Browsing by Author "Otsuka, K"

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Chaos synchronization in a mutually coupled laser array subjected to self-mixing modulation
(2004-07-01)
Kawai, R
;
Lih, JS
;
Ko, JY
;
Chern, JL
;
Otsuka, K
This tutorial presents a detailed description of experiments, simulations, and characterizations of chaos synchronization phenomena in the model of a mutually coupled microchip solid-state laser array subjected to self-mixing feedback modulation. We demonstrate a transition to synchronized chaos by the method of 'phase squeezing' with increasing field overlap between the two lasers. This phenomenon is well reproduced by numerical simulation of model equations. It is also shown that low energy variation as well as high disorder are concurrently established in synchronized chaos in the present system. The deterministic random switching (i.e., chaotic itinerancy) among phase-squeezed states and synchronized chaos states is numerically demonstrated in a transition region from a phase-squeezed state to a synchronized state. We characterize observed behaviours; using such methods as singular value deposition (SVD), joint time-frequency analysis (JTFA) introducing a similarity function, and coarse-grained information transfer rate (CITR) analysis of long-term experimental or numerical time series, and discuss the physical significance of observed nonlinear dynamics in conjunction with chaos synchronization in mutually coupled lasers.
Phase-noise-driven instability in a single-mode microchip Nd : YVO4 laser with feedback
(2001-09-01)
Lim, TS
;
Yang, TH
;
Chern, JL
;
Otsuka, K
;
光電工程學系
We report the instability behaviors of a single-mode microchip solid-state laser subjected to external feedback. Two kinds of instabilities, random chaotic burst generations and random sinusoidal burst generations, were observed experimentally in an LD-pumped microchip Nd:YVO4 single-mode solid-state laser with fiber feedback. These results are totally different form those observed in laser diodes with delay feedback systems, which have been widely studied in last decades. Main features were reproduced numerically by utilizing the Lang-Kobayashi equations with phase noise, indicating phase-noise-driven dynamic instabilities.
Stokes-like emissions from laser-diode-pumped microchip neodymium-doped solid-state lasers
(2002-07-01)
Chern, JL
;
Kubota, T
;
Lim, TS
;
Otsuka, K
;
光電工程學系
Stokes-like IR (1560-1600-nm) emissions, which have been observed in laser-diode- (LD-) pumped microchip Nd-doped lasers, are re-examined experimentally. Dependences of IR emissions on pump wavelengths, pump densities, and operating temperatures are studied. The response of IR emissions to coherent probe-beam injection is investigated by use of a tunable LD light source. Optical phonons emitted through Auger recombination processes that result from LD high-density pumping are proposed to induce resonant intracavity stimulated phonon-sideband emissions. (C) 2002 Optical Society of America.