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Related papers: Reduced lasing thresholds in GeSn microdisk caviti…

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GeSn is a promising group-IV semiconductor material for on-chip Si photonics devices and high-mobility transistors. These devices require the use of doped GeSn regions, achieved preferably in-situ during epitaxy. From the electronic valence…

Materials Science · Physics 2023-07-18 Andrea Giunto , Louise Emma Webb , Thomas Hagger , Anna Fontcuberta i Morral

We report on a laser locked to a silicon cavity operating continuously at 4 K with $1 \times 10^{-16}$ instability and a median linewidth of 17 mHz at 1542 nm. This is a ten-fold improvement in short-term instability, and a $10^4$…

Group II-IV nitrides have recently emerged as a novel class of semiconductors composed of earth-abundant elements. Owing to their tunable bandgaps, comparable to those of III-nitrides, these materials are attractive candidates for replacing…

The novel combination of a strongly-resonant optical metasurface with the MoS$_2$/WSe$_2$ hetero-bilayer is proposed for efficient free-space lasing enabled by the enhanced coupling between the optical and matter (exciton) states. The…

We present an absorption line analysis of the Lyman limit system (LLS) at z=3.55 in our Magellan/MIKE spectrum of PKS2000-330. Our analysis of the Lyman limit and full HI Lyman series constrains the total HI column density of the LLS (N_HI…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Gabriel E. Prochter , J. Xavier Prochaska , John M. O'Meara , Scott Burles , Rebecca A. Bernstein

We report new limits on the Gunn-Peterson effect at a redshift near 5 using spectroscopic observations of the z = 5 Sloan Digital Sky Survey quasar, J033829.31+002156.3, made with the LRIS and HIRES spectrographs on the Keck telescopes.…

Astrophysics · Physics 2009-10-31 Antoinette Songaila , Esther M. Hu , Lennox L. Cowie , Richard G. McMahon

Supercontinuum generation (SCG) is an important nonlinear optical process enabling broadband light sources for many applications, for which silicon nitride(Si3N4) has emerged as a leading on-chip platform.To achieve suitable group velocity…

Laser micro-welding is an advanced manufacturing method today applied in various domains. However, important physical limitations have prevented so far to demonstrate its applicability in silicon and other technology-essential…

Applied Physics · Physics 2022-03-31 Pol Sopeña , Andong Wang , Alexandros Mouskeftaras , David Grojo

The thermodynamic stability of germanium tin $\mathrm{Ge_{1-x}Sn_x}$ alloys is investigated across the composition range $0 \le x \le 1$ by applying density functional theory (DFT) together with the cluster expansion formalism (CE). It is…

Materials Science · Physics 2021-03-02 Alfonso Sanchez-Soares , Conor O'Donnell , James C. Greer

Ultraviolet nanosecond laser annealing (LA) is a powerful tool where strongly confined heating and melting are desirable. In semiconductor technologies the importance of LA increases with the increasing complexity of the proposed…

Lithium tetraborate (LB4) is a lithium borate compound and recently has shown renewed interest due to its exceptional linear and nonlinear optical properties. Its wide transparency range, spanning from 0.16$\mu m$ to 3.5$\mu m$, and low…

Validating material performance in electrical devices is crucial to product development. For Gallium Nitride (GaN) devices, evaluating material factors such as defects, dopant concentration, and overall production quality is essential to…

GeSn epitaxial heterostructures are emerging as prominent candidates for the monolithic integration of light sources on Si substrates. Here we propose a judicious explanation for their temperature-dependent photoluminescence (PL) that is…

Materials Science · Physics 2017-10-03 Fabio Pezzoli , Anna Giorgioni , David Patchett , Maksym Myronov

A new kind of mechanism of lasing is investigated experimentally. It is quite different from the traditional laser with cavity and the random laser with random scattering. In this mechanism, the intensity-dependent refractive index effect…

Optics · Physics 2013-06-28 Jinwei Shi , Shujing Chen , Wenjun Fan , Xiangyu Kong , Dahe Liu , Lily Zu

The threshold current density of narrow (1.5 {\mu}m) ridge-waveguide InGaN multi-quantum-well laser diodes, as well as the shape of their lateral far-field patterns, strongly depend on the etch depth of the ridge waveguide. Both effects can…

Rocksalt ScN is a semiconductor with a small lattice mismatch to wurtzite GaN. Within the modern theory of polarization, ScN has a nonvanishing formal polarization along the [111] direction. As a result, we demonstrate that an interface…

Materials Science · Physics 2019-12-23 Nicholas L. Adamski , Cyrus E. Dreyer , Chris G. Van de Walle

Germanium is a strong candidate as a laser source for silicon photonics. It is widely accepted that the band structure of germanium can be altered by tensile strain so as to reduce the energy difference between its direct and indirect band…

An accurate knowledge of the optical constants (refractive index $n$ and extinction coefficient $k$) of ScN is crucial for understanding the optical properties of this binary nitride semiconductor as well as for its use in optoelectronic…

Materials Science · Physics 2023-06-19 Duc V. Dinh , Frank Peiris , Jonas Lähnemann , Oliver Brandt

Superradiant lasers operate in the bad-cavity regime, where the phase coherence is stored in the spin state of an atomic medium rather than in the intracavity electric field. Such lasers use collective effects to sustain lasing and could…

Low-threshold lasing under pulsed optical pumping is demonstrated at room temperature for III-nitride microdisks with InGaN/GaN quantum wells on Si in the blue spectral range. Thresholds in the range of 18 kW/cm2 have been achieved along…