Pigtailed Single-Mode Diode Lasers

摘要

In choosing a scheme for single mode fiber coupling, the final evaluation should of course be based on an experimental comparison between the alternative. However, such an evaluation will generally not reveal the essential limitations of any scheme. While the possible sources of less than ideal performance are well known, their relative significance is not so obvious. It is clear that in order to make significant improvements in the state of fiber coupling technology, the relevant limitations must be clarified in order to guide further efforts in fruitful directions. As such, we have conducted an analysis of several aspects of the fiber coupling problem which is presented here. Preliminary to the consideration of any particular system, the importance of the zeroth and first order properties of the coupling system are briefly discussed. To go beyond this, the higher order aberrations of the optical coupling system must be included in the analysis. To do this, an algorithm to calculate the mode coupling performance of any optical system has been developed using the ray tracing features of an optical design program. This algorithm is described along with the results of an analysis of coupling with graded index lenses which have been found to work well experimentally. (RH)