4 research outputs found
Acousto-optic and opto-acoustic modulation in piezo-optomechanical circuits
Acoustic wave devices provide a promising chip-scale platform for efficiently
coupling radio frequency (RF) and optical fields. Here, we use an integrated
piezo-optomechanical circuit platform that exploits both the piezoelectric and
photoelastic coupling mechanisms to link 2.4 GHz RF waves to 194 THz (1550 nm)
optical waves, through coupling to propagating and localized 2.4 GHz acoustic
waves. We demonstrate acousto-optic modulation, resonant in both the optical
and mechanical domains, in which waveforms encoded on the RF carrier are mapped
to the optical field. We also show opto-acoustic modulation, in which the
application of optical pulses gates the transmission of propagating acoustic
waves. The time-domain characteristics of this system under both pulsed RF and
pulsed optical excitation are considered in the context of the different
physical pathways involved in driving the acoustic waves, and modeled through
the coupled mode equations of cavity optomechanics.Comment: 8 pages, 6 figure
A De Novo Centric Fission of Chromosome 11 in a Patient with Recurrent Miscarriages
We report on a de novo centric fission of chromosome 11 in a healthy female referred for chromosome analysis due to recurrent miscarriages. Both fission products were mitotically stable. This centric fission of chromosome 11 appears to have no clinical significance for this patient other than recurrent miscarriages
Effects of Thermal Annealing on Optical and Microscopic Ferromagnetic Properties in InZnP:Ag Nano-Rods
InZnP:Ag nano-rods fabricated by the ion milling method were thermally annealed in the 250~350 °C temperature range and investigated the optimum thermal annealing conditions to further understand the mutual correlation between the optical properties and the microscopic magnetic properties. The formation of InZnP:Ag nano-rods was determined from transmission electron microscopy (TEM), total reflectivity and Raman scattering analyses. The downward shifts of peak position for LO and TO modes in the Raman spectrum are indicative of the production of Ag ion-induced strain during the annealing process of the InZnP:Ag nano-rod samples. The appearance of two emission peaks of both (A0 X) and (e, Ag) in the PL spectrum indicated that acceptor states by Ag diffusion are visible due to the effective incorporation of Ag-creating acceptor states. The binding energy between the acceptor and the exciton measured as a function of temperature was found to be 21.2 meV for the sample annealed at 300 °C. The noticeable MFM image contrast and the clear change in the MFM phase with the scanning distance indicate the formation of the ferromagnetic spin coupling interaction on the surface of InZnP:Ag nano-rods by Ag diffusion. This study suggests that the InZnP:Ag nano-rods should be a potential candidate for the application of spintronic devices
Observation of a Biexciton Wigner Molecule by Fractional Optical Aharonov-Bohm Oscillations in a Single Quantum Ring
The
Aharonov-Bohm effect in ring structures in the presence
of electronic correlation and disorder is an open issue. We report
novel oscillations of a strongly correlated exciton pair, similar
to a Wigner molecule, in a single nanoquantum ring, where the emission
energy changes abruptly at the transition magnetic field with a fractional
oscillation period compared to that of the exciton, a so-called fractional
optical Aharonov-Bohm oscillation. We have also observed modulated
optical Aharonov-Bohm oscillations of an electron–hole pair
and an anticrossing of the photoluminescence spectrum at the transition
magnetic field, which are associated with disorder effects such as
localization, built-in electric field, and impurities