and a fourth beam and outputs the third beam to the first arm of the first modulator and the fourth beam to the PR; the PR rotates the polarization state of the fourth light beam by 90 degrees and outputs the rotated fourth light beam to a second arm of the first modulator; the first driver generates a path of electric signal according to the first service data and sends the generated electric signal to a first arm or a second arm of the first modulator; when the first driver sends the electric signal to the first arm of the first modulator, the first arm of the first modulator modulates the third light beam under the driving of the electric signal to obtain a first light signal, and the first modulator combines the first light signal and the rotated fourth light beam and outputs the combined light signal; when the first driver sends the electric signal to the second arm of the first modulator, the second arm of the first modulator modulates the rotated fourth light beam under the driving of the electric signal to obtain a second light signal, and the first modulator combines the second light signal and the third light beam and outputs the combined light signal.
In this implementation manner, the first driver generates a path of electrical signal according to the first service data, and drives any arm in the first modulator through the path of electrical signal to perform signal modulation, so as to obtain a path of optical signal carrying the first service data.
Optionally, the apparatus further comprises a second driver, the polarization modifying modulator comprising a polarization beam splitter PBS, a polarization rotator PR, a first modulator and a second modulator. In this case, the implementation process that the polarization adjustment modulator splits the second light beam into a third light beam and a fourth light beam, rotates the polarization state of the fourth light beam by 90 degrees, and the first driver drives the polarization adjustment modulator to modulate the third light beam and the rotated fourth light beam, and output the modulated light beam may be: the PBS splits the second beam into a third beam and a fourth beam and outputs the third beam to the first modulator and the fourth beam to the PR; the PR rotates the polarization state of the fourth light beam by 90 degrees and outputs the rotated fourth light beam to the second modulator; the first driver drives the first modulator to modulate the third light beam according to first service data to obtain a first optical signal, the second driver drives the second modulator to modulate the rotated fourth light beam according to second service data to obtain a second optical signal, and the second service data are different from the first service data; the first modulator outputs the first optical signal, and the second modulator outputs the second optical signal.
In this implementation, the first driver and the second driver may each drive one modulator, thereby modulating two different service data onto two light beams.
Optionally, the apparatus further comprises a lens, the lens being located between the laser and the 1/4 wave plate. In this case, the implementation process of the laser outputting the first beam to the 1/4 wave plate may be: the laser outputting the first beam to the lens; the lens focuses the first light beam and transmits the focused first light beam to the 1/4 wave plate.
Optionally, the apparatus further comprises a lens, the lens being located between the 1/4 wave plate and the first interface of the rounding fiber. In this case, the process of outputting the second light beam to the round fiber may be: the 1/4 wave plate outputs the second light beam to the lens; the lens focuses the second light beam and transmits the focused second light beam to the round-keeping optical fiber.
The technical scheme provided by the application uses the 1/4 wave plate to convert linearly polarized light output by the laser into circularly polarized light, and transmits the circularly polarized light to the polarization adjustment modulator through the round-protecting optical fiber to realize beam splitting and modulation of TE and TM polarization states and then output. Therefore, the beneficial effects brought by the method at least comprise: the light beam is transmitted by the round-keeping optical fiber, so that the processing process is simpler, and the cost is reduced; in addition, the optical signal can be modulated by one polarization adjusting modulator and one driver, and the optical signal modulator is simple in structure and low in cost.
Drawings
Fig. 1 is a schematic structural view of an optical transmission apparatus provided in the related art;
fig. 2 is a schematic structural view of another optical transmission apparatus provided in the related art;
fig. 3 is a schematic structural diagram of a first optical transmission apparatus according to an embodiment of the present application;
fig. 4 is a schematic structural diagram of a second optical transmission apparatus according to an embodiment of the present application;
fig. 5 is a schematic structural diagram of a third optical transmission apparatus provided in an embodiment of the present application;
fig. 6 is a schematic structural diagram of a fourth optical transmission apparatus according to an embodiment of the present application;
fig. 7 is a schematic structural diagram of a fifth optical transmission apparatus according to an embodiment of the present application;
fig. 8 is a schematic structural diagram of a sixth optical transmission apparatus according to an embodiment of the present application;
fig. 9 is a flowchart of an optical transmission method according to an embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.
Fig. 1 shows an optical transmission apparatus 100 provided in the related art. As shown in fig. 1, the apparatus includes a laser 101, a modulator 102, a driver 103, and a polarization maintaining fiber 104. The laser 101 and the modulator 102 are connected by a polarization maintaining fiber 104, and the driver 103 is connected to the modulator 102.
It should be noted that modulator 102 operates in the linear polarization (TE or TM) mode. Most often in the TE mode. That is, when the modulator modulates the light beam, it is necessary to ensure that the polarization state of the light beam is the TE polarization state. The following analysis is performed by way of example, with modulator 102 operating in TE mode.
The laser 101 is used to emit a beam that is linearly polarized in the TE polarization state. The polarization maintaining fiber 104 can transmit the light beam emitted from the laser 101 to the modulator 102, and during the transmission, the polarization maintaining fiber 104 can keep the polarization state of the light beam unchanged, so that the polarization state of the light beam reaching the modulator can be ensured to be the TE polarization state.
In the optical transmission apparatus 100 described above, it is necessary to transmit the TE-polarized optical beam emitted from the laser 101 through the polarization maintaining fiber to ensure that the optical beam reaching the modulator 102 is still TE-polarized. However, polarization maintaining fibers are expensive to process. Therefore, the cost of the optical transmission device is also high. In addition, in the multi-channel mode, when the laser array is composed of a plurality of lasers 101, it is also necessary to use a polarization maintaining fiber array to transmit the light beam accordingly. Because the industry chain of the current polarization maintaining optical fiber array is immature, the angle of each optical fiber can be aligned only in a manual alignment mode, and therefore, the cost is higher.
Because of the high processing cost of polarization maintaining optical fibers, there are optical transmission devices that do not use polarization maintaining optical fibers, but use ordinary optical fibers. Fig. 2 shows an optical transmission apparatus 200 provided in the related art that uses a common optical fiber to connect a laser and a modulator. As shown in fig. 2, the apparatus 200 includes a laser 201, a common optical fiber 202, a Polarization Beam Splitter (PBS) 203, a first modulator 204, a second modulator 205, a first Polarization Rotator (PR) 206, a second PR207, a Polarization Beam Combiner (PBC) 208, a first driver 209, and a second driver 210.
Wherein the laser 201 is used to emit a beam of TE polarization. The ordinary optical fiber 202 may transmit the beam of TE polarization emitted by the laser 201 to the PBS203. In the process of transmitting the light beam, the polarization direction of the light beam cannot be controlled by the common optical fiber 202. Therefore, the polarization state of the light beam reaching the PBS203 is uncertain.
