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Ultrafast coherent generation of acoustic phonons is studied in a semiconductor optical microcavity. The confinement of the light pulse amplifies both the generation and the detection of phonons. In addition, the standing wave character of the photon field modifies the generation and detection phonon bandwidth. Coherent generation experiments in an acoustic(More)
We report a direct determination of the dynamic behavior of confined acoustic phonons in nanocavities by picosecond acoustics. We provide the broadband, high resolution transmission amplitude curve in the subterahertz range, and we give evidence of resonant transmission peaks in three successive stop bands, in quantitative agreement with acoustic(More)
This paper presents an flexible architecture for Internet of things utilizing a local manager with the goal to solve many issues. The solution is described from both the system architecture and example applications. The component design and the communication between these components are introduced. The Local Manager architecture is composed of a gateway,(More)
This paper presents the design and implementation of a web-based wireless indoor climate control system. The user interface of the system is implemented as a web service. People can login to the website and remotely control the indoor climate of different locations. A wireless sensor network is deployed in each location to execute control commands. A(More)
We studied the pump coherent dynamics in a II-VI microcavity parametric amplifier, using angle-resolved four-wave mixing. The polariton parametric amplification is found to result in a strong quenching and saturation of the pump coherence lifetime above the threshold. For the polariton scattering processes that remain below the amplification threshold, we(More)
As species ranges shift due to anthropogenic change, accurate detection of hybridization between species will become increasingly important for conservation biologists. The black-capped (Poecile atricapillus) and Carolina (Poecile carolinensis) chickadee hybrid zone is difficult to study because the parental species possess similar morphologies and song is(More)
Methods to improve the reliability and optimize the system latency of our own-developed ZigBee remote sensing system are introduced in this paper. The concept of this system utilizes the ZigBee network to transmit sensor information and process them at both local and remote databases. The enhancement has been done in different parts in this system. In the(More)
The properties of optical to acoustic transduction of semiconductor superlattices have been explored for several years in the sub terahertz frequency range. Using femtosecond laser pulses focused on these structures, acoustic modes are excited with a frequency related to the periodicity of the structure stacking. We have shown that these acoustic waves can(More)
Femtosecond pump-probe experiments on a Ga0.85In0.15As nanocavity enclosed by two Ga(0.85)In(0.15)As/AlAs phonon Bragg mirrors reveal selective generation of terahertz confined acoustic modes and regular folded phonons. Selective generation of the confined modes alone is achievable for laser excitation at certain energies below the mirror absorption edges,(More)
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