KR101954136B1 - Synchronous optical receiver based-on silicon microring and wavelength-division multiplexer system using the same - Google Patents

Abstract

A silicon microring based synchronous optical receiver and a wavelength division multiplexing system using the same are disclosed. The synchronous optical receiver of the present invention includes N microring, receives an optical signal having N channels, resonates the wavelength of the received optical signal with a microring, converts the optical signal into N channels 1) -th data channel signal from the N-1 channel signals from the wavelength filter unit to N-1 data channels, and for amplifying the received N-1 data channel signals A clock channel unit for receiving the remaining one clock channel signal from the N channel signals from the channel unit and the wavelength filter unit and providing a retiming clock signal to each of the N-1 data channels, and a clock channel unit for providing N-1 data channels And a microring controller for controlling the resonance wavelength of the microring corresponding to each data channel.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon microring based synchronous optical receiver and a wavelength division multiplexing system using the same.

The present invention relates to an optical receiver, and more particularly, to a silicon microring-based synchronous optical receiver and a wavelength division multiplexing system using the same, which receive optical data in a sampling manner by constructing an optical link in a data sensor in a synchronous manner.

Recently, large-scale mega-data centers have been increasing in popularity as cloud computing, video streaming services, and Internet of Tings (IoT) technologies have been spotlighted, thereby increasing demands on transmission capacity in the data center. Major lines that were 10 gigabit-class have been upgraded to 40-gigabit class and are expected to upgrade to 100 gigabit class within the next three years.

In addition, as the data center becomes larger, wiring problems in the data center, which have not become big issues in the meantime, are also becoming an issue. Faced with increasing data capacity, there is a need to reduce the optical fiber. In addition, as the number of optical transceivers, which are major components, is increasing, manufacturers are being asked to improve their price competitiveness.

In the meantime, the Vertical-Cavity Surface Emitting Laser (VCSEL) technology has developed remarkably and occupies the market of the short-distance transmission field. However, the limit of the transmission distance and the increase of the optical line are encountered. In this respect, wavelength division multiplexing (WDM) technology has attracted a great deal of attention in light of the high bandwidth per optical fiber in optical communication technology for data sensors.

Conventional WDM technology has not been competitive due to expensive components compared to high performance and bandwidth efficiency when fabricated based on compound semiconductors. In particular, the system configuration was difficult due to the high price of a demultiplexer (wavelength demultiplexer).

Therefore, there is a need for an optical receiver capable of solving such a problem.

Korean Patent Laid-Open Publication No. 2016-0011752 (Feb.

SUMMARY OF THE INVENTION The present invention is directed to a silicon microring-based synchronous optical receiver and a wavelength division multiplexing system using the same, which transmit multiple wavelengths to one optical fiber and realize an optical receiver synchronously to reduce complexity and power consumption. have.

It is another object of the present invention to provide a silicon microring-based synchronous optical receiver and a wavelength division multiplexing system using the same, which can improve price competitiveness by using a silicon microring as a wavelength filter.

In order to achieve the above object, a silicon microring-based synchronous optical receiver according to the present invention includes N microring, receives an optical signal having N channels, 1) -th data channel signal of the N channel signals from the wavelength filter unit to N-1 pieces of data channels from the N-1 channel signals, the wavelength filter unit resonating the wavelength of the signal with the microring, A data channel unit for receiving the N-1 data channel signals and for amplifying the received N-1 data channel signals, and for receiving the remaining one clock channel signal from the N channel signals from the wavelength filter unit, A clock channel unit for providing a retiming clock signal to the channel, and a clock channel unit for providing a retiming clock signal for each of the N-1 data channels, The ring comprises a micro-controller for controlling.

The wavelength filter unit may include: an optical coupler formed laterally or vertically to receive the optical signal; an optical waveguide connected to the optical coupler and disposed adjacent to the microring; a photodetector for detecting the optical signal; And a heater arranged to be in contact with the ring to adjust an ambient temperature of the microring.

