Related Experiment Video
Updated: Jul 4, 2026
09:43
Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
Published on: March 20, 2017
Optical multicarrier generator for radio-over-fiber systems
Y Kim1, S Doucet, M E Mousa Pasandi
1Centre d'optique, photonique et laser, Department of Electrical and Computer Engineering, Université Laval, Québec, Canada, G1V 0A6.
Optics Express
|June 11, 2008
Summary
We developed a novel optical multicarrier generator for radio-over-fiber systems using a phase-modulated laser and chirped fiber Bragg gratings. This method achieves a flattened spectrum, enabling high-quality signal transmission with improved error performance.
Area of Science:
- Photonics
- Optical Communications
- Signal Processing
Background:
- Radio-over-fiber (ROF) systems require stable and spectrally flat optical multicarrier sources.
- Existing methods for multicarrier generation often suffer from spectral unevenness and complexity.
Purpose of the Study:
- To propose and demonstrate a new optical multicarrier generation method for ROF systems.
- To achieve a spectrally flattened multicarrier signal with high optical signal-to-noise ratio (OSNR).
- To evaluate the performance of the generated multicarrier source for wireless signal transmission.
Main Methods:
- Utilized a phase-modulated laser source.
- Employed two chirped fiber Bragg gratings (CFBGs) as spectral flattening filters.
- Spectrally tailored CFBGs to equalize the laser spectrum.
- Integrated the generator as an externally modulated source for 802.11 compliant signals.
Main Results:
- Demonstrated a flattened multicarrier spectrum with 7 carriers at 12.5 GHz spacing.
- Achieved less than 2 dB peak-to-peak spectral variations.
- Obtained an OSNR of 40 dB.
- Measured an average error vector magnitude (EVM) of 32.8 dB, outperforming a tunable laser source (36.2 dB).
Conclusions:
- The proposed optical multicarrier generation method effectively produces a spectrally flattened signal suitable for ROF applications.
- The demonstrated performance, particularly the low EVM, indicates the potential for error-free transmission.
- This technique offers a promising solution for advanced optical wireless communication systems.
Related Concept Videos
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...
01:31Energy 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...
01:10Generating Electromagnetic Radiations
The German physicist Heinrich Hertz (1857–1894) was the first to generate and detect certain types of electromagnetic waves in the laboratory. Starting in 1887, he performed a series of experiments that confirmed the existence of electromagnetic waves and verified that they travel at the speed of light. Hertz used an alternating-current RLC (resistor-inductor-capacitor) circuit that resonated at a known frequency and connected it to a loop of wire. High voltages induced across the gap in the...
01:21Properties of Fourier Transform I
The application of Fourier Transform properties in radio broadcasting is multifaceted, enabling significant advancements in the way signals are transmitted and received. Key areas where these properties are utilized include simultaneous multi-channel transmission, audio clip speed adjustments, live broadcast delays for different time zones, audio frequency adjustments, and signal demodulation.
In radio broadcasting, multiple audio signals often need to be transmitted simultaneously. The Fourier...
In radio broadcasting, multiple audio signals often need to be transmitted simultaneously. The Fourier...
01:23Transmission Line Design Considerations
Aluminum has become the material of choice for overhead transmission lines, surpassing copper due to its abundance and cost-effectiveness. The most prevalent type is the aluminum conductor, steel-reinforced (ACSR), which combines aluminum strands around a steel core. Other variants include all-aluminum conductors (AAC), all-aluminum alloy conductors (AAAC), aluminum conductor alloy-reinforced (ACAR), and aluminum-clad steel conductors. Advanced designs, such as aluminum conductors with steel...
01:22Energy Carried By Electromagnetic Waves
Anyone who has used a microwave oven knows there is energy in electromagnetic waves. Sometimes, this energy is obvious, such as in the summer sun's warmth. At other times, it is subtle, such as the unfelt energy of gamma rays, which can destroy living cells. Electromagnetic waves bring energy into a system through their electric and magnetic fields. These fields can exert forces and move charges in the system and, thus, do work on them. However, there is energy in an electromagnetic wave,...