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The characterization of the performance of Fabry-Pérot lasers based on measurements of the amplified spontaneous emission (ASE) spectrum and analysis using the Fourier series expansion method is presented in this paper. We explain how all the parameters of net modal gain, internal loss, quasi-Fermi level separation, linewidth enhancement factor, injection efficiency, and geometric spontaneous emis...Show More
We develop a light-emitting device employing colloidal quantum dots, which exhibits stimulated emission under electrical injection. The device is combined with a Bragg-reflection waveguide structure for a great optical gain and loss balance, leading to ultrabright edge emission due to development of stimulated emission processes.Show More
We investigate the quantum-optical interplay of two-dimensional (2D) planar photonic crystals with localized emitters. Due to the spatial variation of the photonic density of states in the photonic crystal unit cell the spontaneous emission properties dependent strongly on the location of the emitter. We infiltrate nanospheres doped with small dye molecules as localized probes into 2D hexagonal Nb...Show More
The Purcell effect strongly affects the emission in laser nanocavities. We investigate its role in the gain and spontaneous emission rate of nanopillar lasers over a wide range of cavity dimensions and emitter/cavity relative linewidths enabling the modeling of either nano-, meso- or macro-scale lasers.Show More
In this work, a nitride based strained single quantum well laser has been designed and characterized at 1330 nm wavelength. Here, InN has been used as well material and InGaN has been used as barrier material along with GaN as separate confinement heterostructure for better carrier and optical confinement. For the analysis of characteristics of the laser system, 6-bands k.p formalism for wurtzite ...Show More
Comprehensive Fabry-Pérot laser characterization based on measurements of the amplified spontaneous emission spectrum analyzed using the Fourier series expansion method is presented. The parameters of net modal gain, internal loss, quasi-Fermi level separation, linewidth enhancement factor, injection efficiency, and geometric spontaneous emission factor can all be extracted.Show More
In this paper, an innovative incoherent light source, based on the amplified spontaneous emission (ASE) phenomenon, is proposed. It is pumped at 980 nm and is based on a Tm:Er:Yb:Ho co-doped germanate glass fiber. The simulation predicts multi-wavelength emission peaks in a bandwidth of over 543 nm, in the wavelength range 1500-2100 nm. A numerical home-made solver, based on a nonlinear rate equat...Show More
We demonstrated a significant reduction of amplified spontaneous emission (ASE) threshold for an organic optical gain medium operation on an ITO-coated glass by introducing a solution-processed cellulose acetate (CA) thin film as a space layer between the ITO electrode and the optical gain active layer. Using PFO as an optical gain medium, we observed a 4.4-fold threshold reduction from 140 μJ/cm2...Show More
The net modal gain and the un-amplified spontaneous emission (ASE) coupled into the laser waveguide mode are extracted from the ASE spectrum of Fabry-Perot semiconductor lasers by the Fourier transform method with a deconvolution process. Highly accurate quasi-Fermi level separation and internal loss are then derived by a minimum search process from the relationship between the spontaneous emissio...Show More
We show that conventional expressions for spontaneous emission into waveguide modes correctly predict broadband (non-resonant) Purcell enhancement in slot waveguides. Time resolved photoluminescence measurements on Er-doped ultra-thin 8.3 nm slot channel waveguides corroborate this effect.Show More
We report a study on the effect of spontaneous emission noise present in pulsed probe radiation on the reflectogram shape deformation in a distributed temperature sensor based on Raman scattering of light. Since the fraction of spontaneous emission in the used erbium-doped amplifier can reach 50% of the total power, its influence leads to deviations of reflectograms in the temperature sensor from ...Show More
Externally amplified spontaneous emission (ASE) injection-locking characteristics and optical data transmission performances of a TO-56 can-packaged Fabry-Perot laser diode (FPLD) with 1% front-facet reflectivity are investigated using a wavelength-division-multiplexing passive-optical network (WDM-PON) system configured by an array-waveguide grating (AWG) based MUX/DMUX filters with channel spaci...Show More