The data channel unit may include a first TIA (Transimpedance Amplifier) for amplifying the N-1 data channel signals to a signal processing size, and a second TIA for amplifying the first output signal amplified from the first TIA to the retiming clock signal And a retimer for retiming the signal.

The clock channel unit may further include a second TIA for amplifying the one clock channel signal and a second output signal amplified from the second TIA to the N-1 data channel as the retiming clock signal, And a distributor.

The microring controller may further include a peak detector for monitoring a peak value of the first output signal for each of the N-1 data channels, and a temperature detector for detecting a temperature of the microring using the peak value monitored from the peak detector. And a tuning FSM (Finite State Machine) for generating a value.

And the tuning FSM transmits the generated temperature tuning value to a heater disposed in contact with the microring.

The tuning FSM is characterized by generating a voltage value for the temperature at which the resonant wavelength minimally reacts with the ambient temperature as the temperature tuning value.

A wavelength division multiplexing system according to the present invention includes a laser unit for outputting an optical signal having multiple wavelengths, an optical transmitter for receiving the optical signal output from the laser unit and performing wavelength filtering and modulation of the received optical signal with a microring A synchronous optical receiver for receiving the optical signal modulated from the optical transmitter, wavelength-filtering the received optical signal by microring, performing a synchronous communication, and a synchronous optical receiver for receiving the optical signal between the laser unit and the optical transmitter, And an optical fiber unit disposed between the optical receivers for transmitting the optical signal, wherein the synchronous optical receiver includes N microrings, receives an optical signal having N channels, and adjusts a wavelength of the received optical signal to A wavelength filter unit resonating with the microring to perform wavelength filtering of the optical signal into N channel signals, A data channel unit for receiving N-1 data channel signals of the N channel signals from the wavelength filter unit and for amplifying the received N-1 data channel signals, A clock channel unit for receiving the remaining one clock channel signal from the N channel signals and providing a retiming clock signal to the N-1 data channels, and a clock channel unit for each of the N-1 data channels, And a microring controller for controlling the resonance wavelength of the microring corresponding to the microring.

The silicon microring-based synchronous optical receiver and wavelength division multiplexing system using the same according to the present invention can transmit multiple wavelengths to one optical fiber and realize an optical receiver synchronously, thereby reducing complexity and power consumption.

Synchronous optical receivers can also improve price competitiveness by using silicon micro rings as wavelength filters.

1 is a view for explaining a wavelength division multiplexing system according to the present invention.
2 is a view for explaining a synchronous optical receiver according to the present invention.
3 is a view for explaining a microring controller according to the present invention.
4 is a view for explaining the structure of a peak detector according to the present invention.

Wavelength division multiplexing asynchronous optical receivers that have been fabricated on the basis of conventional compound semiconductors have a problem in that the cost competitiveness is low due to expensive optical demultiplexer components and the size of the optical transceiver is increased because the degree of integration is not high. Accordingly, the present invention discloses a synchronous optical receiver capable of maximizing the wavelength division multiplexing scheme capable of transmitting multiple wavelengths through one optical fiber, and reducing the complexity and power consumption of the optical receiver.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals as used in the appended drawings denote like elements, unless indicated otherwise. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather obvious or understandable to those skilled in the art.

1 is a view for explaining a wavelength division multiplexing system according to the present invention.

1, the WDM system 50 includes a laser unit 10, an optical transmitter 20, a synchronous optical receiver 30, and an optical fiber unit 40.

The laser unit 10 uses a light source that outputs multiple wavelengths for wavelength division multiplexing. That is, the laser unit 10 outputs an optical signal having N channels. In this case, the laser unit 10 may use a quantum dot laser that outputs N wavelengths from one laser, or may output using N short wavelength lasers that output N wavelengths, respectively.

The optical transmitter 20 receives the optical signal output from the laser unit 10 and performs wavelength filtering and modulation on the received optical signal. At this time, the optical transmitter 20 performs wavelength filtering and modulation using a microring.

