Sunghwan Rim
Pai Chai University
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Publication
Featured researches published by Sunghwan Rim.
Optics Letters | 2004
M. S. Kurdoglyan; Soo-Young Lee; Sunghwan Rim; Chil-Min Kim
We report that unidirectional lasing emission can be generated from a rounded isosceles triangular microcavity within a low nkD range, where n is the refractive index, k is the vacuum wave number, and D is the characteristic size of the microcavity. It is shown that unidirectional resonance modes have relatively high-Q values and in a nonlinear dynamic model appear as stationary lasing solutions with a low threshold. The formation of a whispering-gallery-type pattern along the rounded part on the symmetry axis is responsible for the unidirectionality of the resonances.
Optics Letters | 2006
Tea-Yoon Kwon; Soo-Young Lee; Michael S. Kurdoglyan; Sunghwan Rim; Chil-Min Kim; Young-Jai Park
The resonance patterns and lasing modes in a spiral-shaped dielectric microcavity are investigated through passive and active medium calculations. We find that the high-Q resonance modes are whispering-gallery-like modes, and these resonance modes can be easily excited as lasing modes. We also find that the quasi-scarred resonance mode, which shows strong directional emission beams from the cavity boundary, can be excited with selectively applied external pumping. Through a spectral analysis of the time evolution of the light field, the competition between these lasing modes is discussed.
Optics Letters | 2003
Muhan Choi; K. V. Volodchenko; Sunghwan Rim; Won-Ho Kye; Chil-Min Kim; Young-Jai Park; Gyu Ug Kim
Using mutually coupled nonidentical continuous-wave Nd:YAG lasers, we experimentally confirmed the recently proposed transition route from phase synchronization to complete synchronization. As evidence of this transition we obtained the probability distribution of the intermittent synchronization time near the threshold of the complete synchronization transition.
Progress of Theoretical Physics Supplement | 2007
Chil-Min Kim; Soo-Young Lee; Jung-Wan Ryu; Tae-Yoon Kwon; Sunghwan Rim; Jinhyung Lee; Jinhang Cho
We have numerically investigated the characteristics of the lasing modes in a spiralshaped microcavity laser by solving the Schrodinger-Bloch equation with the nonlinear interaction between the light field and the lasing medium. For overall uniform pumpings, we have found whispering gallery type modes with no directional emission. In case of local pumpings, however, whispering gallery type, quasi-scarred type, and complex type patterns appear in the course of time. Especially, we have also found the evidence of directional emissions from the notch part of the cavity.
Applied Physics Letters | 2003
Kijun Park; Sun-Geun Goo; Jin-Yul Yoon; Won-Ho Kye; Tae-Yoon Kwon; Sunghwan Rim; Chil-Min Kim; Young-Jai Park
We study the dynamics of the motion of a metallic particle bouncing between alternating high-voltage electrodes in a compressed SF6 gas coaxial insulator. Through the study of the bifurcation diagram and attractors, we find that the dynamics of a metallic particle develops from a stable periodic motion to chaos as the strength of the electric field increases. Based on these results, we show numerically that the chaotic motion of the particle can be stabilized by using a chaos control method.
Physical Review A | 2011
Jinhyung Lee; Sunghwan Rim; Jinhang Cho; Chil-Min Kim
We propose a simple and robust mechanism to achieve unidirectional emission in a microcavity comprised of two half-ellipses. The microcavity has two geometrical parameters, two eccentricities, which permit a control of the directional emissions. For the microcavity with two small eccentricities, the positions of secondary islands near primary islands in the survival probability distributions determine the directionality of emissions. We obtain the optimized values of the eccentricities for unidirectional emission.
Physics Letters A | 2003
Chil-Min Kim; Won-Ho Kye; Sunghwan Rim; Dong-Uk Hwang; Inbo Kim; Young-Jai Park; Eok Kyun Lee
Abstract We investigate the origin of the transition inside the desynchronization state via phase jumps in coupled chaotic oscillators. We claim that the transition is governed by type-I intermittency in the presence of noise whose characteristic relation is 〈 l 〉∝exp( α | ϵ t − ϵ | 3/2 ) for ϵ t − ϵ l 〉∝( ϵ t − ϵ ) −1/2 for ϵ t − ϵ >0, where 〈 l 〉 is the average length of the phase locking state and ϵ is the coupling strength. To justify our claim we obtain analytically the tangent point, the bifurcation point, and the return map which agree well with those of the numerical simulations.
international conference on transparent optical networks | 2007
Jinhang Cho; Jinhyung Lee; Tae-Yoon Kwon; Sunghwan Rim; Chil-Min Kim
We have numerically investigated oscillatory lasing modes in a coupled circular microcavity laser by solving the Schrodinger-Bloch equation with a nonlinear interaction between the light field and the lasing medium. Uniform pumping in the lasing process generates some special patterns as stationary ones, and the patterns are repeatedly shown during the lasing process. In this case, the patterns may be interpreted as linear combinations of the nearly degenerate modes in which the classical trajectory inside the cavity encounter the boundary of the cavity with a nearly critical angle. The numerical results are posted with a brief physical analysis.
international conference on transparent optical networks | 2006
Lei Xu; Tao Ling; Lei Shang; Qinghai Song; Wencheng Wang; Liying Liu; Soo-Young Lee; Sunghwan Rim; Chil-Min Kim
Highly collimated lasing from a series of peanut-shaped micro-cavities were observed. The lowest divergence is about 1.2deg which is as small as the pure diffraction divergence of a plane wave propagating through an opening of the cavity size. It is shown that the lensing effect of the circular boundary plays a crucial role in generating the highly collimated lasing emissions. From ray and wave dynamic analyses, we find that the peanut-shaped micro-cavity is optimal for the lasing emission of very narrow divergence
Physical Review E | 2001
Dong-Uk Hwang; Inbo Kim; Sunghwan Rim; Chil-Min Kim; Young-Jai Park
The mechanism of synchronization in the random Zaslavsky map is investigated. From the error dynamics of two particles, the structure of phase space was analyzed, and a transcritical bifurcation between a saddle and a stable fixed point was found. We have verified the structure of on-off intermittency in terms of a biased random walk. Furthermore, for the generalized case of the ensemble of particles, a modified definition of the size of a snapshot attractor was exploited to establish the link with a random walk. As a result, the structure of on-off intermittency in the ensemble of particles was explicitly revealed near the transition.