Quantum_Dot_Laser_Chaos_Presentation.pptx

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1. Impact of Optical Injection Strength on Bifurcation and Chaos Onset in Quantum-Dot Semiconductor Lasers Based on Chapter 6 of Junji Ohtsubo's 'Semiconductor Lasers: Stability, Instability and Chaos' (4th Edition)

2. Introduction Optical injection: injecting light from a master laser into a slave laser. Leads to dynamic behaviors: frequency locking, period doubling, chaos. Quantum-dot (QD) lasers: enhanced nonlinear effects due to discrete energy levels.

3. System Setup Master-slave laser configuration. Key Parameters: - Injection strength (K) - Frequency detuning (Δν) - Bias current (J / J_th) [Insert schematic of experimental setup]

4. Bifurcation Overview Dynamics as injection strength increases: - Stable locking - Periodic oscillations (P1, P2) - Quasi-periodicity (QP) - Chaos [Insert bifurcation diagram figure]

5. Quasi-Periodic Route Transition to chaos via quasi-periodicity. Observed in bifurcation diagrams as injection strength increases. [Insert figure showing QP region]

6. Time-Series and RF Spectrum At Δν = +1 GHz: - Irregular intensity (chaos) - Broad RF spectrum [Insert time-domain and RF plots from experiment]

7. Period-Doubling to Chaos Cascading period-doubling route to chaos. Subharmonic generation observed in intensity output. [Insert bifurcation cascade image]

8. Theoretical Model Lang-Kobayashi-type rate equations: - Photon density - Carrier density - Optical phase Inclusion of α-factor for nonlinear gain-phase coupling.

9. QD Laser Specifics QD lasers show reduced α-factor sensitivity. Require quantum-level modeling for accurate prediction. [Insert diagram comparing QD and conventional lasers]

10. Applications Chaos-based secure communication. Microwave signal generation. Random number generation. Chaos suppression for stable laser operation.

11. Summary Table Parameter Effect on Dynamics K (Injection Strength) From locking to chaos Δν (Detuning) Chooses bifurcation path α-factor Affects stability thresholds

12. References Ohtsubo, J. (2017). Chapter 6: Dynamics in Semiconductor Lasers with Optical Injection. ResearchGate and MDPI figures on injection and bifurcation. QD modeling papers and experimental results.