Structure optimization of high speed intracavity-contacted oxide-confined VCSELs
This work presents the simulation of the intracavity contacted oxide confined vertical cavity surface emitting lasers (VCSEL) including the thermal effects. The analysis of thermal, electrical and optical phenomena represents the influence of geometrical parameters on power and modulation properties on such devices.
Current crowding in graded contact layers of intracavity-contacted oxide-confined vertical-cavity surface-emitting lasers
In this work we present the simulation of the intracavity-contacted oxide-confined vertical-cavity surface-emitting lasers including the thermal effects. We analyze the thermal, electrical, and optical properties of such devices with the different thicknesses of graded layers between the contact and oxide confined layers. Results of simulations for the devices with graded layer thickness of 40–60 A show a reduced current crowding effect.
One hundred percent tumor induction in mouse skin after repeated beta irradiation in a limited dose range.
Repeated beta irradiation of the backs of mice three times a week with radiation doses of 250 to 1180 cGy per exposure induced 100% incidence of tumors. The incidence of skin tumors appeared to be determined by the total number of repeated exposures in this dose range. An abrupt delay in tumor emergence was observed when the radiation dose was reduced from 250 to 150 cGy per exposure, indicating the existence of a critical threshold. Mouse skin resembles human skin rather than rat skin in its response to radiation.