The PBS203 splits the received light beam to obtain a first light beam in the TE polarization state and a second light beam in the TM polarization state. It should be noted that the polarization state of the light beam received by the PBS203 is uncertain. Therefore, it is not certain whether the optical powers of the first and second split beams are equal. In this case, the first and second beams cannot be processed by both arms of one modulator. Therefore, the PBS203 can send the first light beam to the first modulator 204, and the first light beam is modulated by the first modulator 204 under the driving of the first driver 209, resulting in a first optical signal. Similarly, the adjusted second light beam is modulated by the second modulator 205 under the driving of the second driver 210, resulting in a second optical signal.
Since the resulting optical power of the first optical signal and the second optical signal is still uncertain. Therefore, the second modulator 205 is configured to transmit the second optical signal to the second PR207, adjust the second optical signal back to the TM polarization state, combine the TM polarization state with the PBC208, and transmit the combined TM polarization state, thereby implementing a single-channel optical transmission apparatus.
Therefore, in the above apparatus 200, when a common optical fiber is used to connect the separated laser and modulator, in order to ensure that the polarization state of the light beam is the TE polarization state during modulation, multiple devices such as PBS, PR, and PBC need to be additionally added, and two drivers need to drive the two modulators to complete modulation, which is relatively complex in structure and relatively high in cost.
In view of the above-described problems with the optical transmission apparatus 100 and the optical transmission apparatus 200 provided in the related art, embodiments of the present application provide an optical transmission apparatus. The optical transmission device provided in the embodiment of the present application can solve the problem of high cost caused by adopting the polarization maintaining fiber, and can also solve the problem of high cost caused by the complicated structure of the optical transmission device 200. Next, an optical transmission device provided in an embodiment of the present application will be described with reference to the drawings. It should be noted that the various optical transmission devices provided in the embodiments of the present application may also be referred to as optical transmission devices.
Fig. 3 is a diagram of an optical transmission apparatus 300 according to an embodiment of the present application. The apparatus 300 comprises: a laser 301, a 1/4 wave plate 302, a rounding fiber 303, a polarization adjustment modulator 304, and a first driver 305. The 1/4 wave plate 302 is located between the optical port of the laser 301 and the first interface of the round-robin fiber 303, the second interface of the round-robin fiber 303 is connected to the optical port of the polarization adjustment modulator 304, and the electrical port of the polarization adjustment modulator 304 is connected to the electrical port of the first driver 305.
Illustratively, the laser 301 may be a laser capable of outputting linearly polarized light. For example, the laser 301 may be a Distributed Feedback (DFB) laser, a Distributed Bragg Reflector (DBR) laser, a tunable laser, or the like, which is not specifically limited in this embodiment of the present application.
In particular, the laser 301 may include one output optical port. Through the optical port, the laser 301 may output a first beam, which is linearly polarized light.
The 1/4 wave plate 302 is located behind the laser 301, and the first beam output from the laser 301 may be incident perpendicularly to the 1/4 wave plate 302. Wherein, an angle between the fast axis of the 1/4 wave plate 302 and the polarization direction of the first light beam may be 45 degrees. Thus, the normally incident first light beam will be converted into a second light beam of circular polarization after passing through the 1/4 wave plate. It should be noted that, in the embodiment of the present application, the included angle between the fast axis of the 1/4 wave plate 302 and the polarization direction of the first light beam may also be other values, for example, may be 43 degrees, 44 degrees, 46 degrees, etc., in consideration of the device error. In this case, the second beam adjusted by the 1/4 wave plate 302 may be elliptically polarized light, compared to the 45 degree angle. Therefore, the optical powers of the two light beams after being split by the PBS are not completely equal, but the optical power difference between the two light beams is small, so that the device provided in the embodiment of the present application can still be used for realizing the optical power difference.
The round fiber 303 includes a first interface and a second interface. Wherein, the second light beam output from the 1/4 wave plate 302 can enter the rounding fiber 303 from the first interface and output through the second interface. It should be noted that the circular polarization state of the light beam can be kept unchanged by the circular fiber 303 during the transmission of the light beam. Thus, the second light beam in the circular polarization state output from the 1/4 wave plate 302 will still be in the circular polarization state after being transmitted through the round-robin fiber 303.
The polarization modifying modulator 304 includes an input optical port, an output optical port, and an input electrical port. The second light beam output from the rounding fiber 303 may be input to the polarization adjustment modulator 304 through the input port. The polarization adjusting modulator 304 may split the second light beam into a third light beam and a fourth light beam of equal power. Wherein the third light beam may be in a TE polarization state and the fourth light beam may be in a TM polarization state. Then, the polarization adjustment modulator 304 may rotate the polarization state of the fourth light beam by 90 degrees, thereby obtaining a TE polarization state of the fourth light beam, and receive the electrical signal output by the first driver 305 through the input electrical port. Then, the polarization adjustment modulator 304 modulates the third light beam and/or the rotated fourth light beam under the driving of the received electrical signal, and sends out the modulated optical signal.
In this embodiment, the 1/4 wave plate converts linearly polarized light output from the laser into circularly polarized light. The circularly polarized light will remain circularly polarized when transmitted through the circularity preserving fiber to the polarization adjusting modulator. The polarization adjustment modulator can divide the circularly polarized light into two parts of beams of TE polarization state and TM polarization state, and the beam of TM polarization state is rotated into the TE polarization state. And then, after the two parts of light beams are modulated, the modulated light signals can be sent out. Therefore, on one hand, the optical transmitting device provided by the embodiment of the application does not need the polarization maintaining optical fiber to transmit the light beam, but adopts the round maintaining optical fiber to transmit the light beam, and the processing process of the round maintaining optical fiber is simpler, so that the cost is reduced. On the other hand, the modulation of the optical signal can be achieved by one polarization adjustment modulator and one driver in the present application. The device has simple structure and low cost.
In the optical transmission apparatus described in the above embodiments, the polarization adjustment modulator may be a modulator chip integrated with PBS, PR, a modulator, and the like. Alternatively, in a possible implementation, the polarization adjustment modulator may also be implemented by the implementation of the polarization adjustment modulator in the optical transmission apparatus shown in fig. 4.
Fig. 4 is a schematic structural diagram of another optical transmission apparatus 400 provided in an embodiment of the present application. The apparatus 400 includes a laser 401, a 1/4 wave plate 402, a rounding fiber 403, a polarization adjusting modulator 404, and a first driver 405, wherein the polarization adjusting modulator 404 includes a PBS4041, a PR4042, and a first modulator 4043.
