Improved light-output linearity in stripe-geometry double-heterostructure (Al,Ga)As lasers

Abstract

Nonlinearities in the optical-power-output–versus–current characteristics of (Al,Ga)As stripe-geometry double-heterostructure lasers are found to be associated with excessive spectral broadening, asymmetries in the outputs from the two mirrors, and spatial movements of the lasing mode within the width of the stripe. Manifestations of these nonlinearities are severely deleterious in a variety of optical fiber communication applications. It is shown that the impact of these defects may be significantly reduced, with little lasing-threshold-current penalty, by fabricating devices with narrower stripe widths.

Criterion for improved linearity of 1.3-µm InGaAsP-InP buried-heterostructure lasers

“…Thus our measurements and calculations show that the L-I nonlinearities occur at a higher power in lasers with smaller active-region width. This is due to the rapid decrease of the confinement factor of the higher order modes with decreasing active width, These results for index-guided lasers are very similar to the analogous observation by Dixon et al [9] for proton stripe gain-guided AlGaAs lasers.…”

Derivative Measurements of Light-Current-Voltage Characteristics of (AI,Ga)As Double-Heterostructure Lasers

“…A device with significant curvature in the L-I was used as an example to illustrate the enhancement of such slope changes using the derivatives. As expected from earlier results, 4 the emission from the two laser mirrors was often unsymmetric and was usually very unsymmetric when L-I kinks 6 were present. These kinks are thought 4 to be associated with spatial inhomogeneities in the laser cavity.…”

“…As expected from earlier results, 4 the emission from the two laser mirrors was often unsymmetric and was usually very unsymmetric when L-I kinks 6 were present. These kinks are thought 4 to be associated with spatial inhomogeneities in the laser cavity. This nonsymmetry was also present in the light-current derivatives.…”