We discuss mode-locking of low-gain solid-state lasers using a semiconductor saturable Bragg reflector structure. This recently developed low-loss mode-locking device consists of a single quantum well which acts as a saturable absorber incorporated into a high-reflectivity Bragg mirror. Highly stable mode-locking in solid-state lasers results from an ultrafast transient reflectivity in the devi...

We demonstrate self-starting passive mode locking of a Cr (4+):YAG laser, using an intracavity nonlinear mirror as a saturable absorber. The pump source is a diode-pumped Nd:YVO(4) laser. Output pulses are centered at 1541 nm, with 26-nm spectral bandwidth and 110-fs pulse width. Output powers of 70 mW are obtained with 8 W of pump power. This mode locking technique is compared with Kerr-lens m...

We prove the nonexistence of nonconstant local minimizers for a class of functionals, which typically appear in scalar two-phase field models, over smooth N -dimensional Riemannian manifolds without boundary and nonnegative Ricci curvature. Conversely, for a class of surfaces possessing a simple closed geodesic along which the Gauss curvature is negative, we prove the existence of nonconstant l...

|A voltage controlled di erential injection locked frequency divider (VCDILFD) with a large locking range is designed in a 0:24 m CMOS technology. A 29% locking range is achieved by an optimal inductor design and also by employing high Q accumulation mode MOS varactors to change the free{running oscillation frequency of the divider. The measurement results show frequency division at 5GHz with m...

Locking rules for concurrency control in nested transaction model, in which parent/child parallelism, sibling parallelism, and arbitrary commitment-dependence relationship between transactions are allowed, are presented. The locking rules are based on the lock transformation scheme that never allows the commit deadlock to occur, which could happen by permitting parent/child parallelism. In addi...

We report the discovery of a codimension-two phenomenon in phase diagram second-order self-sustained nonlinear oscillator subject to constant external periodic forcing, around which three regimes associated with synchronization exist, namely phase-locking, frequency-locking without and frequency-unlocking states. The triple point arises when saddle-node homoclinic cycle collides zero-amplitude ...

PURPOSE This meta-analysis compared the clinical outcomes of locking plate with intramedullary nail in the treatment of displaced proximal humeral fractures. METHODS We searched PubMed, Embase, and the Cochrane databases for studies comparing locking plate and intramedullary nail treatment of displaced two-, three-, or four-part proximal humeral fractures. The quality of the studies was asses...

PURPOSE The objective of this study was to assess the biomechanical properties of bicortical locking screws, unicortical locking screws, and unicortical far-cortex-abutting locking screw fixation in a cadaver model of comminuted midshaft clavicle fractures stabilized with a locking plate placed on the superior surface of the clavicle. METHODS Nine pairs of adult fresh-frozen cadaver clavicles...

Modulation of a cw laser by a traveling-wave acousto-optic modulator has recently been utilized to implement sequences of phase-coherent optical pulses.' By controlling the relative phases of the rf pulses applied to the crystal, one can control the phases of the light pulses that are created by the acoustic grating. That is, the phase of an rf pulse is effectively transferred to the correspond...

We present a simple and automatic method for determining the uncertainty in the retrieved intensity and phase versus time (and frequency) due to noise in a frequency-resolved optical-gating trace, independent of noise source. It uses the ‘‘bootstrap’’ statistical method and also yields an automated method for phase blanking (omitting the phase when the intensity is too low to determine it). © 2...