We experimentally observe the lasing of a single-mode group in a rounded D-shape InGaAsP semiconductor microcavity laser when the cavity is fully chaotic. Although there are numerous unstable periodic orbits and marginally unstable periodic orbits, the lasing mode group is localized on a pentagonal period-5 unstable periodic orbit and marginally unstable periodic orbits for each rounded D-shape microcavity laser with parameters r=0.85R, φ= 5° and r=0.5R, φ=80°, respectively, near above the lowest threshold for CW current injection. By means of numerical analyses with ray and wave dynamics, we have theoretically predicted the dominant lasing of the pentagonal mode group by considering the linear gain condition at the lowest threshold condition. We calculate the threshold parameters depending on the effective pumping region for each periodic orbit, and have obtained that the resonance modes localized on the pentagonal periodic orbits have the lowest threshold parameter for our experimental condition, which has a 3μm inward gap between the current contact region and the side-wall of the microcavity. Consequently, we have confirmed that the path length and unidirectional emission from the experimental the result well coincide with our theoretical prediction.
Table Of Contents
Abstract Contents List of Figures I. Introduction 1
II. Lasing of scarred mode near above threshold in a rounded D-shape microcavity laser 3 2.1 Ray dynamical analysis and unstable periodic orbits 5 2.2 Wave analysis for the threshold pumping strength 7 2.3 Fabrication and experimental results 11 2.4 Discussion 15 2.4.1 Quality factor of the scarred mode 15 2.4.2 Unidirectional emission from a scarred mode lasing 17 2.5 Conclusion 17
III. Lasing modes localized on marginally unstable periodic orbits in arounded D-shape microcavity laser 20 3.1 Semiconductor RDS microcavity laser with an inward gap 21 3.2 Unstable periodic orbits in a ray dynamical simulation 23 3.3 Resonances localized on MUPOs and UPOs 27 3.4 Linear gain condition with a single-mode approximation 29 3.4.1 The threshold condition depending on the classical path of the periodic orbits 29 3.4.2 The threshold condition depending on the spatial wave function localized on the periodic orbits 30 3.4.3 The effective pumping region due to the fabricating configuration 33 3.5 Experimental results and emission characteristics 35 3.6 Conclusion 39
IV. Methods 40 4.1 Fabrication of the two dimensional semiconductor microcavity laser 40 4.2 Experimental set-up configuration 42 References 44 Summary (요약문) 52