It should be noted that, with reference to the description in the foregoing embodiments, details regarding the implementation of the laser 401 and the 1/4 wave plate 402 are not repeated herein. In addition, in the present embodiment, the round fiber 4 outputs the second light beam to the PBS4041 through the second interface.
The PBS4041 includes a first optical port, a second optical port, and a third optical port. The first optical port of the PBS4041 is connected to the second interface of the round-robin fiber 403. Through the first optical port, the PBS4041 may receive the second light beam transmitted by the round fiber 403. Upon receiving the second light beam, PBS4041 may split the second light beam into two light beams, a third light beam and a fourth light beam, respectively, and output the fourth light beam through the second optical port and the third light beam through the third optical port. Note that the polarization directions of the third and fourth light beams are orthogonal. Illustratively, the third light beam may be in the TE polarization state and the fourth light beam may be in the TM polarization state. Alternatively, the third beam is a TM polarized beam and the fourth beam is a TE polarized beam.
PR4042 includes a first optical port and a second optical port. Wherein, when the fourth light beam is in the TM polarization state, the first optical port of the PR4042 may be connected with the second optical port of the PBS4041. Thus, the PR4042 may receive the fourth light beam output from the PBS4041 through the first optical port and rotate the polarization direction of the fourth light beam by 90 degrees. The rotated fourth light beam is then output through the second optical port of PR 4042. The first optical port of PR4042 may be connected to the third optical port of PBS4041 when the third light beam is in the TM polarization state. Thus, PR4042 may receive the third light beam output from PBS4041 through the first optical port and rotate the polarization direction of the third light beam by 90 degrees. The rotated third light beam is then output through a second optical port of PR 4042.
The first modulator 4043 includes a first arm and a second arm. When the third light beam is in a TE polarization state and the fourth light beam is in a TM polarization state, the optical port of the first arm is connected to the third optical port of the PBS4041, and the optical port of the second arm is connected to the second optical port of the PR 4042. Thus, the first arm can receive the third beam from the PBS4041 and the second arm can receive the rotated fourth beam from the PR 4042.
It should be noted that the first arm and the second arm of the first modulator 4043 each include an electrical port, and the first driver 405 may include one or two electrical ports. When the first actuator 405 includes one electrical port, the electrical port of the first actuator 405 may be connected to the electrical port of the first arm or the second arm. If the electrical port of the first driver 405 is connected to the electrical port of the first arm, after receiving the third light beam output by the PBS4041, the first arm may further receive an electrical signal output by the first driver 405 according to the service data, and modulate the third light beam under the driving of the electrical signal, so as to obtain a first optical signal. Then, the first modulator 4043 may combine the first optical signal and the rotated fourth optical beam and transmit the combined optical signal. If the electrical port of the first driver 405 is connected to the electrical port of the second arm, after receiving the rotated fourth light beam output by the PR4042, the second arm may further receive an electrical signal output by the first driver 405 according to the service data, and modulate the rotated fourth light beam under the driving of the electrical signal, so as to obtain a second optical signal. The first modulator 4043 may then combine the third light beam and the second light signal and transmit the combined light.
Alternatively, when the first actuator 405 includes two electrical ports, a first electrical port thereof may be connected to an electrical port of a first arm, and a second electrical port thereof may be connected to an electrical port of a second arm. In this case, after receiving the third light beam output by the PBS4041, the first arm may further receive one of the differential signals generated by the first driver 405 according to the traffic data, and modulate the third light beam driven by the one of the differential signals. Similarly, after receiving the rotated fourth light beam output by the PR4042, the second arm may further receive another signal in the differential signals generated by the first driver 405 according to the traffic data, and modulate the rotated fourth light beam under the driving of the other signal, so as to obtain a second light signal. Then, the first modulator 4043 may combine the modulated first optical signal and the modulated second optical signal and transmit the combined optical signal.
It should be noted that the implementation of the first modulator 4043 is described above when the third light beam is in the TE polarization state and the fourth light beam is in the TM polarization state. Alternatively, when the third beam is in the TM polarization state and the fourth beam is in the TE polarization state, the optical port of the first arm is connected to the second optical port of PR4042, and the optical port of the second arm is connected to the third optical port of PBS4041. Thus, the first arm can receive the rotated third beam output by PR4042 and the second arm can receive the fourth beam output by PBS4041.
Similarly, the first and second arms of the first modulator 4043 each include an electrical port thereon, and the first driver 405 may include one or two electrical ports. The implementation is similar to the previous description except that in this implementation the beam modulated on the first arm of the first modulator 4043 is the third beam after PR rotation, and the beam modulated on the second arm is the fourth beam directly output by the PBS4041.
In the above various implementations, the two signals of the differential signal output by the first driver 405 are generated according to the same traffic data. That is, the two arms of the first modulator 4043, driven by the first driver 405, may modulate the same service data onto the two paths of TE polarization state light beams, respectively, and combine the two paths of optical signals carrying the same service data and then send out the combined signal.
Optionally, in the embodiment of the present application, the apparatus 400 may further include a lens 406. As shown in FIG. 5, the lens 406 may be positioned between the laser 401 and the 1/4 waveplate 402. Thus, the first beam emitted by the laser 401 may be transmitted to the 1/4 waveplate 402 after being focused by the lens 406. Alternatively, the lens 406 may be located between the 1/4 wave plate 402 and the first interface of the rounded optical fiber 403 (not shown in FIG. 5). Thus, the second light beam emitted from the 1/4 wave plate 402 can be focused by the lens 406 and then transmitted to the round fiber 403.
Optionally, in one possible implementation, the apparatus may include two lenses, a first lens 406 and a second lens 407, respectively. As shown in FIG. 6, a first lens 406 may be located between the laser 401 and the 1/4 waveplate 402, and a second lens 407 may be located at a first interface of the 1/4 waveplate 402 and the round keeping fiber 403. Thus, the first light beam emitted from the laser 401 may be focused by the first lens 406 and transmitted to the 1/4 wave plate 402, and the second light beam emitted from the 1/4 wave plate 402 may be focused by the second lens 407 and transmitted to the round keeping fiber 403.
It should be noted that the optical transmitting apparatus shown in fig. 4-6 provides a single-channel optical signal output.
In the embodiment of the application, the 1/4 wave plate converts linearly polarized light output by the laser into circularly polarized light and transmits the circularly polarized light to the PBS through the rounding optical fiber. The PBS may split the circularly polarized light into two beams of TE and TM polarization, and transmit the TE polarization to one arm of the first modulator and the TM polarization to the PR. The PR may rotate the TM polarization beam to the TE polarization and transmit the adjusted beam to the other arm of the first modulator. The two arms of the first modulator can modulate the light beam in the TE polarization state under the driving of the first driver, and send out the modulated optical signal. Therefore, on one hand, the optical transmitting device provided by the embodiment of the application does not need the polarization maintaining optical fiber to transmit the light beam, but adopts the round maintaining optical fiber to transmit the light beam, and the processing process of the round maintaining optical fiber is simpler, so that the cost is reduced. On the other hand, in the application, the optical signal can be modulated by one PBS, one PR, one modulator and one driver, so that the optical transmitting device has a simple structure and low cost.
