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Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
Experimental demonstration of coherent OCDMA using heterodyne detection
Yi Yang1, Keith G Petrillo, Hong-Fu Ting
1Department of Electrical and Computer Engineering, The Johns Hopkins University, 3400 N. Charles St., Barton 105, Baltimore, Maryland 21218, USA.
Optics Letters
|July 2, 2013
Summary
This study demonstrates a novel optical code division multiple access (OCDMA) system that eliminates interference and noise. The advanced scheme achieves high data rates with excellent signal quality for multiple users.
Area of Science:
- Optical communications
- Signal processing
- Telecommunications engineering
Background:
- Multiple access interference (MAI) and speckle noise degrade performance in optical code division multiple access (OCDMA) systems.
- Existing OCDMA schemes often require complex techniques like phase locking or thresholding and gating to mitigate these issues.
- A need exists for a simpler, more robust OCDMA approach.
Purpose of the Study:
- To experimentally demonstrate a practical, fully coherent OCDMA scheme.
- To achieve full suppression of multiple access interference (MAI) and speckle noise.
- To validate the performance of the proposed scheme without relying on phase locking or thresholding and gating.
Main Methods:
- Utilizing an optical comb generator as the source.
- Implementing spectral phase encoding for signal manipulation.
- Employing a heterodyne receiver with balanced detection for signal recovery.
- Testing a four-user configuration at 50% system load.
Main Results:
- Successful experimental demonstration of the proposed OCDMA scheme.
- Complete suppression of MAI and speckle noise achieved.
- A signal-to-MAI ratio of 648 was recorded at a bit error rate of 10^-7.
- System operated at 4.5 Gbits/s per user.
Conclusions:
- The presented fully coherent OCDMA scheme is practical and effective.
- The scheme successfully eliminates MAI and speckle noise without complex processing.
- This breakthrough offers a significant advancement in high-speed, interference-free optical networking.
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