A confined-field laser has been properly designed so that its absorption loss due to interband transitions is negligible (αIB ∼= 0). The free carrier absorption loss and the scattering loss are αFC =...

A confined-field laser has been properly designed so that its absorption loss

due to interband transitions is negligible (αIB ∼= 0). The free carrier absorption loss and the scattering loss are αFC = 5 cm−1 and αS = 0.5 cm−1, respectively. If the length of the laser is increased by a factor of two, by what factor

will the threshold current density change? (Assume the end face reflectivity

is 65%).