Related Experiment Video
Updated: May 14, 2026
07:45
Quasi-light Storage for Optical Data Packets
Published on: February 6, 2014
25 Tb/s transmission over 5,530 km using 16QAM at 5.2 b/s/Hz spectral efficiency.
J-X Cai1, H G Batshon, H Zhang
1TE SubCom, 250 Industrial Way West, Eatontown, NJ 07724, USA. jcai@subcom.com
Optics Express
|February 8, 2013
Summary
High-capacity optical networks achieved 5.2 b/s/Hz spectral efficiency over 5,530 km using advanced error correction. This breakthrough in optical communications demonstrates error-free transmission for future high-speed internet.
Area of Science:
- Optical Communications
- Information Theory
- Digital Signal Processing
Background:
- High spectral efficiency is crucial for increasing data transmission capacity in optical networks.
- Advanced modulation formats and error correction codes are essential for reliable long-haul transmission.
Purpose of the Study:
- To demonstrate high-capacity, long-haul optical transmission using advanced modulation and error correction.
- To investigate the impact of system parameters on optimal power spectral density.
Main Methods:
- Transmission of 250x100G PDM RZ-16QAM channels over 5,530 km.
- Utilized single-stage C-band Erbium-Doped Fiber Amplifiers (EDFAs) with 40 nm equalization.
- Employed single parity check coded modulation with iterative decoding (MAP and LDPC-based FEC).
Main Results:
- Achieved 5.2 b/s/Hz spectral efficiency with error-free transmission.
- Demonstrated successful decoding of all channels after iterative decoding.
- Observed that optimal power spectral density is largely independent of spectral efficiency, baud rate, or modulation format in dispersion uncompensated systems.
Conclusions:
- High spectral efficiency and long-haul transmission are feasible with advanced coding and modulation.
- The proposed system architecture enables robust and error-free optical data transmission.
- System design can be simplified by the near-independence of optimal power spectral density from key parameters.
Related Concept Videos
01:30Propagation Speed of Electromagnetic Waves
Electromagnetic waves are consistent with Ampere's law. Assuming there is no conduction current Ampere's law is given as:
01:16Maximum Power Transfer
Numerous practical applications within engineering disciplines, such as telecommunications, necessitate optimizing power delivery to a connected load. This pursuit, however, entails inherent internal losses, which can either equal or exceed the power supplied to the load. The Thevenin equivalent circuit is helpful in finding the maximum power a linear circuit can deliver to a load. It is assumed in this context that the load resistance can be adjusted.
By substituting the entire circuit with...
By substituting the entire circuit with...
01:31Energy Stored In A Coaxial Cable
A coaxial cable consists of a central copper conductor used for transmitting signals, followed by an insulator shield, a metallic braided mesh that prevents signal interference, and a plastic layer that encases the entire assembly.
In the simplest form, a coaxial cable can be represented by two long hollow concentric cylinders in which the current flows in opposite directions. The magnetic field inside and outside the coaxial cable is determined by using Ampère's law. The magnetic field inside...
In the simplest form, a coaxial cable can be represented by two long hollow concentric cylinders in which the current flows in opposite directions. The magnetic field inside and outside the coaxial cable is determined by using Ampère's law. The magnetic field inside...
01:22Carrier Generation and Recombination
Carrier generation is the process by which electron-hole pairs (EHPs) are created within the semiconductor. In direct-bandgap semiconductors, such as gallium arsenide (GaAs), this occurs efficiently when energy absorption prompts valence electrons to leap into the conduction band, leaving behind holes.
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
01:24The Midpoint Formula
In coordinate geometry, determining the central point between two locations is common. This central point, or midpoint, lies exactly halfway along the line segment connecting two points in a two-dimensional space. It has applications in mathematics, physics, engineering, and various planning disciplines.Given two points labeled as A (x1, y1) and B (x2, y2) on a coordinate plane, a straight line segment can be plotted between them. The midpoint, labeled point M, divides this segment into two...
01:20The Maximum Power Transfer Theorem
Consider a linear AC Thevenin equivalent circuit connected to a load impedance.
The load connected draws the current, and the circuit delivers the power to the load. The alternating current flowing through the load is determined using the rectangular form of voltages, currents, network impedance, and load impedance. The average power delivered to the load is obtained from the product of the square of current and load resistance.
The load connected draws the current, and the circuit delivers the power to the load. The alternating current flowing through the load is determined using the rectangular form of voltages, currents, network impedance, and load impedance. The average power delivered to the load is obtained from the product of the square of current and load resistance.