Contents Introduction
Cost of optical components is a crucial factor in development of Metro-communication networks. One aspect of cost reduction is the use of optical components, which do not require temperature stabilization. In the present communication we describe development and optimization of pump laser diodes for erbium-doped fiber amplifiers (EDFA) working without active cooling at temperatures of more than 70°C. In principle, fiber Bragg grating (FBG) stabilized pump laser diodes are perfect devices for so called un-cooled operation, since, DFB or DBR stabilized pumps exhibit a much stronger wavelength shift with changing temperature [1]. However, reliability concerns, threshold current increase, and efficiency drop at temperatures above 60°C did not allow the use of these devices at operating temperatures above 50 Targeting Laser diodes with excellent opto-electronic properties to enable high temperature/high power operation, we have focused on the development of thermally optimized devices by using new 2D and 3D simulation tools (see Fig. 1). The resulting devices with very low intemallosses of around t em” and optimized thermal properties reach rollover powers of up to 1.4 W at 25°C and more than 800 mW at 85 “C. In addition to the thermal stability; locking performance has been improved to guarantee FHG-stabilized high power operation at temperatures above 70C”.
3D Simulation of a ridge laser. Due to the low front and high back facet reflectivity, the optical field in the laser cavity increases towards the front facet. [2].
