Related Articles Mid-infrared-pumped, electrically driven terahertz quantum laser: Enhanced pumping efficiency and prevention of electric-field domains J. Appl. Phys. 113, 033103 (2013) How does external feedback cause AlGaAs-based diode lasers to degrade? Appl. Phys. Lett. 102, 023502 (2013) Large-area ultraviolet GaN-based photonic quasicrystal laser with high-efficiency green color emission ...

The impact of upper state lifetime and spatial hole burning on pulse shape and stability in actively mode locked QCLs is investigated by numerical simulations. It is shown that an extended upper state lifetime is necessary to achieve stable isolated pulse formation per roundtrip. Spatial hole burning helps to reduce the pulse duration by supporting broadband multimode lasing, but introduces pul...

LLE Review, Volume 90 79 Solid-state laser systems envisioned for inertial fusion energy (IFE) applications will require both high efficiency and high single-beam, on-target uniformity. High efficiency is achieved by diode pumping, and on-target uniformity is achieved by beam-smoothing techniques. One of the most-promising gain media for these high-efficiency lasers is ytterbium-doped strontium...

Laser action of the photo-thermo-refractive (PTR) glass, which is the photosensitive material for holographic recording of volume Bragg gratings (VBGs), was demonstrated for the first time by introducing Nd³⁺. Nd:PTR glass has a bandwidth of 27.8 nm and 16.0 nm for luminescence and absorption, respectively. An uncoated 2 mm thick Nd:PTR element generated cw laser output of 124 mW, with a slope ...

Band-edge liquid crystal lasers are of interest for a number of applications including laser projection displays. Herein, we demonstrate simultaneous red-green-blue lasing from a single liquid crystal sample by creating a two-dimensional laser array fabricated from dye-doped chiral nematic liquid crystals. By forming a pitch gradient across the cell, and optically pumping the sample using a len...

A multimode model of a continuously pumped atom laser is shown to be unstable below a critical value of the scattering length. Above the critical scattering length, the atom laser reaches a steady state, the stability of which increases with pumping. Below this limit the laser does not reach a steady state. This instability results from the competition between gain and loss for the excited stat...

A solid-state laser based on a dye-doped deoxyribonucleic acid (DNA) matrix is described. A thin solid film of DNA has been fabricated by treating with polyvinyl alcohol (PVA) and used as a host for the laser dye Rhodamine 6G. The edge emitted spectrum clearly indicated the existence of laser modes and amplified spontaneous emission. Lasing was obtained by pumping with a frequency-doubled Nd:YA...

A seven-rod solar laser head was conceptualized and numerically studied to improve the tracking error compensation capacity power stability in end-side-pumping schemes. It composed of a first-stage heliostat–parabolic mirror system, second-stage fused silica aspheric lens third-stage conical pumping cavity, within which seven Nd:YAG rods were mounted. Highly stable emission, with loss inferior ...

BACKGROUND The nematode Caenorhabditis elegans is widely used for studying small neural circuits underlying behavior. In particular, the rhythmic feeding motions collectively termed pharyngeal pumping are regulated by a nearly autonomous network of 20 neurons of 14 types. Despite much progress achieved through laser ablation, genetics, electrophysiology, and optogenetics, key questions regardin...

An electrically pumped ZnO homojunction random laser diode based on nitrogen-doped p-type ZnO nanowires is reported. Nitrogen-doped ZnO nanowires are grown on a ZnO thin fi lm on a silicon substrate by chemical vapor deposition without using any metal catalyst. The p-type behavior is studied by output characteristics and transfer characteristic of the nanowire back-gated fi eld-effect transisto...