Analysis and Optimization of the Input/Output Fiber Configuration in a Laser Package Design

Abstract

The mechanical and thermally induced stresses in the input/output (I/O) fiber in a laser package design are evaluated for different fiber configurations. It is shown that, if the fiber experiences bending deformations, the mechanical stresses can be minimized by applying a proper end off-set. It is found also that, if the optical device can be rotated around the transverse axis by a small angle, this rotation can be effectively used for minimizing the stresses. The smallest fiber span can be achieved, if necessary, by making the fiber straight. In this case the fiber should be short enough to avoid buckling under the action of the compressive stress. We suggest that such a configuration be employed when the appropriate rotation of the device is possible, fiber ends can be easily aligned, and the support structures are strong enough to withstand the elevated thermal force from the compressed fiber. Although the results of the performed analysis can provide guidance for optimizing the I/O fiber configuration, the final selection of such a configuration can be made only after the allowable stress and the achievable end alignment (in the case of straight fiber) are established experimentally.