English
Related papers

Related papers: Tailoring Chirp in Spin-Lasers

200 papers

In antenna arrays, wave propagation modeling based on Euclidean principles is typically represented by steering vectors or signals. This paper provides a new, chirp-based, interpretation of steering vectors in the Spherical Wavefront Regime…

Signal Processing · Electrical Eng. & Systems 2025-05-09 Gilles Monnoyer , Laurence Defraigne , Baptiste Sambon , Jérôme Louveaux , Luc Vandendorpe

Nonstationary pulse regimes associated with self modulation of a Kerr-lens modelocked Ti:sapphire laser have been studied experimentally and theoretically. Such laser regimes occur at an intracavity group delay dispersion that is smaller or…

We present a novel laser mode-locking scheme and discuss its unusual properties and feasibility using a theoretical model. A large set of single-frequency continuous-wave lasers oscillate by amplification in spatially separated gain media.…

It has been known for quite some time that spinning polygon, and similar, swept lasers used in OCT favor the short to long wavelength sweep direction because of four wave mixing in the gain medium. Here we have reformulated the problem in…

Laser diodes with optical feedback can exhibit periodic intensity oscillations at or near the relaxation-oscillation frequency. We demonstrate optoelectronic oscillators based on external-cavity semiconductor lasers in a periodic dynamical…

Arrays of 10 nm-diameter point contacts of exchange-coupled spin-majority/spin-minority ferromagnetic metals, integrated into infrared-terahertz range photon resonators, are fabricated and measured electrically and optically. Giant,…

Mesoscale and Nanoscale Physics · Physics 2013-11-27 V. Korenivski , A. Iovan , A. Kadigrobov , R. I. Shekhter

Chirality-induced spin selectivity (CISS) refers to the fact that electrons get spin polarized after passing through organic chiral molecules in a nanoscale device. In CISS, chiral molecules are commonly believed to be a spin filter through…

Mesoscale and Nanoscale Physics · Physics 2022-12-06 Yotam Wolf , Yizhou Liu , Jiewen Xiao , Noejung Park , Binghai Yan

The generation of an out-of-equilibrium population of spin-polarized carriers is a keystone process for quantum technologies and spintronics alike. It can be achieved through the so-called optical spin orientation by exciting the material…

We demonstrate lasing mode selection in nearly circular semiconductor microdisks by shaping the spatial profile of optical pump. Despite of strong mode overlap, adaptive pumping suppresses all lasing modes except the targeted one. Due to…

Optics · Physics 2016-02-18 Seng Fatt Liew , Brandon Redding , Li Ge , Glenn S. Solomon , Hui Cao

We present a simple and direct method for measuring laser chirp rate, i.e., group delay dispersion (GDD) of ultrashort laser pulses at power levels compatible with single-quantum-emitter excitation. Traditional pulse characterization…

We have developed experimental methods for the generation of chirped laser pulses of controlled frequency evolution in the nanosecond pulse length range for coherent atomic interaction studies. The pulses are sliced from the radiation of a…

We propose a semi-analytical method of calculating the timing fluctuations in mode-locked semiconductor lasers and apply it to study the effect of delayed coherent optical feedback on pulse timing jitter in these lasers. The proposed method…

A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field,…

Quantum Physics · Physics 2017-02-22 Matthias M. Dellweg , Carsten Müller

The dependence of the semiconductor laser wavelength on the pump current is a well-known phenomenon, which is generally attributed to a change in the refractive index of the active layer due to carrier injection. This effect is usually…

Multimode lasers have a very complex dynamics, as expected when oscillators are nonlinearly coupled. Order emerges when the modes lock together; in this case the coherent superposition of the modes results into a periodic train of pulses or…

This paper proposes the use of a LoRa like chirp spread spectrum physical layer as the basis for a new Power Line Communication modulation scheme suited for low-bandwidth communication. It is shown that robust communication can be…

Signal Processing · Electrical Eng. & Systems 2021-06-29 Stephen Robson , Abderrahmane Haddad

Effects of nonlinearity in Thomson scattering of a high intensity laser pulse from electrons are analyzed. Analytic expressions for laser pulse shaping in amplitude and frequency are obtained which control spectrum broadening for…

Plasma Physics · Physics 2014-12-09 S. G. Rykovanov , C. G. R. Geddes , C. B. Schroeder , E. Esarey , W. P. Leemans

We provide a theory of laser-induced interaction between spins localized by impurity centers in a semiconductor host. By solving exactly the problem of two localized spins interacting with one itinerant exciton, an analytical expression for…

Other Condensed Matter · Physics 2016-08-31 C. Piermarocchi , G. F. Quinteiro

A standard method to reduce the linewidth of semiconductor lasers involves the use of external optical feedback (EOF). However, feedback powers less than 1 % usually trigger coherence collapse (CC), leading to chaotic laser dynamics and…

We first predict the splitting of a spin degenerate impurity level when this impurity is irradiated by a circularly polarized laser beam tuned in the transparency region of a semiconductor. This splitting, which comes from different…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 M. Combescot , O. Betbeder-Matibet