Fig. 7 is a schematic diagram of another optical transmission apparatus 700 according to an embodiment of the present disclosure. As shown in FIG. 7, the apparatus 700 may include a laser 701, a 1/4 wave plate 702, a round fiber 703, a polarization adjusting modulator 704, a first driver 705, and a second driver 706. The polarization adjustment modulator 704 includes a PBS7041, a PR7042, a first modulator 7043, and a second modulator 7044, among others. The difference from fig. 4 is that fig. 7 provides an optical transmission apparatus supporting a dual channel optical signal.
It should be noted that, the implementation of the laser 701, the 1/4 wave plate 702 and the rounding fiber 703 may refer to the related description of fig. 4, and will not be described herein again. In addition, the implementation manners of the PBS7041, the PR7042, the first modulator 7043, and the first driver 705 may also refer to the related descriptions in fig. 4, and are not described herein again. The service data generated by the first driver 705 for generating a differential signal or a single-ended electrical signal is referred to as first service data, and the optical signal modulated by the first modulator 7043 and carrying the first service data is referred to as a first optical signal.
The second modulator 7044 includes a first optical port, a second optical port, and an electrical port. Wherein an electrical port of the second modulator 7044 is connected to an electrical port of the second driver 706. When the third light beam is in the TE polarization state and the fourth light beam is in the TM polarization state, the first optical port of the second modulator 7044 is connected to the second optical port of the PR 7042. Thus, the second modulator 7044 may receive the rotated fourth light beam output by the PR7042 through the first optical port. After receiving the rotated fourth light beam, the second modulator 7044 may receive an electrical signal output by the second driver 706 according to the second service data, and modulate the rotated fourth light beam under the driving of the electrical signal output by the second driver 706, so as to obtain a second optical signal carrying the second service data. Then, the second modulator 7044 sends out the second optical signal carrying the second service data through the second optical port.
When the third light beam is in the TM polarization state and the fourth light beam is in the TE polarization state, the first optical port of the second modulator 7044 is connected to the second optical port of the PBS 7041. Thus, through the first optical port, the second modulator 7044 can receive the fourth light beam output by the PBS 7041. After receiving the fourth light beam, the implementation manner of the second modulator 7044 modulating the fourth light beam may refer to the related description above, and will not be described herein again.
The first service data and the second service data in the above embodiment refer to two different service data. That is, in the embodiment of the present application, the two drivers may drive the two modulators to modulate the light beams respectively according to the two service data, so as to obtain two optical signals carrying different service data. In addition, in the embodiment of the present application, the first modulator 7043 and the second modulator 7044 may be any one of a mach-zehnder modulator (MZM), an electro-absorption modulator, and a micro-ring modulator. Alternatively, the first modulator and the second modulator may be other types of modulators. The embodiment of the present application does not limit this.
Optionally, the apparatus 700 may also include one or two lenses. When the apparatus 700 includes a lens, reference may be made to the implementation of the lens 406 included in the apparatus 400 in the foregoing embodiment. When the apparatus 700 includes two lenses, reference may be made to the implementation manner of the apparatus 400 in the foregoing embodiment when the apparatus includes the first lens 406 and the second lens 407, and the description of the embodiment of the present application is omitted here.
It should be noted that, in the optical transmission apparatus 200 (see fig. 2) provided in the foregoing related art, the first modulator and the second modulator are also driven by two drivers, respectively. However, since the optical power of the optical beams input to the two modulators in the optical transmission apparatus 200 is different and may be constantly changing, both drivers can only generate electrical signals to drive the connected modulators according to the same traffic data. In other words, in the related art, two drivers can drive only two modulators to modulate the same traffic data onto two optical beams.
In the embodiment of the present application, the PBS may split the second light beam in the circular polarization state transmitted by the round-keeping fiber into two light beams with equal power and orthogonal polarization states. Thus, the power of the two partial beams arriving at the modulator is also equal. Since the optical power of the light beams received by the two modulators is the same. Therefore, the two modulators can modulate the TE polarization state light beam according to different service data under the driving of the respective connected drivers, so as to obtain and send two optical signals carrying different service data. That is, in the embodiment of the present application, the power of the light source is equally divided into two parts, and each part is modulated by an independent modulator. It can be seen that the optical transmitter 200 provided in fig. 2 is a single optical transmitter (single channel optical transmitter), while the optical transmitter provided in the embodiments of the present application is two optical transmitters (dual channel transmitter).
It should be noted that, in the above embodiment, two drivers may drive two modulators to modulate two service data onto two optical signals for transmission. Alternatively, when the optical power of the second optical beam is large, on the basis of the optical transmission apparatus shown in fig. 7, a 1-to-2 optical beam splitter may be added to the branch between the PBS7041 and the first modulator 7043 to split the third optical beam into two beams, and a 1-to-2 optical beam splitter may be added after PR to split the rotated fourth optical beam into two beams, where 4 beams generated after splitting may be respectively input to 4 modulators, and the 4 modulators are driven by 4 drivers to respectively modulate the 4 beams, so as to output 4 optical signals. It should be noted that, only 4 optical signals are output as an example for description. If 5 optical signals are to be output, one of the two 1-to-2 optical splitters may be replaced with a 1-to-3 optical splitter. If 6 optical signals are to be output, the two 1-in-2 optical beam splitters can be replaced by two 1-in-3 optical beam splitters. If 8 optical signals are output, two 1-in-4 beam splitters may be used to replace the two 1-in-2 beam splitters, or 4 1-in-2 beam splitters may be directly added. That is, when an arbitrary optical signal is to be output, the implementation may be implemented by adding a corresponding optical splitter with reference to the above implementation manner, and details of the embodiment of the present application are not described herein again.
In addition, in the embodiment of the present application, after the second light beam is split into two light beams by the PBS, the two light beams may be modulated. A 90-degree phase shifter may be arranged behind one of the paths of modulated optical signals, and the optical signal passing through the 90-degree phase shifter and the other path of modulated optical signal are combined and output. In this case, the signal modulation scheme of the optical transmission device is an in-phase quadrature (IQ) modulation scheme, and modulation code patterns such as QPSK (quadrature phase shift keying) and QAM (quadrature amplitude modulation) can be generated.
