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Effects of self-mixing interference on gain-coupled distributed-feedback lasers
Optics Express
|June 5, 2009
Summary
Gain-coupled distributed-feedback (DFB) lasers offer high-accuracy self-mixing sensors. Analysis shows their oscillation frequency and threshold gain are minimally affected by self-mixing interference, outperforming other laser types.
Area of Science:
- Photonics
- Laser Physics
- Optical Sensing
Background:
- Self-mixing interference is a significant factor in laser sensor performance.
- Gain-coupled (GC) distributed-feedback (DFB) lasers are potential candidates for advanced optical sensing applications.
Purpose of the Study:
- To theoretically analyze the impact of self-mixing interference on GC DFB lasers.
- To compare the self-mixing performance of GC DFB lasers with other laser configurations like phase-shifted DFB and Fabry-Perot lasers.
Main Methods:
- Utilized coupled-wave theory to deduce oscillation frequency and threshold gain variations.
- Performed numerical analysis to investigate the influence of key laser parameters and external reflector properties.
- Compared theoretical and numerical results with those of lambda/4 phase-shifted DFB and Fabry-Perot lasers.
Main Results:
- The study theoretically deduced oscillation frequency and threshold gain variations in GC DFB lasers due to self-mixing interference.
- Key parameters influencing self-mixing effects, including coupling length, linewidth enhancement factor, and external reflector reflectivity, were analyzed.
- GC DFB lasers demonstrated superior performance in self-mixing interference compared to lambda/4 phase-shifted DFB and Fabry-Perot lasers.
Conclusions:
- Gain-coupled DFB lasers are highly suitable for developing high-accuracy self-mixing sensors.
- The theoretical framework provides insights into optimizing GC DFB lasers for robust optical sensing applications.
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