The synchronous optical receiver 30 receives the optical signal modulated from the optical transmitter 20 and wavelength-filters the received optical signal. The synchronous optical receiver 30 performs wavelength filtering using a microring having a very small chip area. This has the advantage that the synchronous optical receiver 30 can greatly reduce the chip area and the chip price. In addition, the synchronous optical receiver 30 synchronously configures optical links in the data center, which are conventionally constructed asynchronously, to receive optical data in a sampling manner. That is, the synchronous optical receiver 30 simultaneously receives N-1 data signals and one synchronized clock signal to compensate for a skew between data and a clock generated during transmission and reception, the current received from the photodetector can be converted into a voltage signal and amplified by a retiming method.

The optical fiber unit 40 includes a first optical fiber unit 41 and a second optical fiber unit 42, which are formed of optical fibers and transmit optical signals having multiple wavelengths. The first optical fiber unit 41 is disposed between the laser unit 10 and the optical transmitter 20 and transmits the optical signal output from the laser unit 10 to the optical transmitter 20. The second optical fiber unit 42 is disposed between the optical transmitter 20 and the synchronous optical receiver 30 and transmits the modulated optical signal output from the optical transmitter 20 to the synchronous optical receiver 30. In this case, the optical fiber unit 40 may use a single mode fiber (SMF) to secure a transmission distance.

2 is a view for explaining a synchronous optical receiver according to the present invention.

Referring to FIG. 2, the synchronous optical receiver 30 includes a wavelength filter unit 100, a data channel unit 200, a clock channel unit 300, and a microring control unit 400.

The wavelength filter unit 100 receives an optical signal having N channels. The wavelength filter unit 100 resonates the wavelength of the received optical signal with the microring 130 to divide the optical signal into N channels. The wavelength filter unit 100 includes an optical coupler 110, an optical waveguide 120, a microring 130, a photodetector 140, and a heater 150.

The optical coupler 110 is formed laterally or vertically to receive an optical signal. As the optical coupler 110, an edge coupler, a grating coupler, or the like may be used, and preferably, a highly productive lattice coupler may be used.

The optical waveguide 120 is connected to the optical coupler 110 and is disposed adjacent to the microring 130. The optical waveguide 120 can transmit the optical signal received from the optical coupler 110 to the microring 130 through coupling.

The microring 130 is coupled from the optical waveguide 120 and resonates the transmitted optical signal to filter the wavelength. At this time, the microring 130 includes N microrings to perform wavelength filtering on N channels. In detail, the microring 130 includes a first microring 131 and a second microring 132. The first microring 131 includes N-1 microrings, and wavelength-filters N-1 data channels out of N channels. The second microring 132 wavelength-filters the remaining one of the N channels. Here, the microring 130 can change the resonant wavelength according to the size of the ring, the width and depth of the optical waveguide constituting the ring. On the other hand, the microring 130 is formed in a chip-level size by a silicon-based semiconductor process. That is, the microring 130 can have a very small chip area.

The photodetector 140 detects the wavelength-filtered optical signal from the microring 130. The photodetector 140 includes a first photodetector 141 and a second photodetector 142. The first photodetector 141 is connected to the first microring 131 to detect N-1 data channel signals. The second photodetector 142 is connected to the second microring 132 to detect one clock channel signal. Here, the photodetector 140 is formed of a photodetector (PD), and a photodetector can mainly use a germanium photodetector (Germanium PD) to enhance detection efficiency.

The heater 150 is disposed in contact with the microring 130 and adjusts the temperature according to a temperature tuning value described later. Meanwhile, since the wavelength resonated by the microring 130 sensitively reacts to the ambient temperature, the temperature should be controlled, and the heater 150 performs this role. That is, the heater 150 adjusts the ambient temperature such that the resonant wavelength is maintained at a temperature at which the resonant wavelength is minimally reacted. The heater 150 includes a first heater 151 and a second heater 152. The first heater 151 is disposed in contact with the first microring 131 and the second heater 152 is disposed in contact with the first microring 131. [ 2 < / RTI >

The data channel unit 200 receives N-1 data channel signals among the N channel signals from the wavelength filter unit 100. At this time, the data channel unit 200 can receive N-1 data channel signals on N-1 data channels, respectively. The data channel unit 200 amplifies the received N-1 data channel signals. The data channel unit 200 includes a first TIA (Transimpedance Amplifier) 210 and a retimer 220.

