Showing 3 results for Spontaneous Emission
E. Karimzadeh Esfahani, M. Bagheri Harouni, R. Roknizadeh,
Volume 3, Issue 1 (3-2009)
Abstract
In this paper we consider electromagnetic field quantization in the presence of a dispersive and absorbing semiconductor quantum dot. By using macroscopic approach and Green's function method, quantization of electromagnetic field is investigated. Interaction of a two-level atom , which is doped in a semiconductor quantum dot, with the quantized field is considered and its spontaneous emission rate is calculated. Comparing with the same condition for an excited atom inside the bulk, it is shown that the spontaneous emission rate of an atom will decrease.
G. Sreelekha, G. Vidya, K. Geetha, R. Joseph, S. Prathapan, P. Radhakrishnan, C.p.g. Vallabhan, V.p.n. Nampoori,
Volume 5, Issue 1 (1-2011)
Abstract
We report the observations of dual wavelength amplified spontaneous emission from the solutions of a conjugated polymer poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) in Tetrahydrofuran and 1, 2 Dichlorobenzene. We have prepared MEH-PPV using a modified procedure and purified several times in each step, the material offers low molecular weight, low polydispersity index and high thermal stability, which are some of the most important requirements for the fabrication of photo luminescent devices. The variation in the features of amplified spontaneous emission with increasing polymer concentration is presented. For intermediate polymer concentrations, narrow emissions were observed for the 0-0 and 0-1 vibronic peaks which were not reported in solutions to the best of our knowledge. The ASE characteristics sensitively depend on concentration as well as pump power. The gain studies show that MEH-PPV is a potential laser media. By varying the concentration of the solution and pump power we can use either of the two different wavelength bands for lasing applications.
Mozhgan Mahdizadeh Rokhi, Asghar Asgari,
Volume 16, Issue 1 (1-2022)
Abstract
In this article, the temperature behavior of output power of superluminescent light-emitting diode (SLED) by considering the effect of non-radiative recombination coefficient, non-radiative spontaneous emission coefficient and Auger recombination coefficients has been investigated. For this aim, GaN pyramidal quantum dots were used as the active region. The numerical method has been used to solve three-dimensional Schrodinger equations and traveling-wave equations. The spectral width of the gain spectrum in each case has been investigated. Eliminating the non-radiative recombination, non-radiative spontaneous emission coefficient and Auger recombination coefficients increased the output power of SLED and in some cases reduced the negative effect of temperature increase on output power.
