Abstract

Semiconductor laser diodes are utilized in many applications, in which they are employed as a quasimonochromatic light source that emits a conical beam with an elliptic cross-section. To obtain a laser spot with the required dimensions, a beam shaping system is often used. One of the questions addressed in the design of such a system is how much radiation is entering the entrance pupil of the system; in other words, we are concerned with an evaluation of the encircled energy of laser diode beams. To do this, we begin with the Gaussian formalism of an elliptic beam and then the intensity distribution of the beam is integrated over a circular region to obtain the expression for the encircled energy. Results obtained are compared to experiments performed with an index-guided single-spatial-mode laser diode with wavelength ~670 nm; good agreement between them has been obtained.

© 1991 Optical Society of America