Method and apparatus for generating a dispersion compensation signal

• US 20100014872A1
• Filed: 09/22/2009
• Published: 01/21/2010
• Est. Priority Date: 03/30/2007
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Liu, Yue, Fu, Wei, Jia, Jia, Tao, Zhihui
• Granted Patent: US 8,244,141 B2
• Time in Patent Office: Days
• US Class Current: 398/158
• CPC Class Codes: H04B 10/25137 using pulse shaping at the transmitter, e.g. pre-chirping or dispersion supported transmission [DST]
• CPC Class Codes: H04B 10/5053 using a parallel, i.e. shunt, combination of modulators
• CPC Class Codes: H04B 10/5162 Return-to-zero modulation schemes
• CPC Class Codes: H04B 10/5165 Carrier suppressed; Single sideband; Double sideband or vestigial
• CPC Class Codes: H04B 2210/254 before the transmission line, i.e. pre-compensation

Abstract

An apparatus for generating a dispersion compensation signal includes a splitting module for splitting a data signal to be transmitted into N channels of data signals; N pre-processing modules for adjusting in frequency domain the phases and amplitudes of the N channels of data signals and outputting N channels of pre-warped electrical signals; an optical carrier generating module for generating N channels of coherent optical carriers; N electro-optic modulators for modulating the N channels of coherent optical carriers based on the N channels of pre-warped electrical signals and generating N channels of pre-warped optical signals; an optical coupling module for coupling the N channels of pre-warped optical signals into a dispersion compensation optical signal. By pre-processing the data signals, the present disclosure may allow the use of existing devices to generate a dispersion compensation signal so that the bandwidth requirement set by prior art on the electrical device is reduced.

Claims

1. An apparatus for generating a dispersion compensation signal, comprising a splitting module, N pre-processing modules, N electro-optic modulators, an optical carrier generating module and an optical coupling module, wherein

the splitting module is configured to split a data signal to be sent into N channels of data signals;

the N pre-processing modules are configured to adjust in frequency domain the phases and amplitudes of the N channels of data signals output from the splitting module and output N channels of pre-warped electrical signals;

the optical carrier generating module is configured to generate N channels of coherent optical carriers;

the N electro-optic modulators are configured to modulate the N channels of coherent optical carriers based on the N channels of pre-warped electrical signals and generate N channels of pre-warped optical signals; and

the optical coupling module is configured to couple the N channels of pre-warped optical signals into a dispersion compensation optical signal;

wherein N is a natural number greater than 1.

2. The apparatus of claim 1, wherein the pre-processing module comprises a digital pre-processing module and a digit-analog conversion module, wherein

the digital pre-processing module is configured to adjust in digital frequency domain the phases and amplitudes of the N channels of data signals and output N channels of digital pre-warped electrical signals;

and

the digit-analog conversion module is configured to convert the N channels of digital pre-warped electrical signals into N channels of analog pre-warped electrical signals.

3. The apparatus of claim 2, further comprising N optical delayers,

the N optical delayers are configured to delay the N channels of pre-warped optical signals generated by the electro-optic modulator and adjust the time difference among the N channels of pre-warped optical signals so that the adjusted N channels of pre-warped optical signals may enter the optical coupling module simultaneously.

4. The apparatus of claim 1, wherein the optical carrier generating module comprises at least one optical source for generating optical carriers, at least one clock signal generator and at least one electro-optic modulator and an optical splitter, wherein

the clock signal generator is configured to generate a clock signal having a frequency which is an integer multiple of half the data signal rate;

the electro-optic modulator is configured to modulate the optical carriers with the clock signal and obtain N channels of coherent optical carriers and combine the N channels of coherent optical carriers to output to the optical splitters; and

the optical splitter is configured to split the N channels of coherent optical carriers transmitted in combination into N channels of optical carriers which are transmitted separately.

5. The apparatus of claim 1, wherein the electro-optic modulator is a Mach-Zehnder modulator, or an Electro-Absorption modulator.

6. The apparatus of claim 2, wherein the electro-optic modulator is a Mach-Zehnder modulator, or an Electro-Absorption modulator.

7. The apparatus of claim 3, wherein the electro-optic modulator is a Mach-Zehnder modulator, or an Electro-Absorption modulator.

8. The apparatus of claim 4, wherein the electro-optic modulator is a Mach-Zehnder modulator, or an Electro-Absorption modulator.

9. A method for generating a dispersion compensation signal, comprising:

splitting a data signal to be transmitted into N channels of data signals;

adjusting in frequency domain the phases and amplitudes of the N channels of data signals and outputting N channels of pre-warped electrical signals;

modulating the N channels of coherent optical carriers based on the N channels of pre-warped electrical signals and generating N channels of pre-warped optical signals; and

coupling the N channels of pre-warped optical signals into a dispersion compensation optical signal;

wherein N is a natural number greater than 1.

10. The method of claim 9, wherein the adjusting in frequency domain the phases and amplitudes of the N channels of data signals and outputting N channels of pre-warped electrical signals comprises:

adjusting in digital frequency domain the phases and amplitudes of the N channels of data signals and outputting N channels of digital pre-warped electrical signals; and

converting the N channels of digital pre-warped electrical signals into N channels of analog pre-warped electrical signals.

11. The method of claim 9, wherein the coupling the N channels of pre-warped optical signals into a dispersion compensation optical signal comprises:

adjusting the time difference among the N channels of pre-warped optical signals so that the adjusted N channels of pre-warped optical signals enter a optical coupler simultaneously; and

coupling the N channels of adjusted pre-warped optical signals into a dispersion compensation optical signal.

12. The method of claim 9, wherein the generating N channels of coherent optical carriers comprises:

generating a clock signal having a frequency which is an integer multiple of half the data signal rate;

modulating the optical carriers with the clock signal to obtain N channels of coherent optical carriers and transmitting in combination the N channels of coherent optical carriers; and

splitting the N channels of coherent optical carriers which are transmitted in combination into N channels of coherent optical carriers which are transmitted separately.