다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

J. Appl. Cryst.の発刊に際して

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

/pdf/the-observation-of-gravitational-waves-from-a-binary-black-58srpupgg9.pdf

The Observation of Gravitational Waves from a Binary Black Hole Merger

We review the field of cavity optomechanics, which explores the interaction between electromagnetic radiation and nano- or micromechanical motion This review covers the basics of optical cavities and mechanical resonators, their mutual optomechanical interaction mediated by the radiation pressure force, the large variety of experimental systems which exhibit this interaction, optical measurements of mechanical motion, dynamical backaction amplification and cooling, nonlinear dynamics, multimode optomechanics, and proposals for future cavity quantum optomechanics experiments In addition, we describe the perspectives for fundamental quantum physics and for possible applications of optomechanical devices

Cavity Optomechanics

Bose-Einstein condensation (BEC) has been observed in a dilute gas of sodium atoms. A Bose-Einstein condensate consists of a macroscopic population of the ground state of the system, and is a coherent state of matter. In an ideal gas, this phase transition is purely quantum-statistical. The study of BEC in weakly interacting systems which can be controlled and observed with precision holds the promise of revealing new macroscopic quantum phenomena that can be understood from first principles.

Bose-Einstein condensation in a gas of sodium atoms

We demonstrate a compact and robust device for simultaneous absolute frequency stabilization of three diode lasers whose carrier frequencies can be chosen freely relative to the reference. A rigid ULE multi-cavity block is employed, and, for each laser, the sideband locking technique is applied. Useful features of the system are a negligible lock error, computer control of frequency offset, wide range of frequency offset, simple construction, and robust operation. One concrete application is as a stabilization unit for the cooling and trapping lasers of a neutral atom lattice clock. The device significantly supports and improves the operation of the clock. The laser with the most stringent requirements imposed by this application is stabilized to a linewidth of 70 Hz, and a residual frequency drift less than 0.5 Hz/s. The carrier optical frequency can be tuned over 350 MHz while in lock.

/pdf/robust-frequency-stabilization-of-multiple-spectroscopy-2lx3hqcof2.pdf

Robust frequency stabilization of multiple spectroscopy lasers with large and tunable offset frequencies

The OPTIS mission is a satellite equipped with a variety of clocks and laser ranging and tracking facilities for performing improved tests of the foundations as well as predictions of special and general relativity. This mission makes advantage of the space conditions of large differences in the velocity and the gravitational potential. Here, we report on recent progress made in the studies of the behavior of the resonator in the field of a gravity gradient.

OPTIS: High-Precision Tests of Special and General Relativity in Space

A widely tunable difference frequency generation based mid-infrared spectrometer for the detection of sulfur dioxide (SO2), nitrous oxide (N2O), and methane (CH4) above 7 µm has been developed for industrial applications.

A Widely Tunable CW Mid-Infrared Spectrometer Based on Difference Frequency Generation in Orientation-Patterned GaAs

resonators in the near-infrared spectral range

We have experimentally determined the quantum statistica of the radiation field for strongly squeezed states with and without coherent excitation and for coherent states. For this purpose we developed a stable source of continuous-wave squeezed light at 1064 nm, using a monolithic lithium niobate optical parametric amplifier (OPA). This device is pumped by an externally frequency-doubled, continuous-wave NdYAG laser. For the generation of squeezed vacuum the OPA is pumped below its threshold, while for the generation of phase-squeezed arid amplitude-squeezed light the OPA is seeded by a weak signal which is parametrically amplified and deamplified, respectively. The output signal field is detected using a balanced heterodyne detector in which the signal field is overlayed with a strong local oscillator. The difference current of the two highly efficient photodetectors is amplified, frequency downconverted, low pass filtered and recorded with a digital oscilloscope. The time resolved noise current traces provide the full statistical distributions for the quadrature components of the light field. Using reconstruction algorithms these distributions are transformed to the corresponding position-momentum Wigner function [I] and to the density matrix in Fa& space [21. This latter evaluation determines the photon number distribution and the phase distribution for the light field. For the squeezed vacuum state strong oscillations in the photon number distribution aze observed. These can he explained as arising from interference in phase space, a true quantum phenomenon. [3] '

Stephan Schiller

Papers

Robust frequency stabilization of multiple spectroscopy lasers with large and tunable offset frequencies

OPTIS: High-Precision Tests of Special and General Relativity in Space

A Widely Tunable CW Mid-Infrared Spectrometer Based on Difference Frequency Generation in Orientation-Patterned GaAs

resonators in the near-infrared spectral range

Quantum Statistics of Bright Squeezed Light and Squeezed Vacuum