Effective Green Semiconductor Lasers with Multiple CdSe/ZnSe QD Active Region for Electron Beam Pumping

Abstract

The characteristics of ZnSe-based electron beam pumped semiconductor lasers are presented in detail. The laser structures consist of a 0.6 µm thick superlattice waveguide centered with ten equidistantly placed CdSe/ZnSe quantum dot active layers. The maximum light output pulse power of 12 W per facet at room temperature along with an extremely high quantum efficiency of ≈ 8.5% were obtained at an electron beam pumping energy of 23 keV (the laser wavelength is of 542 nm). The calculations of a spatial distribution of non-equilibrium carrier concentration within the semiconductor structures under electron beam pumping are presented. The possible ways of further improvement of laser efficiency are discussed.

ZnSe‐based laser structures for electron‐beam pumping with graded index waveguide

“…Both demonstrated the similar values of maximum output power. Moreover, the values are comparable with that obtained previously in EBP laser structures with a multiple QW active region and an extended waveguide [2]. No saturation of the output power has been observed.…”

“…4. The lasing wavelength is of ~535 nm at T=290 °C, and the threshold current density is as low as J th =1.2 A/cm 2 at E e =8-12 kV. …”

“…The specific advantages of EBP lasers are the wide-range frequency modulation of the light output power, the electronic control of a directivity diagram, and synchronization of light and pump pulses at a level of a fraction of nanoseconds. During the last decade the extremely low threshold current density (J th =0.4-0.5 A/cm 2 at E e =5-12 kV) and high efficiency ZnSe-based laser structures were grown by molecular beam epitaxy (MBE) [1]. The quantum efficiency of ~8.5% as well as light output power of ~12 W (per facet) have been achieved in laser structure with 0.65-μm-thick superlattice (SL) waveguide and ten ZnSe/CdSe quantum dot (QD) sheets [2].…”

“…During the last decade the extremely low threshold current density (J th =0.4-0.5 A/cm 2 at E e =5-12 kV) and high efficiency ZnSe-based laser structures were grown by molecular beam epitaxy (MBE) [1]. The quantum efficiency of ~8.5% as well as light output power of ~12 W (per facet) have been achieved in laser structure with 0.65-μm-thick superlattice (SL) waveguide and ten ZnSe/CdSe quantum dot (QD) sheets [2]. This paper reports on our recent results on fabrication of II-VI EBP laser heterostructures with graded-index SL waveguide, aimed at improvement of carrier collection in the active region and, hence, lowering the threshold current density at electron beam energies much below 10 kV.…”

Formation of a Colloidal CdSe and ZnSe Quantum Dots via a Gamma Radiolytic Technique

“…The electronic, optical, and magnetic properties of quantum dots can be tailored by changing the material composition and varying the physical size [1][2][3]. In particular, group II-VI compounds such as narrow band gap CdSe quantum dots and wider band gap ZnSe quantum dots, have become intriguing materials prospects for the development of electro-optical, optical, and biomedical devices, such as light-emitting diodes [4], photo detectors [5], lasers [6], solar cells [7], and biomedical imaging applications [8,9].…”