We present a self-consistent electric and optic model for superluminescent light-emitting diodes (SLED) using 3D finite-element method. The carrier transport is calculated by the drift-diffusion method, which is coupled with the radiative recombination obtained from the solution of Shrodinger-Poison equations self-consistently. The spontaneous emission noise is described by the fundamental theory ...Show More
The threat and defend model of optical steganography based on amplified spontaneous emission noise is experimentally demonstrated. Although the optical delays in a steganography system generate large key space to hide and recover the stealth signals, delays in interferometer introduce spectral fringes that can be identified by the coherent detection attack and thus expose the stealth channel. To d...Show More
Amplified spontaneous emission (ASE) occurs in media with large gain, and affects both the magnitude and the spatial distribution of the inversion. In this work we theoretically study the effect of ASE in three-dimensional, rectangular slab amplifiers, using Monte Carlo type computer simulations. We found that in one-dimensional amplifiers ASE is always larger at the edges so that the inversion ha...Show More
We investigate the effect of ASE on the gain modulation, referred to also as overmodulation. The gain modulation is the low-frequency ( kHz) amplitude modulation of the EDFA pump and the communication signal used for propagating line monitoring information. We develop the model of Novak and Moesle (2002), by including amplified spontaneous emission (ASE), that they neglected it. The derivation of ...Show More
In this paper, we discuss main issues concerning light amplification in Erbium-doped fiber amplifiers. We investigate the impact of propagation delay through Erbium-fiber; influence of stochastic adding and dropping of wavelength division multiplexing on the gain of EDFAs; and, finally, we explain the amplified spontaneous emission of ions, which is an optical noise in EDFAs. Using backward ASE as...Show More
A new technique for the measurement of net modal gain spectra of semiconductor lasers is presented. The technique is based on a least squares curve fitting to each longitudinal mode of amplified spontaneous emission spectrum. The errors of measurement over a wide wavelength range because of the asymmetric shape of individual mode and the limit resolution of the optical spectrum analyzer are greatl...Show More
We propose a scheme to modify spontaneous emission spectra with split rings. We consider the heterogeneous environment around the dipole and the dipole as a whole to comprehensively explore the impact of the parameters of the system on the partial local density of state. And we achieve the customization of spontaneous emission spectra by engineering the partial local density of state with the co-d...Show More
We numerically analyze the modified spontaneous emission from an electric dipole located inside microcavities created in a two-dimensional photonic crystal. Three-dimensional finite-difference time-domain (FDTD) calculations show about 300 times enhancement of the vertical spontaneous emission of a dipole inside a microstructure. The dependence of the spontaneous emission on dipole position is stu...Show More
The laser linewidth manifests the spectral coherence of a lasing resonator mode. It is of fundamental importance, theoretically as much as practically. For more than half a century we have been told that the laser linewidth is a result of quantum fluctuations due to spontaneous emission, which induce amplitude and phase fluctuations, whereas stimulated emission occurs in phase with the incident fi...Show More
The processes of absorption and stimulated emission are investigated via (i) energy conservation in a Fabry-Perot resonator, (ii) the Lorentz-oscillator model, and (iii) the Kramers-Kronig relations. Vacuum fluctuations are added and the relation between stimulated and spontaneous emission is clarified. It is shown that previous models start from incorrect assumptions about the physical foundation...Show More
An amplified spontaneous emission model for quantum-well (QW) distributed feedback (DFB) lasers is presented, which takes into account local spontaneous emission, stimulated emission, and real refractive index change which are calculated from the Fermi-Dirac occupancy functions in a self-consistent manner. The local-normal-mode transfer-matrix method is used, which allows a coupling of the local D...Show More
We present a theoretical investigation of the spectral properties of spontaneous emission in semiconductor optical amplifiers. We use an extended (3/spl times/3) transfer matrix formalism to derive in the spectral domain an expression for the total longitudinally averaged internal field, which is valid regardless of the levels of optical input and bias current. The material parameters are saturate...Show More