Investigation On The Decay Coherent In Semiconductor Quantum Wells And The Influences To Group Velocity Dispersion

When atoms spontaneous emission jump from two adjacent state energy levels to the same ground state, or from the same excited state level to two adjacent ground states, cross coupling will occur between the two spontaneous emission channels under certain conditions, generating an interference effect. This interference effect result from spontaneous emission, it was known as the Spontaneously Generated Coherence, also known as the vacuum induced coherence, relaxation induced coherence, or decay-induced coherence, also namely the decay-coherence.SGC is a kind of coherence generated by Spontaneous emission. There are many peculiar physical phenomena related to SGC just for SGC can modify the process of the interaction between electromagnetic fields and atom, including transparency of a short laser pulse, lasing without inversion, coherent population trap and transfer, electromagnetically induced transparency, coherent hole burning, double dark states, photon correlation, control of group velocity, enhanced Kerr nonlinearity, phase control of gain and absorption, cancellation and quenching of spontaneous emission, narrowing and squeezing of fluorescence, phase sensitive spectra of spontaneous emission.According the application in the semiconductor quantum well decay coherent effects,We can control and manipulate the asymmetric coupled quantum well semiconductor medium on the physical absorption and dispersion properties of the field and the change of the group velocity.At the same time on the coupling of the semiconductor quantum well through the coherent effect to regulate and control the optical bistable and steady-state behavior.These are all significant research subject and direction in the semiconductor quantum well decay coherent research, they are significance in theory and application.In summary, the study of SGC and those special effects related to SGC not only gives insight of the basic quantum dynamics and will be helpful to deepen understanding of the process of the interaction between electromagnetic fields and atom, and then improve quantum system characteristics of optical material, but also promotes us to improve their potential applications value of actual application technologies.