Non-complementary driving technique for IQ modulator with multi-electrodes to generate high-order optical QAM signals

Area of Science:

• Optical communications
• Signal processing
• Modulation techniques

Background:

• High-order Quadrature Amplitude Modulation (QAM) is crucial for increasing data transmission rates.
• Conventional optical IQ modulators face limitations in symbol constellation density and component requirements.

Purpose of the Study:

• To propose a new configuration for generating high-order QAM signals using a multi-electrode optical IQ modulator.
• To enhance the Euclidean distance between symbols and reduce the complexity of QAM signal generation.

Main Methods:

• Utilizing an optical IQ modulator with multi-electrodes of M different lengths.
• Independently driving the four arms of the IQ modulator without push-pull configurations.
• Analyzing the impact on symbol constellation and error vector magnitude.

Main Results:

• Achieved a 1.2 times increase in Euclidean distance between symbols compared to classical IQ modulators.
• The proposed configuration requires half the value of M to achieve the same error vector magnitude as a single Mach-Zehnder modulator setup.

Conclusions:

• The proposed independent arm drive configuration offers superior performance for high-order QAM signal generation.
• This technique provides a more efficient and potentially cost-effective solution for advanced optical communication systems.