Alternatively, if 4 beams are obtained by adding the beam splitter to split, two of the 4 beams can be arbitrarily selected. For convenience of description, two light beams are selected as the first light beam and the second light beam, and any two of the two light beams are the third light beam and the fourth light beam. And modulating the four light beams to correspondingly obtain a first light signal, a second light signal, a third light signal and a fourth light signal. And then, arranging a 90-degree phase shifter behind the first path of optical signal, and combining the first path of optical signal and the second path of optical signal which pass through the 90-degree phase shifter into an X-ray signal. And arranging a 90-degree phase shifter behind the third optical signal, combining the third optical signal and the fourth optical signal which pass through the 90-degree phase shifter into a Y optical signal, adding PR behind the Y optical signal, and combining and outputting the Y optical signal and the X optical signal which are polarized and rotated by 90 degrees after the PR through a Polarization Beam Combiner (PBC). In this case, the signal modulation scheme of the optical transmitter is a polarization-multiplexed in-phase quadrature (PM-IQ) modulation scheme or a polarization-multiplexed quadrature amplitude modulation (PM-QAM) scheme, and can generate code patterns such as PM-QPSK and PM-QAM.
Fig. 8 is a schematic diagram of another optical transmission apparatus 800 according to an embodiment of the present application. As shown in FIG. 8, the apparatus 800 includes a laser array 801, a 1/4 wave plate array 802, a rounded fiber array 803, a polarization adjusting modulator array 804, and a driver array 805.
The laser array 801 includes m lasers, the 1/4 wave plate array 802 includes m 1/4 wave plates, the rounding fiber array 803 includes m rounding fibers, the polarization adjustment modulator array 804 includes m polarization adjustment modulators, and the driver array includes m drivers or 2m drivers.
Specifically, m lasers, m 1/4 wave plates, m round-protecting fibers, and m polarization adjusting modulators are in one-to-one correspondence, and each polarization adjusting modulator corresponds to one or two drivers in the driver array. For specific implementation manners of each laser, the corresponding 1/4 wave plate, the corresponding rounding fiber, the corresponding polarization adjustment modulator, and the corresponding driver, reference may be made to the implementation manners of the laser, the 1/4 wave plate, the rounding fiber, the polarization adjustment modulator, and the driver introduced in any one of the optical transmission devices shown in fig. 4 to 7 in the foregoing embodiments, which is not described again in this embodiment of the present application.
In the embodiment of the present application, for some application scenarios, it may be necessary to arrange a laser array in the optical transmission apparatus and transmit multiple optical beams through the laser array. In this case, the optical transmitter may be provided with a 1/4 wave plate array, a rounding fiber array, a polarization adjustment modulator array, and a driver array. In this way, any laser in the laser array and the corresponding 1/4 wave plate, the rounding fiber, the polarization adjustment modulator, and the driver can be implemented with reference to the laser, the 1/4 wave plate, the rounding fiber, the polarization adjustment modulator, and the driver in the foregoing embodiments. Compared with the polarization maintaining fiber array in the related art, the circular-protection fiber array does not need to align the angles one by one like the polarization maintaining fiber array, the processing process is simple, and the cost is lower.
Next, an optical transmission method provided in an embodiment of the present application will be described. Fig. 9 is a flowchart of an optical transmission method according to an embodiment of the present application. As shown in fig. 9, the method includes the steps of:
step 901: the laser outputs a first light beam to the 1/4 wave plate, and the first light beam is linearly polarized light.
For the implementation of the laser to output the first light beam to the 1/4 wave plate, reference may be made to the related description of the laser in fig. 3 to 7, and details thereof are not repeated here.
Optionally, the beam of light output by the laser is divergent. Therefore, in a possible implementation manner, a lens can be arranged between the laser and the 1/4 wave plate, and the first light beam output by the laser can enter the 1/4 wave plate after being focused by the lens so as to reduce the loss of the optical power of the first light beam.
Step 902: the 1/4 wave plate adjusts the polarization state of the first light beam to obtain a second light beam, and outputs the second light beam to the circle-protecting optical fiber, wherein the second light beam is circularly polarized light.
The implementation process of this step can refer to the related description about the 1/4 wave plate in fig. 3-7, and will not be described herein again.
Step 903: the second light beam is transmitted to the polarization adjustment modulator by the round fiber.
The second light beam emitted from the 1/4 wave plate enters the round-protecting optical fiber and is transmitted to the polarization adjustment modulator through the round-protecting optical fiber. Because the polarization direction of the circularly polarized light beam can be kept unchanged by the rounding fiber, the second light beam reaching the polarization adjustment modulator will still be circularly polarized after being transmitted through the rounding fiber.
Optionally, a lens may be disposed between the 1/4 wave plate and the rounding fiber, and the second light beam output by the 1/4 wave plate may enter the rounding fiber for transmission after being focused by the lens.
Step 904: the polarization adjustment modulator divides the second light beam into a third light beam and a fourth light beam, rotates the polarization state of the fourth light beam by 90 degrees, and the first driver drives the polarization adjustment modulator to modulate the third light beam and/or the rotated fourth light beam and output a modulated optical signal.
The implementation of this step is different according to the implementation of the polarization adjustment modulator.
(1) The polarization-adjusting modulator comprises a PBS, a PR and a first modulator, i.e. this step is implemented by the polarization-adjusting modulator shown in fig. 4.
In this case, the PBS may receive the second light beam transmitted by the round-robin fiber and split the second light beam into two beams of two orthogonal polarization states. Wherein, the polarization state of one path of light beam is TE polarization state, and the polarization state of the other path of light beam is TM polarization state. In the embodiment of the present application, the TE polarization beam is taken as the third beam, and the TM polarization beam is taken as the fourth beam.
Since the second light beam received by the PBS is circularly polarized light, after separating the second light beam into the third light beam in the TE polarization state and the fourth light beam in the TM polarization state, the optical power of the third light beam and the fourth light beam will be equal. After splitting the second beam into the third and fourth beams, the PBS may output the third beam in the TE polarization state directly to the first arm of the first modulator because the first modulator operates in the TE mode. For the TM polarization fourth beam, the PBS may output the fourth beam to the PR for adjusting the TE polarization since the first modulator cannot directly modulate the fourth beam.
PR may rotate the polarization state of the fourth beam by 90 degrees after receiving the fourth beam. At this time, the rotated fourth light beam is also in the TE polarization state, so that the PR may output the rotated fourth light beam to the second arm of the first modulator.
The first modulator may perform signal modulation driven by the first driver after receiving the third light beam and the rotated fourth light beam. The first driver may be a single-ended output driver or a dual-output driver.
For example, if the first driver is a single-ended output driver and the first driver is connected to the first arm of the first modulator, the first driver may generate an electrical signal according to the first traffic data and send the electrical signal to the first arm of the first modulator. After the first arm of the first modulator receives the electric signal, the third light beam is modulated under the control of the electric signal, and a first optical signal is obtained. Since the electrical signal is generated according to the first traffic data, the first optical signal modulated under the control of the electrical signal will carry the first traffic data. And for the second arm of the first modulator, since it is not connected to the first driver, the second arm of the first modulator does not modulate the rotated fourth light beam. After the first arm of the first modulator modulates the third light beam, the first light signal carrying the first service data and the fourth light beam not carrying the service data may be combined and then transmitted.
