Population inversion in an optically-pumped single quantum well

Population inversion in optically pumped asymmetric quantum well terahertz lasers

Theoretical studies of subband carrier lifetimes in an optically pumped 3-level terahertz laser

Non-radiative (phonon scattering) lifetimes are calculated for asymmetric quantum well structures in the AlGaAs/GaAs materials system. Structures are designed in a 3-level optically pumped laser configuration, and tuned for emission in the terahertz frequency range. For emission frequencies below 8.7THz, the energy gap of the lasing levels is less than the LO phonon energy in GaAs, which leads ...

High Sample Rate Optically Pumped Helium Magnetometer

Optically pumped helium magnetometers are important instruments whichhave many applications in military, mass spectroscopy and space applications. In thispaper, the working principles of helium magnetometers have been explained. There isalso an introduction of a new method for finding the resonant frequency, which hasadvantages to the typical method such as more sample r...

LASERS WITHOUT INVERSION: DENSITY OPERATOR METHOD

A quantum theory of a two and three-level laser with injected atomic coherence is developed by using a density operator method, to the best of our knowledge, for the first time. The initial atomic coherence plays an essential role. At steady state, the equation of motion for the density operator yields to exhibit laser without inversion and a phase locking but no threshold for the laser fie...

Radiative recombination rate measurement by the optically pumped variable stripe length method.

Using the optically pumped variable stripe length technique we demonstrate that, through calibration of measured spontaneous emission spectra, it is possible to determine the total radiative recombination rate for a gain material as a function of the intrinsic quasi-Fermi level separation. Specifically we compare the room temperature optical characteristics of a self-assembled InP/GaInP quantum...