The first TIA 210 is included in each of N-1 data channels. The first TIA 210 amplifies the N-1 data channel signals received from the wavelength filter unit 100 to a signal processing size.

The retimer 220 retiming the first output signal amplified from the first TIA 210 to a retiming clock signal, which will be described later. That is, the retimer 220 can receive the signal compensation through the signal adjustment of the output data channel signal.

The clock channel unit 300 receives one of the N channel signals from the wavelength filter unit 100. The clock channel unit 300 provides a retiming clock signal to N-1 data channels, respectively. The clock channel portion 300 includes a second TIA 310 and a clock channel divider 320.

The second TIA 310 amplifies one clock channel signal received from the wavelength filter unit 100 to a size capable of signal processing. The second TIA 310 may have the same structure as the first TIA 210. At this time, an amplifier may be additionally installed at the rear end of the second TIA 310. [

The clock channel distributor 320 provides the second output signal amplified from the second TIA 310 as a retiming clock signal for every N-1 data channels.

The microring controller 400 is included in every N-1 data channels to control the resonance wavelength of a microring corresponding to each data channel. Accordingly, the microring controller 400 can perform wavelength filtering of the optical signal into the N channel signals in the wavelength filter unit 100.

In addition, the microring controller 400 monitors the peak value of the first output signal for each of the N-1 data channels, and generates a temperature tuning value of the microring using the monitored peak value. At this time, the microring control unit 400 controls the generated temperature tuning value to be transmitted to the heater 150 connected to the corresponding data channel. Here, the temperature tuning value may be a voltage value for a temperature at which the resonant wavelength minimally reacts to the ambient temperature.

FIG. 3 is a view for explaining a microring controller according to the present invention, and FIG. 4 is a view for explaining a structure of a peak detector according to the present invention.

Referring to FIGS. 3 and 4, the microring controller 400 controls the temperature around the first microring ring 131 by the first heater 151. Accordingly, the microring control unit 400 enables the wavelength of the first microring 131 to resonate stably. The microring controller 400 includes a peak detector 410 and a tuning FSM (Finite State Machine) 420.

The peak detector 410 monitors the peak value of the first output signal amplified by the first TIA 210 for each of the N-1 data channels. The peak detector 410 can detect the peak value using the first output signal and the retiming clock signal.

Here, the peak value detected through the peak detector 410 may be compared with the reference voltage via the retimer 220, where the retimer 220 also uses a retiming clock signal. Meanwhile, the reference voltage may be a voltage that is transmitted from the reference DAC 230 and serves as a reference of the first output signal.

The tuning FSM 420 generates a temperature tuning value of the microring using the monitored peak value and the retiming clock signal from the peak detector 310. In particular, tuning FSM 420 may generate a temperature tuning value using the result of the comparison in re-timer 220. [ The tuning FSM 420 also transmits the generated temperature tuning value to the heater 150 arranged to contact the microring 130. At this time, the voltage value corresponding to the temperature tuning value may be transmitted to the heater 150 after passing through the DSM 240 and the server DAC 250.

As described above, the synchronous optical receiver 30 according to the present invention can transmit up to the clock channel without additional optical fiber by using the characteristic of the wavelength division multiplexing technique, thereby eliminating the burden on the additional hardware configuration and reducing power consumption . Further, by using a silicon microring having a small chip area as a wavelength filter, price competitiveness can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation in the embodiment in which said invention is directed. It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the appended claims.

