Browsing by Author "Otsuka, Kenju"

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Composite lattice pattern formation in a wide-aperture thin-slice solid-state laser with imperfect reflective ends
(2006-11-24)
Otsuka, Kenju
;
Miyasaka, Yoshihiko
;
Narita, Tatsuro
;
Chu, Shu-n Chu
;
Lin, Chi-Ching
We observed self-formations of multiple lasing channels and two-dimensional lasing patterns consisting of composite local modes having different lasing frequencies in a laser-diode-pumped wide-aperture thin-slice solid-state laser with imperfect reflective end surfaces. Global patterns resembling higher-order Hermite-Gaussian modes or possessing N-fold rotational symmetries were experimentally shown to appear due to the standard polished surface roughness of closely spaced reflective ends and nonlinear modal interactions.
Nonlinear dynamics in thin-slice Nd : YAG ceramic lasers: Coupled local-mode laser model
(2006-08-21)
Otsuka, Kenju
;
Narita, Tatsuro
;
Miyasaka, Yoshihiko
;
Lin, Chi-Ching
;
Ko, Jing-Yuan
The authors propose a coupled spatially distributed local-mode laser model for understanding self-induced high-speed modulations in Nd:YAG ceramic lasers with laser-diode end pumping, which critically depend on pump positions. In addition to complicated high-speed modulations, quasiperiodic and chaotic relaxation oscillations have been demonstrated experimentally and reproduced by numerical simulation of the model of coupled local-mode lasers. Q-switching-like periodic spiking pulsations have been also observed and reproduced numerically by assuming saturable absorber type of inclusions in grain boundaries.