Search results for "Longitudinal mode"
showing 10 items of 13 documents
Coexistence of single-mode and multi-longitudinal mode emission in the ring laser model
2005
A homogeneously broadened unidirectonal ring laser can emit in several longitudinal modes for large enough pump and cavity length because of Rabi splitting induced gain. This is the so called Risken-Nummedal-Graham-Haken (RNGH) instability. We investigate numerically the properties of the multi-mode solution. We show that this solution can coexist with the single-mode one, and its stability domain can extend to pump values smaller than the critical pump of the RNGH instability. Morevoer, we show that the multi-mode solution for large pump values is affected by two different instabilities: a pitchfork bifurcation, which preserves phase-locking, and a Hopf bifurcation, which destroys it.
Longitudinal associations of student–teacher relationships and behavioural and emotional strengths on academic achievement
2017
Positive student–teacher relationships are related to students’ academic achievement and behavioural and emotional adjustment. How a student’s behavioural and emotional strengths are associated with these relationships and how the relationships influence students’ academic performance remains unknown. We examined this framework using a cross-lagged panel model with a group of Finnish students and their parents from Grade 5 to Grade 7. The results revealed that the parents rated behavioural and emotional strengths are stable over a 1-year (r = .78) and 2-year (r = .71) period and that students’ perceptions of student–teacher relationships demonstrated greater change over time (r’s = .54, .35…
Control design for a hypersonic aircraft using a switched linear parameter-varying system approach
2012
This paper is concerned with the control problem of an air-breathing hypersonic aircraft using a switched linear-parameter-varying systems approach. The rigid non-linear longitudinal model of a generic hypersonic aircraft is adopted with the aim of verifying the design methodology of the developed controller and switching logic. By linearizing the non-linear model of the hypersonic aircraft at trim points and dividing the velocity range into several parts, a switched linear parameter-varying model for the underlying system is derived. With the aid of multiple Lyapunov-like functions technique, controllers that ensure the tracking of given commands of the closed-loop system are designed und…
Correlation patterns from massive phonons in 1+1 dimensional acoustic black holes: A toy model
2018
Transverse excitations in analogue black holes induce a mass like term in the longitudinal mode equation. With a simple toy model we show that correlation functions display a rather rich structure characterized by groups of parallel peaks. For the most part the structure is completely different from that found in the massless case.
One- and two-photon lasers with injected signal in a high-Q fabry-Pérot cavity
2000
Explicit models are derived for good cavity one- and two-photon lasers with an injected signal in a Fabry-Perot cavity. The steady solutions and their stability properties are obtained analytically and compared with the corresponding ring cavity model ones. Only quantitative differences between both types of cavities are found. In particular we show that (i) the Fabry-Perot cavity reduces significantly the domain of self-pulsing with respect to the ring cavity, and for the two-photon laser case (ii) larger output can be extracted from a Fabry-Perot cavity than from a ring cavity under certain conditions, something impossible in free-running lasers. We conclude that ring cavity models are se…
Self Calibrating Nano-Ruler
2012
The aim of a nanoruler is to measure distances on a length scale in the order of nanometers. This concept can be realized by two plasmonic nanoparticles (usually spheres), which are placed within a short distance to each other. Since the plasmon modes of both particles are coupled, they influence each other along the interparticle axis (i.e. longitudinal plasmon mode, resulting in a shift of the resonance wavelength compared to the single particle. Because the resulting resonance wavelength depends on the interparticle distance, the spectral investigation of such a dimer allows the determination of the interparticle distance.
Examining bi-directionality between Fear of Missing Out and problematic smartphone use. A two-wave panel study among adolescents.
2020
Abstract Background In recent years, the Fear of Missing Out (FoMO) construct has been the object of growing attention in digital technology research with previous studies finding support for the relationship between FoMO and problematic smartphone use (PSU) among adolescents and young adults. However, no previous studies clarified the causal link between FoMO and PSU using a longitudinal design. Methods An auto-regressive, cross-lagged panel design was tested by using a longitudinal dataset with two waves of data collection (T0 and T1, one year apart). Participants included two hundred and forty-two adolescents (109 males and 133 females), with a mean age of 14.16 years, who filled out the…
Traditional Masculinity and Aggression in Adolescence: Its Relationship with Emotional Processes
2021
Traditional masculinity includes norms that encourage many of the aggressive behaviors whereas traditional femininity emphasizes aggression very little. In addition, the lack of emotional regulation as well as a poor impulse control have been related to aggression and, in particular, with reactive and proactive aggression. The objective of this study is to examine the role of gender stereotypes (masculinity/femininity) in reactive and proactive aggression, through regulatory emotional self-efficacy and emotion regulation. A total of 390 adolescents participated in a longitudinal study in Valencia, Spain. Structural equations modeling (SEM) was employed to explore a two-wave longitudinal mod…
Dissipative structures in optomechanical cavities
2012
Motivated by the increasing interest in the properties of multimode optomechanical devices, here we study a system in which a driven mode of a large-area optical cavity is despersively coupled to a deformable mechanical element. Two different models naturally appear in such scenario, for which we predict the formation of periodic patterns, localized structures (cavity solitons), and domain walls, among other complex nonlinear phenomena. Further, we propose a realistic design based on intracavity membranes where our models can be studied experimentally. Apart from its relevance to the field of nonlinear optics, the results put forward here are a necessary step towards understanding the quant…