Unlock instant, AI-driven research and patent intelligence for your innovation.

Mach-zehnder optical modulator and optical modulation method

A modulator and optical modulation technology, applied in the direction of instruments, optics, light guides, etc., can solve the problems of signal quality degradation, small power difference, and reduced signal quality.

Pending Publication Date: 2020-09-01
FUJITSU OPTICAL COMPONENTS LTD
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

As a result, since the multi-valued signal is input within the same light level, the power difference between the respective light levels is small, and the signal quality is degraded due to the change of the light level due to the change of the driving signal
Therefore, in optically modulated signals of four or more values, dithering the signal degrades the signal quality

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Mach-zehnder optical modulator and optical modulation method
  • Mach-zehnder optical modulator and optical modulation method
  • Mach-zehnder optical modulator and optical modulation method

Examples

Experimental program
Comparison scheme
Effect test

no. 1 approach

[0025] figure 1 is an illustration of an example of the optical transmission device 1 according to the first embodiment. figure 1 The optical transmission device 1 shown is an optical transceiver supporting 400 Gbps. The optical transmission device 1 includes a transmission DSP 11 , an LD driving unit 12 , an MZI driving unit 13 and an optical multiplexer 14 . Furthermore, the optical transmission device 1 includes an optical demultiplexer 15 , a photodiode (PD) group 16 , a transimpedance amplifier (TIA) group 17 , a receiving DSP 18 and a microcontroller unit (MCU) 19 .

[0026] The sending DSP 11 receives eight PAM4 electrical signals, and outputs two PAM4 electrical signals as a driving signal to the MZI driving unit 13 . The LD driving unit 12 includes first to fourth LDs 12A to 12D. The MZI drive unit 13 includes first to fourth MZIs 13A to 13D. For each group of PAM4 electrical signals, an LD driving unit 12 and an MZI driving unit 13 are arranged. The first LD 1...

no. 2 approach

[0071] Figure 11 is an illustration of an example of the transmission DSP 11 , the LD drive unit 12 , the MZI drive unit 13 , and the MCU 19 in the optical transmission device 1A of the second embodiment. Reference numerals common to the optical transmission device 1 of the first embodiment are assigned to common components, and thus descriptions of duplicate components and operations are omitted.

[0072] The first MZI 13A has an LSB portion 22A and an MSB portion 22B arranged in each of the upper arm 21A and the lower arm 21B of the optical waveguide 21 . The first setting unit 33A sets the ratio of the electrode length of the LSB portion 22A of the upper arm 21A to the electrode length of the MSB portion 22B of the upper arm 21A to 1:2. Furthermore, the first setting unit 33A sets the amplitude ratio of the dither signal of the LSB drive signal of the upper arm 21A to the dither signal of the MSB drive signal of the upper arm 21A to 1:2. The first setting unit 33A sets t...

no. 3 approach

[0087] Figure 12 is an illustration of an example of the transmission DSP 11 , the LD drive unit 12 , the MZI drive unit 13 , and the MCU 19 in the optical transmission device 1B of the third embodiment. In the optical transmission device 1B, the electrode length ratio of the LSB portion 22A to the MSB portion 22B of the first MZI 13A is set to 1:n, and the dithering signal superimposed on the LSB driving signal and the dithering signal superimposed on the MSB driving signal The magnitude ratio is set to n:1. The first generating unit 32A of the first MZI 13A includes a dithering signal generating unit 51, an n-fold amplifier 52A, a first superimposing unit 53A, a second superimposing unit 53B, a first amplifying unit 56A, a second amplifying unit 56B, and a bias T 57

[0088] The dithering signal generation unit 51 generates a reference dithering signal. The n-fold amplifier 52A amplifies the reference dither signal generated by the dither signal generating unit 51 by n-fo...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a Mach-Zehnder optical modulator and an optical modulation method. The Mach-Zehnder optical modulator creates a first driving signal to be applied to a first section, and a second driving signal to be applied to a second section, and includes a generator, an optical modulator, and a setting unit. The generator generates a first dither signal and a second dither signal. The optical modulator optical modulates an optical signal into a quaternary or more value optical modulation signal by applying the first driving signal superimposed by the first dither signal, and by applying the second driving signal superposed by the second dither signal. The setting unit sets, when a length of the second section is n times as long as the first section, the first dither signal and the second dither signal to have a same phase, and sets such that an amplitude of the first dither signal is n times as large as that of the second dither signal.

Description

technical field [0001] Embodiments discussed herein relate to Mach-Zehnder light modulators and light modulation methods. Background technique [0002] For example, an optical module supporting 400G Ethernet (Ethernet, registered trademark) has been being developed, and in order to increase a bit rate, there is a standard using Pulse Amplitude Modulation 4 (PAM4). A 400G optical transmission device using PAM4 uses a PAM4 signal at a baud rate of 25G for input and output of an electrical signal, and inputs and outputs an electrical signal of 50 gigabits per second (Gbps) per lane of the electrical signal, for example, by Eight lanes of 400Gbps electrical signals are used. In the input and output of optical signals, it is possible to realize PAM4 signals carrying 50G baud rate on one optical wavelength, and 100Gbps on each wavelength, that is, optical reception and optical transmission of 400Gbps using four wavelengths. [0003] In such an optical transmission device, for ex...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): G02F1/225
CPCG02F1/225G02F1/2257G02F1/0121G02F1/0123H04B10/50575H04B10/516G02F1/212G02B6/29352
Inventor 渡边学
Owner FUJITSU OPTICAL COMPONENTS LTD
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com