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Fast square-oscillations in semiconductor VCSELs with delayed orthogonal polarization feedback
Optics Express
|June 14, 2025
Summary
This study demonstrates fast square oscillations in semiconductor lasers using delayed feedback. The findings offer a novel all-optical method for generating specialized signals for optical communications and computing.
Area of Science:
- Optics and Photonics
- Nonlinear Dynamics
- Semiconductor Lasers
Background:
- Semiconductor lasers exhibit complex nonlinear dynamics.
- Controlling laser output polarization is crucial for applications.
Purpose of the Study:
- To experimentally investigate the generation of self-sustained and fast square oscillations.
- To explore the role of delayed orthogonal polarization feedback in VCSELs.
- To understand the mechanisms behind low-frequency switching and fast oscillations.
Main Methods:
- Experimental setup using semiconductor Vertical-Cavity Surface-Emitting Lasers (VCSELs).
- Application of delayed orthogonal polarization feedback.
- Inclusion of a half-wavelength (λ/2) plate.
- Analysis of nonlinear dynamics and frequency beating.
Main Results:
- Generation of self-sustained and fast square oscillations.
- Low-frequency switching attributed to TE/TM mode rotation with long delay.
- Fast oscillations linked to frequency beating between TE and TM modes, modified by the λ/2 plate.
Conclusions:
- The study deepens the understanding of laser nonlinear dynamics.
- An all-optical method for producing specialized signals is presented.
- Potential applications in optical communications and photonic computing.
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