13 research outputs found
Quasi-Eigenstate Evolution in Open Chaotic Billiards
We experimentally studied evolution of quasi-eigenmodes as classical dynamics
undergoing a transition from being regular to chaotic in open quantum
billiards. In a deformation-variable microcavity we traced all high-Q cavity
modes in a wide range of frequency as the cavity deformation increased. By
employing an internal parameter we were able to obtain a mode-dynamics diagram
at a given deformation, showing avoided crossings between different mode
groups, and could directly observe the coupling strengths induced by ray chaos
among encountering modes. We also show that the observed mode-dynamics diagrams
reflect the underlying classical ray dynamics in the phase space.Comment: 4 pages, 4 figure
Chaos-assisted nonresonant optical pumping of quadrupole-deformed microlasers
Efficient nonresonant optical pumping of a high-Q scar mode in a
two-dimensional quadrupole-deformed microlaser has been demonstrated based on
ray and wave chaos. Three-fold enhancement in the lasing power was achieved at
a properly chosen pumping angle. The experimental result is consistent with ray
tracing and wave overlap integral calculations.Comment: 3 pages, 5 figure
Development of deformation-tunable quadrupolar microcavity
We have developed a technique for realizing a two-dimensional quadrupolar
microcavity with its deformation variable from 0% to 20% continuously. We
employed a microjet ejected from a noncircular orifice in order to generate a
stationary column with modulated quadrupolar deformation in its cross section.
Wavelength red shifts of low-order cavity modes due to shape deformation were
measured and were found to be in good agreement with the wave calculation for
the same deformation, indicating the observed deformation is quadrupolar in
nature.Comment: 7 pages, 6 figures, intended for Rev. Sci. Instu
Pump-Induced Dynamical Tunneling in a Deformed Microcavity Laser
Pump-induced dynamical tunneling has been observed in free-space resonant optical pumping of a deformed microcavity by employing excitation spectroscopy. A focused-pump beam was injected into the cavity by refraction and then coupled to a high-Q cavity mode via dynamical tunneling. Pump-coupling efficiency as high as 50% and an effective coupling constant responsible for the tunneling were obtained from the observed pumping efficiency with a mode-mode coupling modelopen2