Faraday spectroscopy of atoms confined in a dark optical trap

We demonstrate Faraday spectroscopy with high duty cycle and sampling rate using atoms confined to a blue-detuned optical trap. Our trap consists of a crossed pair of high-charge-number hollow laser beams, which forms a dark, box-like potential. We have used this to measure transient magnetic fields in a 500-micron-diameter spot over a 400 ms time window with nearly unit duty cycle at a 500 Hz sampling rate. We use these measurements to quantify and compensate time-varying magnetic fields to ~10 nT per time sample.Comment: 6 pages, 8 figures Accepted in Phys. Rev.

Magnetically-controlled velocity selection in a cold atom sample using stimulated Raman transitions

We observe velocity-selective two-photon resonances in a cold atom cloud in the presence of a magnetic field. We use these resonances to demonstrate a simple magnetometer with sub-mG resolution. The technique is particularly useful for zeroing the magnetic field and does not require any additional laser frequencies than are already used for standard magneto-optical traps. We verify the effects using Faraday rotation spectroscopy.Comment: 5 pages, 6 figure

Depth-Resolved Subsurface Defect Detection in Ceramics Using Optical Gating Techniques

Components made from advanced ceramics materials find widespread use in many industrial and military applications. However, the presence of defects in the bulk and on the surface of the ceramic parts can alter their operation and lead to a reduced lifetime or a catastrophic failure. These defects may include various inclusions, inherent powder defects, poorly distributed second phase material, as well as voids and cracks. They can be introduced at each stage of the manufacturing process. Near-surface defects are particularly critical in many applications since the stresses in this region of the ceramic component are greatest during the operation. These flaws may be intrinsic to the bulk material or can be introduced in the final stages of fabrication (e.g. machining, grinding and polishing). Additionally, in composite ceramics defects can appear as a delamination of internal layers. Because the potential market for ceramic components is so large, a considerable effort has been put into developing non-destructive evaluation (NDE) techniques to detect flaws at various stages of the manufacturing process [1–5]

Cold atom confinement in an all-optical dark ring trap

We demonstrate confinement of $^{85}$Rb atoms in a dark, toroidal optical trap. We use a spatial light modulator to convert a single blue-detuned Gaussian laser beam to a superposition of Laguerre-Gaussian modes that forms a ring-shaped intensity null bounded harmonically in all directions. We measure a 1/e spin-relaxation lifetime of ~1.5 seconds for a trap detuning of 4.0 nm. For smaller detunings, a time-dependent relaxation rate is observed. We use these relaxation rate measurements and imaging diagnostics to optimize trap alignment in a programmable manner with the modulator. The results are compared with numerical simulations.Comment: 5 pages, 4 figure

Phase Modulation at 125 kHz in a Michelson Interferometer Using an Inexpensive Piezoelectric Stack Driven at Resonance

Fast phase modulation has been achieved in a Michelson interferometer by attaching a lightweight reference mirror to a piezoelectric stack and driving the stack at a resonance frequency of about 125 kHz. The electrical behavior of the piezo stack and the mechanical properties of the piezo-mirror arrangement are described. A displacement amplitude at resonance of about 350 nm was achieved using a standard function generator. Phase drift in the interferometer and piezo wobble were readily circumvented. This approach to phase modulation is less expensive by a factor of roughly 50 than one based on an electro-optic effect

Depth-Resolved Subsurface Defect Detection in Ceramics Using Optical Gating Techniques

Components made from advanced ceramics materials find widespread use in many industrial and military applications. However, the presence of defects in the bulk and on the surface of the ceramic parts can alter their operation and lead to a reduced lifetime or a catastrophic failure. These defects may include various inclusions, inherent powder defects, poorly distributed second phase material, as well as voids and cracks. They can be introduced at each stage of the manufacturing process. Near-surface defects are particularly critical in many applications since the stresses in this region of the ceramic component are greatest during the operation. These flaws may be intrinsic to the bulk material or can be introduced in the final stages of fabrication (e.g. machining, grinding and polishing). Additionally, in composite ceramics defects can appear as a delamination of internal layers. Because the potential market for ceramic components is so large, a considerable effort has been put into developing non-destructive evaluation (NDE) techniques to detect flaws at various stages of the manufacturing process [1–5].</p

¿Es la Buprenorfina una buena opción en el manejo de dolor postoperatorio?

Background: Pain is one of the most feared outcomes of surgery by patients, yet current practices of pain management are suboptimal. Failure to address acute postoperative pain can have a variety of consequences that affect physical and psychological aspects of the patient. Current perioperative pain management normally consists of opioid therapy, which has been a mainstay for many years. However, use of opioids can have moderate risks, including nausea/vomiting, dizziness, and constipation, or more severe risks, including respiratory depression and immunosupression. Aim: In order to address some of the issues surrounding perioperative pain management, a group of key opinion leaders gathered at an international summit to analyze the current practices of perioperative pain management. One of the topics focused on buprenorphine's role in perioperative pain and the information discussed is presented throughout this article. Conclusion: Buprenorphine has been demonstrated to be effective and safe in many postoperative pain models. Its administration versatility, its manageable side effects, and its use in combination with other analgesics allow buprenorphine therapy to be successful in perioperative pain management.Antecedentes: El dolor es uno de los eventos más temidos por los pacientes después de una cirugía, y en la actualidad el manejo del dolor es subóptimo. La falta de control del dolor agudo postoperatorio puede tener una serie de consecuencias que afectan a los aspectos físicos y emocionales de los pacientes. El manejo habitual del dolor postoperatorio se basa en la utilización de opioides, pilar de tratamiento desde hace muchos años. Sin embargo, el uso de opioides puede tener riesgos moderados, como son las náuseas y vómitos, mareos y constipación, o riesgos más severos que incluyen a la inmunosupresión y depresión respiratoria. Objetivo: Para poder determinar algunos de los factores circundantes del dolor postoperatorio, se realizó una reunión cumbre internacional en la que un grupo de líderes de opinión analizó las prácticas habituales de manejo de dolor postoperatorio. Uno de los temas abordados fue el rol de la buprenorfina en el manejo del dolor perioperatorio, y la información discutida se presenta a lo largo de este artículo. Conclusión: La buprenorfina ha demostrado ser eficaz y segura en muchos modelos de dolor postoperatorio. Su versatilidad de administración, sus efectos secundarios manejables y su posibilidad de ser combinada con otros analgésicos hacen que la buprenorfina sea exitosa en el manejo del dolor perioperatorio