GaAs/GaAlAs heterostructure lasers with a monolithic confocal unstable resonator were demonstrated. The curved mirrors satisfying the confocal condition were fabricated by etching. Close to threshold, the lasers operate in a single lateral mode with a nearly collimated output beam. A single-lobe far-field intensity distribution as narrow as 1.9 degrees full width at half maximum was measured.

A compact side-pumped solar laser design using a Ce:Nd:YAG medium is here proposed to improve the TEM00-mode output performance, more specifically beam brightness. The performance of head was numerically studied by both ZEMAX® v13 and LASCADTM v1 software. Maximum multimode power 99.5 W computed for 4.1 mm diameter, 34 length grooved rod, corresponding collection efficiency 33.2 W/m2. To extrac...

The three-dimensional propagation of electromagnetic waves in a distributed Schottky barrier transmission line is investigated. In one case, we show that the electromagnetic fields are similar to those that were originally obtained by Goubau and Schwering in their development of the beam waveguide. This case can lead to a very low-loss distributed Schottky barrier resonator.

In a simple picture, a Bessel beam is viewed as a transverse standing wave formed in the interference region between incoming and outgoing conical waves. Based on this interpretation we propose an optical resonator that supports modes that are approximations to Bessel-Gauss beams. The Fox-Li algorithm in two transverse dimensions is applied to confirm the conlcusion.

We investigate the ray dynamics in an optical cavity when a ray-splitting mechanism is present. The cavity is a conventional two-mirror stable resonator, and the ray splitting is achieved by inserting an optical beam splitter perpendicular to the cavity axis. Using Hamiltonian optics, we show that such a simple device presents surprisingly rich chaotic ray dynamics.

A theory for oscillation in an optical resonator with photorefractive gain was formulated. The threshold conditions for the oscillation were also obtained. The result, applicable to a whole class of new devices, is a prediction for an oscillation frequency different from that of the pump beam.

Although it is challenging to implement follower forces in macroscale laboratory experiments, they can be implemented fairly easily in MEMS devices. This paper discusses the implementation of follower and axial end forces in a beam-type MEMS resonator for the application of resonant frequency tuning. r 2005 Elsevier Ltd. All rights reserved.

We have demonstrated that a hybrid laser array, combining graded-photonic-heterostructure terahertz semiconductor lasers with a ring resonator, allows the relative phase (either symmetric or anti-symmetric) between the sources to be fixed by design. We have successfully phase-locked up to five separate lasers. Compared with a single device, we achieved a clear narrowing of the output beam profile.

Nanomechanical resonators with fundamental mode resonance frequencies in the very-high frequency (VHF), ultra-high frequency (UHF) and microwave L-band ranges are fabricated from monocystalline silicon carbide (SiC) thin film material, and measured by magnetomotive transduction, combined with a balanced-bridge readout circuit. For resonators made from the same film, we measured the frequency de...