Index of content:
Volume 80, Issue 1, January 2009
- OPTICS; ATOMS AND MOLECULES; SPECTROSCOPY; PHOTON DETECTORS
80(2009); http://dx.doi.org/10.1063/1.3036980View Description Hide Description
We describe a simple strontium vapor cell for laser spectroscopy experiments. Strontium vapor is produced using an electrically heated commercial dispenser source. The sealed cell operates at room temperature, and without a buffer gas or vacuum pump. The cell was characterized using laser spectroscopy, and was found to offer stable and robust operation, with an estimated lifetime of . By changing the dispenser, this technique can be readily extended to other alkali and alkaline earth elements.
80(2009); http://dx.doi.org/10.1063/1.3058604View Description Hide Description
A fully automatic alignment system for a pulsed infrared laser beam (5 ns pulses, 10 Hz repetition rate, wavelength) was developed and tested. It compensates for long-term fluctuations of the beam initial position and direction—the automatic realignment is performed every 10 min, and lasts typically 1–2 min. The system adjusts the beam initial position with a maximum error of 0.5 mm (10% of the beam diameter) and the beam direction with a maximum error of . The solution is based on two InGaAs quadrant photodiodes as the position detectors and two motorized mirrors controlled by a personal computer. The signals from the quadrant detectors are processed by a peak detector and digitized by an analog to digital converter, which is synchronized with the laser pulses.
80(2009); http://dx.doi.org/10.1063/1.3058605View Description Hide Description
We present two simple cryogenic rf ion trap systems in which cryogenic temperatures and ultra high vacuum pressures can be reached in as little as 12 h. The ion traps are operated either in a liquid helium bath cryostat or in a low vibration closed cycle cryostat. The fast turn around time and availability of buffer gas cooling made the systems ideal for testing surface-electrode ion traps. The vibration amplitude of the closed cycled cryostat was found to be below 106 nm. We evaluated the systems by loading surface-electrode ion traps with ions using laser ablation, which is compatible with the cryogenic environment. Using Doppler cooling we observed small ion crystals in which optically resolved ions have a trapped lifetime over 2500 min.
80(2009); http://dx.doi.org/10.1063/1.3065027View Description Hide Description
A reliable, accurate, and inexpensive optical detector for table-top applications is described here. Based on a commercial high resolution office scanner coupled to a projection plate, the detector offers a large image plate surface, allowing recording of sizeable images without systematic errors associated with coupling optics aberrations. Several tests on distance-dependent and steady interference patterns are presented and discussed. The extension to other types of optical measurements by substituting the projection plate is proposed.
80(2009); http://dx.doi.org/10.1063/1.3073966View Description Hide Description
An advanced intensity correlation method for evaluating Poisson’s ratio of fiberlike materials is presented. The method is based on wave diffraction theory and digital image correlation (DIC) analysis. With the new method, the transverse strain of the fiberlike specimen under stretch can be conveniently and accurately determined by fitting the DIC-measured deformation distributions as a straight line following the theoretical diffraction model. The validity and flexibility of the method have been verified by numerical simulations and an experiment. The method can be readily extended to the characterizations of many fiberlike materials.