It should be noted that if two optical signals with different powers and the same polarization state are combined and transmitted, a large power loss will be caused. However, the third light beam and the fourth light beam split by the PBS have equal optical power, and two optical signals with similar optical power and the same polarization state are directly transmitted after being combined into the beam, which does not cause large power loss. Therefore, after obtaining the first optical signal, the first modulator may not need to readjust the rotated fourth optical beam back to the TM polarization state, but may directly combine and transmit the first optical signal and the rotated fourth optical beam.
In addition, optionally, since the polarization state of the fourth light beam split by the PBS is adjusted by the PR, and the PR has a certain device loss, there is a certain difference between the optical power of the rotated fourth light beam and the optical power of the third light beam. In this case, the first and second arms of the first modulator are not balanced in power, and therefore, the extinction ratio of the first modulator is affected. Based on this, in the embodiment of the present application, in order to minimize the influence on the extinction ratio of the first modulator, the loss caused by PR may be controlled to be smaller than the first value, so as to ensure that the power imbalance between the first arm and the second arm of the first modulator is within a reasonable range, and further maintain the extinction ratio of the first modulator below the preset value. Wherein, the first value may be 0.2dB, and the predetermined value may be-20 dB.
Optionally, if the first driver is a single-ended output driver and the first driver is connected to the second arm of the first modulator, the first driver may generate an electrical signal according to the first service data and send the electrical signal to the second arm of the first modulator. After receiving the electrical signal, the second arm of the first modulator modulates the rotated fourth light beam under the control of the electrical signal, so as to obtain a second optical signal. Since the electrical signal is generated from the first traffic data, the second optical signal modulated under the control of the electrical signal will carry the first traffic data. And for the first arm of the first modulator, since it is not connected to the first driver, the first arm of the first modulator does not modulate the third beam. After the second optical signal obtained by modulating the second arm of the first modulator, the second optical signal carrying the first service data and the third optical beam not carrying the service data may be combined and then sent out.
As can be seen from the above description, when the first driver is a single-ended output driver, the first driver can drive only one of the two arms of the first modulator to modulate the first service data onto the corresponding light beam. Alternatively, the first driver may be a dual output driver, so that both arms of the first modulator may be driven simultaneously by the first driver for modulation.
Specifically, when the first driver has dual outputs, the first driver may generate a differential signal according to the first service data, where the differential signal includes two paths of signals. For convenience of description, two signals in the differential signal are respectively referred to as a first signal and a second signal. The first driver may send the first path of signals to a first arm of the first modulator and send the second path of signals to a second arm of the first modulator. After receiving the first path of signal, the first arm of the first modulator may modulate the third light beam under the control of the first path of signal, so as to obtain a first optical signal carrying the first service data. After receiving the second path of signal, the second arm of the first modulator may modulate the rotated fourth light beam under the control of the second path of signal, so as to obtain a second optical signal carrying the first service data. And then, the two paths of optical signals which are modulated by the first modulator, carry the first service data and have the same polarization state are combined and sent out.
(2) The polarization adjustment modulator includes PBS, PR, a first modulator, and a second modulator, and the optical transmission apparatus further includes a second driver therein, that is, this step is implemented by the polarization adjustment modulator shown in fig. 7.
The implementation processes of splitting the second light beam by the PBS, adjusting the polarization state of the fourth light beam by the PR, and modulating the first optical signal carrying the first service data by the first modulator under the driving of the first driver may refer to related descriptions in the first implementation manner, and are not described herein again.
Unlike the first implementation described above, the rotated fourth beam of the PR output will enter the second modulator. The second modulator may modulate the rotated fourth light beam under driving of the second driver after receiving the rotated fourth light beam. Specifically, the second driver may generate an electrical signal according to the second service data, and transmit the electrical signal to the second modulator, and the second modulator may modulate the second service data onto the rotated fourth light beam under the control of the electrical signal, so as to obtain a second optical signal carrying the second service data.
It should be noted that the first service data and the second service data are different. That is, in this implementation, two traffic data can be modulated onto two beams of light under the driving of two drivers, so that two optical signals carrying different traffic data can be obtained, and thus a dual-channel optical transmitter can be implemented.
It should be further noted that, in this implementation, a specific implementation manner in which the second driver drives the second modulator to modulate the rotated fourth light beam may refer to a related content in the first implementation manner in which the first driver drives the first modulator to modulate, and is not described herein again.
In the embodiment of the application, the 1/4 wave plate converts linearly polarized light output by the laser into circularly polarized light. The circularly polarized light will remain circularly polarized light by passing it through the circularly polarizing fiber to the polarization adjusting modulator. The circularly polarized light can be divided into two parts of beams with TE polarization state and TM polarization state by the polarization adjusting modulator, and the optical power of the two parts of beams is equal. On the basis, the two-part light beam can be modulated and transmitted by one modulator. Therefore, on one hand, when the optical signal is transmitted by the optical transmission method provided by the embodiment of the application, the light beam does not need to be transmitted by the polarization maintaining optical fiber, but the light beam is transmitted by the round maintaining optical fiber, and the processing process of the round maintaining optical fiber is simpler, so that the cost is reduced. On the other hand, since the optical transmission apparatus for transmitting an optical signal in the embodiment of the present application includes fewer components, the structure is simpler, and therefore, the cost is lower.
In addition, in this embodiment of the present application, the two modulators may modulate the light beam in the TE polarization state under the driving of the drivers connected to the two modulators, so as to obtain two optical signals carrying different service data, and send the two optical signals. That is, in the embodiment of the present application, the optical transmission apparatus can perform signal transmission by corresponding to two optical transmitters, whereas the optical transmission apparatus 200 provided in fig. 2 has a similar complexity structure and corresponds to only one optical transmitter.
The above-mentioned embodiments are provided not to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (18)

