Effect of astigmatism on the matching of a laser diode to an external cavity

A theoretical and experimental study has been made of the effect of astigmatism in the placement of a laser diode on the degree to which it is field-matched to a nonselective external cavity. It is shown that the sign and magnitude of the astigmatic displacement determine the type and length of external cavity required for complete field-matching. An expression is obtained for the optimal length of such a cavity.