Abstract
Recently lead salts quantum well lasers which exhibit strong quantum optical effects, have been used to fabricate infrared diode lasers with wide singlemode tunability, low waste heat generation and large spectral coverage up to about 10 µm. Based on the energy dependent effective mass method, a theoretical model was developed to study the effects of band non parabolicty and temperature on the tunability of IVVI PbSe/Pb 0.934 Sr 0.066 Se laser system. This study will show the effects of temperature as a function of well width on the emitted wavelength. Moreover, it will be shown that the effects of non parabolicity on the energy levels can't be ignored in the nano range well width.
Highlights
Mid-IR Quantum Cascade Lasers (QCLs) are fabricated from large band gap GaAs and InP based IIIV semiconductor structures designed to have inter subband transition energies that enable mid-IR photon emission
A second cascade laser approach, pioneered by Yang et al (2005) and replicated at the Naval Research Laboratory (Kim et al, 2007), involves use of narrow band gap GaSb based hetero-structures that employ a type II band alignment. In this case, lasing involves interband transitions between quantum confined conduction and valence subband states such that low energy mid-IR photons are generated. These lasers can benefit from the same cascade effect as QCLs, but since the lasing transitions are interband the subband dispersions for the relevant laser transition states are not parallel and this helps to reduce significantly upper laser transition state depopulation effects associated with electron-phonon scattering
As shown in the figure, the energy levels including the effects of non parabolicity are lower than those excluding the effects of nonparabolicity and this difference is higher for small well width values and decreases as the well width is increased
Summary
Mid-IR Quantum Cascade Lasers (QCLs) are fabricated from large band gap GaAs and InP based IIIV semiconductor structures designed to have inter subband transition energies that enable mid-IR photon emission. A second cascade laser approach, pioneered by Yang et al (2005) and replicated at the Naval Research Laboratory (Kim et al, 2007), involves use of narrow band gap GaSb based hetero-structures that employ a type II band alignment. In this case, lasing involves interband transitions between quantum confined conduction and valence subband states such that low energy mid-IR photons are generated. Interband mid-IR lasers, such as IC and IV-VI diode lasers, have inherent advantages over QCL-type intersubband mid-IR lasers
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Research Journal of Applied Sciences, Engineering and Technology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
