SOA Amplitude to Phase Modulation Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing coherent data optical transmitters with phase modulation using semiconductor optical amplifiers (SOAs) suffer from residual amplitude modulation, requiring costly and complex equipment.
Innovation Solution
An optical network component comprising a semiconductor optical amplifier that converts amplitude modulated signals to phase modulated signals with suppressed amplitude modulation, utilizing a single low-cost light source and common components, such as electro absorption modulators and circulators, without needing a chirp-free modulator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a semiconductor optical amplifier is used for phase modulation conversion, then phase modulation is achieved, but residual amplitude modulation remains
Solution Approach 1:
The patent divides the signal processing into two separate functional stages: first an amplitude modulator creates the amplitude modulated signal, then a semiconductor optical amplifier converts it to phase modulation. This segmentation allows each component to optimize its function while the system as a whole achieves clean phase modulation with minimal residual amplitude modulation.
Solution Approach 2:
The patent exploits the nonlinear optical properties of the semiconductor optical amplifier by operating it in a specific regime where it converts amplitude modulated signals to phase modulated signals. By controlling the operating parameters (bias current, input power levels) of the SOA, the system achieves efficient amplitude-to-phase conversion while suppressing residual amplitude modulation.
2Manufacturing precision
If costly and complex equipment is used to eliminate residual amplitude modulation, then modulation purity is improved, but system cost and complexity increase
Solution Approach 1:
The semiconductor optical amplifier inherently performs the function of converting amplitude modulation to phase modulation and simultaneously suppressing residual amplitude modulation through its nonlinear optical characteristics. The system uses itself to solve the problem rather than requiring external complex equipment, achieving modulation purity through the SOA's intrinsic properties when operated in the appropriate regime.
Solution Approach 2:
By optimizing the operating parameters of the semiconductor optical amplifier (bias point, input signal power, device structure), the system achieves effective suppression of residual amplitude modulation without requiring additional complex components. The parameter optimization allows the SOA to self-correct the modulation purity issue.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Efficient conversion of amplitude to phase modulation with minimal residual amplitude modulation, reducing costs and complexity, and providing both amplification and modulation functionality with a single light source.
Implementation Method 1
Hsiao-Yun Yu; Mahgerefteh, D.; Cho, P. S.; Goldhar, J.: Optimization of the frequency response of a semiconductor optical amplifier wavelength converter using a fiber Bragg grating, Journal of Lightwave Technology (1999), vol. 17, issue 2, p. 308-315, JLTEDG ISSN 0733-8724 discloses a cross-gain modulation in a semiconductor optical amplifier (SOA) for an all-optical wavelength conversion.
Implementation Method 2
An amplitude modulated signal with a predetermined level fed to a SOA results in a phase modulation provided by the SOA. Hence, the amplitude modulation conveyed to the SOA's input provides a phase modulation at the SOA's output.
Data Source
AI summary
An optical network component is provided comprising a semiconductor optical amplifier with an input and an output, wherein the input is connected to a light source, wherein the output is connected to an amplitude modulator, wherein the semiconductor optical amplifier converts an amplitude modulated signal from the amplitude modulator to a phase modulated signal and provides the phase modulated signal at its output. Also, a transmitter comprising at least one such optical network component is suggested.