Mode-resolved Fabry-Perot experiment in low-loss Bragg-reflection waveguides.

Based on the interaction between different spatial modes, semiconductor Bragg-reflection waveguides (BRWs) provide a highly functional platform for non-linear optics. For achieving any desired quantum optical functionality, we must control and engineer the properties of each spatial mode. To reach this purpose we extend the Fabry-Perot technique and achieve a detailed linear optical characterization of dispersive multimode semiconductor waveguides. With this efficient broadband spectral method we gain direct experimental access to the relevant modes of our BRWs and determine their group velocities. Furthermore, we show that our waveguides have lower than expected loss coefficients. This renders them suitable for integrated quantum optics applications.

Dynamic superlubricity on insulating and conductive surfaces in ultra-high vacuum and ambient environment.

Atomic-scale friction between a sharp tip at the end of a micro-fabricated silicon cantilever and atomically flat surfaces (NaCl, KBr, HOPG and mica) can be significantly reduced by piezo-induced perpendicular mechanical oscillations at specific resonance frequencies of the cantilever in gentle contact with the sample. The reported measurements confirm and extend the applicability of the effect recently demonstrated using electro-capacitive actuation on alkali halide surfaces in ultra-high vacuum (Socoliuc et al 2006 Science 313 208). A controlled reduction of friction is now observed even on a conductive surface and under ambient conditions, which is quite promising for applications to micro-electromechanical devices. The theory previously used to interpret 'dynamic superlubricity' is supported by new measurements showing that the contact can be maintained in that regime and that the initial reduction of friction is linear versus oscillation amplitude. The calibration of the oscillating component of the normal force is also discussed.

Full-disclosure monitoring: a concept that will change the way arrhythmias are detected and interpreted in the hospitalized patient.

Conventional methods of detecting and documenting arrhythmia in the hospitalized patient are inadequate. A system of full-disclosure monitoring has been expanded from its roots in Holter monitoring to real-time telemetry. This archiving system stores 24 hours of electrocardiogram (ECG) tracing per patient in computer memory and prints 60 minutes (one minute per line, 60 lines per page) of ECG hourly. This technique eliminates the fear of missing ventricular tachycardia, heart block, or automatic implantable cardioverter defibrillator discharges and ensures that onsets and terminations of runs are captured. Documentation is facilitated by the use of a laser printer that makes standard-sized tracings. The retrospective capability of full disclosure monitoring aids in correlating symptoms to ECG changes and serves as a tool for quality control, bed utilization, and research.