Analysis of Tunable Internal Loss Caused by Franz-Keldysh Absorption in Transistor Lasers
Journal
IEEE Journal of Selected Topics in Quantum Electronics
Journal Volume
21
Journal Issue
6
Date Issued
2015
Author(s)
Abstract
The Franz-Keldysh (FK) absorption at the base-collector junction of a transistor laser (TL) is inevitable because of the reverse bias therein. The bias condition, thus, plays a crucial role in the determination of internal loss of TLs. In this study, effects from various facet coatings of edge-emitting TLs on the internal loss (αint), which is influenced by the FK absorption, are investigated. Experimental analyses on the electrical and optical characteristics of these TLs at various temperatures are presented. The αint of different coated devices at various bias voltages are then extracted from their light-versus-current curves. We demonstrate that the internal loss resulted from the FK absorption is bias dependent, and therefore tunable. By contrast, the intense field inside the cavity with highly reflective coatings on both facets may saturate the FK absorption and make it less bias controllable.
Type
journal article