10: laser section 20: optical transmitter
30: Synchronous optical receiver 40: Optical fiber unit
41: first optical fiber part 42: second optical fiber part
50: wavelength division multiplexing system 100: wavelength filter unit
110: optical coupler 120: optical waveguide
130: microring 131: first microring
132: second microring 140: photo detector
141: first photodetector 142: second photodetector
150: heater 151: first heater
152: second heater 200: data channel unit
210: First TIA 220: Retimer
230: Reference DAC 240: DSM
250: Thermal DAC 300: Clock channel part
310: second TIA 320: clock channel distributor
400: microring controller 410: peak detector
420: tuning FSM

Claims (8)

A method for wavelength-filtering (N-channel) optical signals by resonating a wavelength of the received optical signal with N microns, resonating the wavelength of the received optical signal with the microring, A wavelength filter unit;
A data channel unit for receiving N-1 data channel signals of the N channel signals from the wavelength filter unit, respectively, and for amplifying the received N-1 data channel signals;
A clock channel unit for receiving the remaining one clock channel signal of the N channel signals from the wavelength filter unit and providing a retiming clock signal to the N-1 data channels, respectively; And
And a microring controller included in each of the N-1 data channels to control a resonance wavelength of a microring corresponding to each data channel,
Wherein the data channel unit comprises:
A first TIA (Transimpedance Amplifier) for amplifying the N-1 data channel signals to a size capable of signal processing; And
And a retimer for retiming the first output signal amplified from the first TIA to the retiming clock signal,
Wherein the microring control unit comprises:
A peak detector for monitoring a peak value of the first output signal for each of the N-1 data channels, and detecting a peak value using the first output signal and the retiming clock signal; And
A tuning FSM (Finite State Machine) for generating a temperature tuning value of the microring using the monitored peak value from the peak detector;
And a plurality of micro-mirrors, each of the plurality of micro-mirrors including a plurality of micro-mirrors. The method according to claim 1,
The wavelength-
An optical coupler formed laterally or vertically for receiving the optical signal;
An optical waveguide connected to the optical coupler and disposed adjacent to the microring;
A photodetector for detecting the optical signal; And
A heater disposed in contact with the microring to control an ambient temperature of the microring;
Further comprising a plurality of micro-rings disposed on the silicon micro-ring. delete The method according to claim 1,
The clock channel unit includes:
A second TIA for amplifying the one clock channel signal; And
A clock channel divider for providing a second output signal amplified by the second TIA to the N-1 data channels as the retiming clock signal;
And a plurality of micro-mirrors, each of the plurality of micro-mirrors including a plurality of micro-mirrors. delete The method according to claim 1,
The tuning FSM,
And wherein the generated temperature tuning value is transmitted to a heater disposed in contact with the microring. The method according to claim 1,
The tuning FSM,
Wherein the temperature tuning value is a voltage value for a temperature at which the resonant wavelength minimally reacts to the ambient temperature. A laser unit for outputting an optical signal having multiple wavelengths;
An optical transmitter for receiving an optical signal output from the laser unit and performing wavelength filtering and modulation of the received optical signal with a microring;
A synchronous optical receiver for receiving the optical signal modulated from the optical transmitter, wavelength-filtering the received optical signal by microring, and performing synchronous communication; And
And an optical fiber unit disposed between the laser unit and the optical transmitter and between the optical transmitter and the synchronous optical receiver to transmit the optical signal,
The synchronous optical receiver includes:
A wavelength filter unit that includes N microrings, receives an optical signal having N channels, resonates a wavelength of the received optical signal with the microring, and wavelength-filters the optical signal into N channel signals;
A data channel unit for receiving N-1 data channel signals of the N channel signals from the wavelength filter unit, respectively, and for amplifying the received N-1 data channel signals;
A clock channel unit for receiving the remaining one clock channel signal of the N channel signals from the wavelength filter unit and providing a retiming clock signal to the N-1 data channels, respectively; And
And a microring controller included in each of the N-1 data channels to control a resonance wavelength of a microring corresponding to each data channel,
Wherein the data channel unit comprises:
A first TIA (Transimpedance Amplifier) for amplifying the N-1 data channel signals to a size capable of signal processing; And
And a retimer for retiming the first output signal amplified from the first TIA to the retiming clock signal,
Wherein the microring control unit comprises:
A peak detector for monitoring a peak value of the first output signal for each of the N-1 data channels, and detecting a peak value using the first output signal and the retiming clock signal; And
A tuning FSM (Finite State Machine) for generating a temperature tuning value of the microring using the monitored peak value from the peak detector;
And a wavelength division multiplexing system.

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