Current modulation by using dual color quantum cascade laser
Keywords:Dual-color quantum cascade lasers, rate equations model, current modulation.
Mathematical model to describe electrons and photons in dual color quantum cascade lasers has been proposed. These lasers have the ability to generate laser light in micrometer scale. The model consists of six differential equation for describing change concentration of electrons and photons with time . two of those equations express the first and second wave length photons . the rest equations show electron movement in four electronic levels . then equations to modulate injected current in active region have been employed by using sine function and photons demonstrate electrons variety with time effect of number of gain region , modulation frequency , continuous injection current , alternative injection current on electrons and photons distribution in active region have been studied . The results pointedout increasing in electrons and photons number as the continuous current and gain region number increase as compared with increasing in its number as the alternative current increase .
One can observed distribution of electrons in the second electronic level with increasing number of gain regions does not change .one can conclude in fluency number of gain regions on this region is weak . the results denoted to change in electrons and photons distribution as the frequency modulation change