A new approach for calculating the ion dose spatial distribution of the focused ion beam is proposed. The approach is based on the analysis of the secondary electron microscopy image of the area irradiated by the focused ion beam.

Subject of study. Distributed-feedback ring-cavity surface-emitting quantum-cascade lasers are studied. Aim of study. The aim is to realize stable single-mode emission in ring-cavity surface-emitting quantum-cascade lasers through a Bragg grating formed by direct-write ion beam lithography. Method. The selection of longitudinal whispering gallery modes owing to the fabrication of a second-order Bragg grating in the top waveguide cladding layers based on InP was implemented using direct-write ion beam lithography. Main results. The possibility of implementing stable single-mode emission in distributed-feedback ring-cavity surface-emitting quantum-cascade lasers with a Bragg grating formed by direct-write ion beam lithography was demonstrated. An increase in the etching depth of the grooves of the Bragg grating to 2.8 µm facilitated the implementation of stable single-mode emission at a temperature of 83 K. Single-mode emission was observed at a wavelength of 7.45 µm with a threshold current density of approximately 2kA/cm². The maximum side mode suppression ratio was 25 dB. Practical significance. Single-mode distributed-feedback ring-cavity surface-emitting quantum-cascade lasers are promising for the creation of compact gas sensors, wherein a laser and a photodetector of the mid-infrared spectral range are monolithically integrated on one chip.

The nonequilibrium lifetime of charge carriers in a quantum dot has been experimentally and theoretically investigated. It has been shown that, at low temperatures when the ground state is fully occup

Light-emitting devices of modern photonics are based on the semiconductor structures containing layers with various physical parameters. To preserve initial parameters during focused ion beam (FIB) lithography, it is necessary to take into account the processes of radiation defect formation. Radiation-induced defects in target play role of nonradiative recombination centers leading to photoluminescence (PL) quenching. In our work, the FIB impact on the photoluminescence were examined using PL spectroscopy of milled Al_0.18Ga_0.82As/GaAs double heterostructure. In order to exclude photoexcited carriers losses in emitter layer, an experiment with subbarrier photoexcitation was organized. Finally, we compare our experimental findings with theoretical data proposed by stopping and range of ions in matter (SRIM) calculation.

The ion-beam etching of AlGaAs/GaAs heterostructures gives rise to radiation defects and, as a result, leads to photoluminescence quenching. Annealing at 620°C in an atmosphere of As almost...

The effect of annealing temperature and time on the luminescence intensity of the InGaN/GaN heterostructure subjected to ion beam etching was studied. We show that annealing at a temperature...