1. An optical transmission apparatus comprising a laser, a 1/4 wave plate, a rounding fiber, a polarization adjustment modulator comprising a polarization beam splitter PBS, a polarization rotator PR, and a first modulator, and a first driver;
the 1/4 wave plate is located between an optical port of the laser and a first interface of the round-protecting optical fiber, a second interface of the round-protecting optical fiber is connected with a first optical port of the PBS, a second optical port of the PBS is connected with a first optical port of the PR, a third optical port of the PBS is connected with an optical port of a first arm of the first modulator, a second optical port of the PR is connected with an optical port of a second arm of the first modulator, an electric port of the first modulator is connected with the first driver, and the 1/4 wave plate is used for adjusting linearly polarized light output by the laser into circularly polarized light.
2. The apparatus of claim 1, wherein a first electrical port in the first driver is coupled to an electrical port on a first arm of the first modulator, the first electrical port configured to output one of the differential signals generated by the first driver, a second electrical port in the first driver is coupled to an electrical port on a second arm of the first modulator, and the second electrical port configured to output the other of the differential signals generated by the first driver.
3. The apparatus of claim 1, wherein the electrical port of the first driver is connected to an electrical port on a first arm of the first modulator, or wherein the electrical port of the first driver is connected to an electrical port on a second arm of the first modulator.
4. The device of any of claims 1-3, wherein the device further comprises a lens;
the lens is located between the laser and the 1/4 wave plate, or the lens is located between the 1/4 wave plate and the first interface of the round-protecting optical fiber.
5. The apparatus of any of claims 1-3, wherein the apparatus further comprises a first lens and a second lens;
the first lens is located between the laser and the 1/4 wave plate, and the second lens is located between the 1/4 wave plate and the first interface of the round-protecting optical fiber.
6. An apparatus according to any of claims 1-3, wherein the laser is a distributed feedback DFB laser, a distributed Bragg emission DBR laser, or a tunable laser.
7. An optical transmission apparatus, characterized in that the apparatus comprises a laser, a 1/4 wave plate, a rounding fiber, a polarization adjustment modulator, a first driver and a second driver, the polarization adjustment modulator comprising a polarization beam splitter PBS, a polarization rotator PR, a first modulator and a second modulator;
the 1/4 wave plate is located between an optical port of the laser and a first interface of the round-protecting optical fiber, a first optical port of the PBS is connected with a second interface of the round-protecting optical fiber, a second optical port of the PBS is connected with a first optical port of the PR, a third optical port of the PBS is connected with an optical port of the first modulator, a second optical port of the PR is connected with an optical port of the second modulator, an electric port of the first modulator is connected with the first driver, an electric port of the second modulator is connected with the second driver, and the 1/4 wave plate is used for adjusting linearly polarized light output by the laser into circularly polarized light.
8. The apparatus of claim 7, wherein the first modulator and the second modulator are any one of a Mach-Zehnder modulator (MZM), an electro-absorption modulator, and a micro-ring modulator.
9. The apparatus of claim 7 or 8, wherein the apparatus further comprises a lens;
the lens is located between the laser and the 1/4 wave plate, or the lens is located between the 1/4 wave plate and the first interface of the round-protecting optical fiber.
10. The apparatus of claim 7 or 8, wherein the apparatus further comprises a first lens and a second lens;
the first lens is positioned between the laser and the 1/4 wave plate, and the second lens is positioned between the 1/4 wave plate and the first interface of the round-protecting optical fiber.
11. An apparatus according to claim 7 or 8, wherein the laser is a distributed feedback DFB laser, a distributed bragg emission DBR laser or a tunable laser.
12. An optical transmission method, characterized in that it is applied in the device of claim 1, said method comprising:
the laser outputs a first light beam to the 1/4 wave plate, and the first light beam is linearly polarized light;
the 1/4 wave plate adjusts the polarization state of the first light beam to obtain a second light beam, and outputs the second light beam to the circle-protecting optical fiber, wherein the second light beam is circularly polarized light;
the rounded optical fiber transmits the second light beam to the PBS in the polarization-adjusting modulator;
the PBS divides the second light beam into a third light beam and a fourth light beam, outputs the third light beam to a first arm of the first modulator, and outputs the fourth light beam to the PR, wherein the polarization state of the third light beam is Transverse Electric (TE) polarization state, and the polarization state of the fourth light beam is Transverse Magnetic (TM) polarization state;
the PR rotates the polarization state of the fourth light beam by 90 degrees and outputs the rotated fourth light beam to a second arm of the first modulator;
the first driver drives the first arm and/or the second arm of the first modulator to modulate the corresponding input light beams, combines the light beams output by the first arm and the second arm, and outputs the combined light signals.
13. The method of claim 12, wherein the first driver drives the first arm and/or the second arm of the first modulator to modulate the corresponding input optical beam and combine the optical beams output by the first arm and the second arm to output a combined optical signal, comprising:
the first driver drives the first arm of the first modulator to modulate the third light beam and drives the second arm of the first modulator to modulate the rotated fourth light beam according to first service data to obtain a first optical signal and a second optical signal, and the first modulator combines the first optical signal and the second optical signal and outputs the combined optical signal.
14. The method of claim 13, wherein the first driver drives the first arm of the first modulator to modulate the third beam and the second arm of the first modulator to modulate the rotated fourth beam according to the first traffic data, comprising:
the first driver generates differential signals according to first service data, outputs a first path of signals in the differential signals to a first arm of the first modulator, and outputs a second path of signals in the differential signals to a second arm of the first modulator;
the first arm of the first modulator modulates the third light beam under the driving of the first path of signal, and the second arm of the first modulator modulates the rotated fourth light beam under the driving of the second path of signal.
15. The method of claim 12, wherein the first driver drives the first arm and/or the second arm of the first modulator to modulate the corresponding input optical beam and combine the optical beams output by the first arm and the second arm to output a combined optical signal, comprising:
the first driver generates a path of electric signal according to the first service data and sends the generated electric signal to the first arm or the second arm of the first modulator;
when the first driver sends the electric signal to the first arm of the first modulator, the first arm of the first modulator modulates the third light beam under the driving of the electric signal to obtain a first light signal, and the first modulator combines the first light signal and the rotated fourth light beam and outputs the combined light signal;
when the first driver sends the electric signal to the second arm of the first modulator, the second arm of the first modulator modulates the rotated fourth light beam under the driving of the electric signal to obtain a second light signal, and the first modulator combines the second light signal and the third light beam and outputs the combined light signal.
16. An optical transmission method, characterized in that it is applied in the device of claim 7, said method comprising:
the laser outputs a first light beam to the 1/4 wave plate, and the first light beam is linearly polarized light;
the 1/4 wave plate adjusts the polarization state of the first light beam to obtain a second light beam, and outputs the second light beam to the circle-protecting optical fiber, wherein the second light beam is circularly polarized light;
the rounding fiber transmits the second light beam to the PBS in the polarization adjustment modulator;
the PBS splits the second beam into a third beam and a fourth beam and outputs the third beam to the first modulator and the fourth beam to the PR;
the PR rotates the polarization state of the fourth light beam by 90 degrees and outputs the rotated fourth light beam to the second modulator;
the first driver drives the first modulator to modulate the third light beam according to first service data to obtain a first optical signal, the second driver drives the second modulator to modulate the rotated fourth light beam according to second service data to obtain a second optical signal, and the second service data is different from the first service data;
the first modulator outputs the first optical signal, and the second modulator outputs the second optical signal.
17. The method of claim 16, wherein the apparatus further comprises a lens, the lens being located between the laser and the 1/4 wave plate;
the laser outputting a first beam to the 1/4 wave plate, comprising:
the laser outputting the first beam to the lens;
the lens focuses the first light beam and transmits the focused first light beam to the 1/4 wave plate.
18. The method of claim 16, wherein the apparatus further comprises a lens positioned between the 1/4 wave plate and the first interface of the rounding fiber;
the outputting the second light beam to the round fiber comprises:
the 1/4 wave plate outputs the second light beam to the lens;
the lens focuses the second light beam and transmits the focused second light beam to the round-keeping optical fiber.
CN201880100373.2A 2018-12-29 2018-12-29 Optical transmission apparatus and method Active CN113196692B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2018/125268 WO2020133325A1 (en) 2018-12-29 2018-12-29 Optical transmission device and method

