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Simultaneous implementation of XOR and XNOR operations using a directed logic circuit based on two microring
Lei Zhang1, Ruiqiang Ji, Yonghui Tian
1Optoelectronic System Laboratory, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China.
Optics Express
|April 1, 2011
Summary
This study demonstrates simultaneous XOR and XNOR logic operations using cascaded microring resonators (MRRs). The optical logic circuit operates at 10 kbit/s, showing potential for high-speed integrated photonic circuits.
Area of Science:
- Photonics and optical computing
- Integrated optics
- Nonlinear optics
Background:
- Microring resonators (MRRs) are key components in integrated photonics for wavelength filtering and manipulation.
- Thermo-optic modulation offers a stable method for controlling MRR properties.
- Implementing complex logic operations on a single chip is crucial for advancing optical computing.
Purpose of the Study:
- To demonstrate simultaneous XOR and XNOR logic operations using cascaded MRRs.
- To investigate the potential for high-speed operation in such photonic logic circuits.
- To analyze the spectral characteristics and performance limitations of the fabricated device.
Main Methods:
- Fabrication of a directed logic circuit using two cascaded microring resonators (MRRs).
- Thermo-optic modulation of MRRs using electrical signals to represent logic operands.
- Experimental demonstration of simultaneous bitwise XOR and XNOR operations at 10 kbit/s.
- Analysis of spectral characteristics using the scattering matrix method, treating the circuit as a Mach-Zehnder interferometer (MZI).
Main Results:
- Simultaneous XOR and XNOR operations were successfully implemented at two ports of the MRR-based circuit.
- The circuit demonstrated operation at 10 kbit/s in two distinct modes.
- The potential for high-speed operation was indicated through analysis of plasma dispersion and electric field effects.
- Spectral degradation was observed and linked to the length difference between the MZI arms.
Conclusions:
- The cascaded MRR circuit effectively performs simultaneous XOR and XNOR logic operations.
- The demonstrated thermo-optic modulation approach is suitable for integrated photonic logic.
- Further optimization, particularly addressing spectral degradation related to arm length differences, is needed for enhanced performance.
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