Optically pumped terahertz laser based on intersubband transitions in a GaN∕AlGaN double quantum well

Quantum Well Intersubband Transitions as a Source of Terahertz Radiation

| It is shown that unipolar quantum well systems have potential as sources of terahertz radiation. It is demonstrated that the electronic interactions within these systems must be manipulated in order to favour radiative emission rather than non-radiative loss. Designs are advanced for tunable emitters and optically excited terahertz lasers.

Population inversion in optically pumped asymmetric quantum well terahertz lasers

Terahertz Lasers Based on Intersubband Transitions

Semiconductor quantum wells are human-made quantum mechanical systems in which the energy levels can be designed and engineered to be of any value. Consequently, unipolar lasers based on intersubband transitions (electrons that make lasing transitions between subband levels within the conduction band) were proposed for long-wavelength sources as early as the 1970s. However, because of the great...

Terahertz quantum cascade lasers based on intra-well optical transitions

The possibility to achieve laser action at different THz frequencies employing the so-called vertical transition will be discussed. The intra-well or vertical optical transition presents a number of features that makes it an ideal candidate for a systematic study of resonant tunnelling and dephasing in quantum cascade lasers. Laser action at 3.5 THz with very low threshold employing a single qu...

Optically pumped laser characteristics of blue Znx8Cdy8Mg1Àx8Ày8SeÕZnxCdyMg1ÀxÀySe single quantum well lasers grown on InP

We report the operation of a photopumped blue Znx8Cdy8Mg12x82y8Se/ZnxCdyMg12x2ySe separate confinement heterostructure single quantum well laser grown lattice matched to InP with a relatively thick quaternary quantum well ~;50 Å!. Laser emission at 492 nm in the blue was observed. The lasing linewidth is about 5 nm. Based on the temperature dependency of the threshold pumping intensity, the cha...