Publications (2)

Publication Number Publication Date
CN113196692A CN113196692A (en) 2021-07-30
CN113196692B true CN113196692B (en) 2022-11-25

Family

ID=71125620

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201880100373.2A Active CN113196692B (en) 2018-12-29 2018-12-29 Optical transmission apparatus and method

Country Status (2)

Country Link
CN (1) CN113196692B (en)
WO (1) WO2020133325A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1406342A (en) * 1998-09-17 2003-03-26 康宁股份有限公司及密执安大学校务委员会 Circularly polarized fiber in optical circuits
CN103401610A (en) * 2013-08-06 2013-11-20 中国科学院长春光学精密机械与物理研究所 Differential-type circularly-polarized laser carrier communication system
CN104981992A (en) * 2013-12-30 2015-10-14 华为技术有限公司 Optical signal transmitter, receiver and method for modulation and demodulation
CN106063157A (en) * 2014-02-25 2016-10-26 日本电气株式会社 Optical transmitter and optical transmission method
CN106353898A (en) * 2016-10-25 2017-01-25 深圳大学 System for generating optical vortex
DE102016224615A1 (en) * 2016-12-09 2018-06-14 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Modulator arrangement and method for modulating light

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6003687B2 (en) * 2013-01-31 2016-10-05 富士通株式会社 Optical transmitter and modulated optical signal generation method
US9083462B2 (en) * 2013-02-25 2015-07-14 Loki Systems LLC Optical communications system
JP2016143018A (en) * 2015-02-05 2016-08-08 ソニー株式会社 Optical transmitter, optical receiver and optical fiber
US10222676B2 (en) * 2017-01-27 2019-03-05 Futurewei Technologies, Inc. Polarization insensitive integrated optical modulator

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1406342A (en) * 1998-09-17 2003-03-26 康宁股份有限公司及密执安大学校务委员会 Circularly polarized fiber in optical circuits
CN103401610A (en) * 2013-08-06 2013-11-20 中国科学院长春光学精密机械与物理研究所 Differential-type circularly-polarized laser carrier communication system
CN104981992A (en) * 2013-12-30 2015-10-14 华为技术有限公司 Optical signal transmitter, receiver and method for modulation and demodulation
CN106063157A (en) * 2014-02-25 2016-10-26 日本电气株式会社 Optical transmitter and optical transmission method
CN106353898A (en) * 2016-10-25 2017-01-25 深圳大学 System for generating optical vortex
DE102016224615A1 (en) * 2016-12-09 2018-06-14 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Modulator arrangement and method for modulating light

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
圆偏振调制激光通信系统设计;杨鹏等;《中国激光》;20120910(第09期);全文 *
基于空间光调制器的光束偏振态控制方法研究;翟中生等;《激光与光电子学进展》;20160310(第03期);全文 *

Also Published As

Publication number Publication date
CN113196692A (en) 2021-07-30
WO2020133325A1 (en) 2020-07-02

Similar Documents

Publication Publication Date Title
US8412047B2 (en) Polarization multiplexed light transmitter and control method thereof
US8676060B2 (en) Quadrature amplitude modulation signal generating device
US20040208646A1 (en) System and method for multi-level phase modulated communication
CN107819525B (en) Detection and compensation of power imbalance for transmitters
US11606148B2 (en) Polarization processing apparatus, optical transceiver, and optical polarization processing method
US9264142B2 (en) RZ optical modulator and RZ optical modulation method
US20140294402A1 (en) Optical transmission apparatus, optical transmission method and program for optical transmission
US11646800B2 (en) Optical transmitter and method for controller optical transmitter
US8737844B2 (en) Method and apparatus for implementing PDM-BPSK modulation and QPSK modulation in compatible manner
JPH05160492A (en) Improvement in rotatable joint for communication channel
US10788679B2 (en) Method and circuit for endless phase and polarization control
US8238758B2 (en) Three-arm DQPSK modulator
KR20130118957A (en) Optical transmission with polarization division multiplexing
CN113196692B (en) Optical transmission apparatus and method
WO2018214901A1 (en) Wavelength-division multiplexed polarization-insensitive transmissive modulator
WO2018061296A1 (en) Light modulator, and method for controlling light modulator
WO2012163008A1 (en) Signal modulation device and modulation method
JP2011166249A (en) Optical transmitter
WO2023174165A1 (en) Coherent receiving device, coherent transmitting device and coherent communication system
JP6109860B2 (en) Flexible optical modulator for advanced modulation formats featuring optical couplers with asymmetric power splitting
WO2022009324A1 (en) Optical transmitter
CN113141213B (en) Coherent transmitter, method for controlling coherent transmitter and coherent transceiving system
CN115694654A (en) Polarization encoding device, method and processor applied to quantum key distribution
JPH03148641A (en) Polarized light scrambler
JP2020108062A (en) Polarization multiplexed optical transmitter circuit and polarization multiplexed optical transceiver circuit

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant