摘要 |
An apparatus for the conduction of light. The apparatus includes two concave refracting elements, such as spherical mirrors or concave gratings, such that a connecting line segment between centers of the elements forms with a main axis of a first element an angle of incidence in excess of zero, and with a main axis of a second element an angle of incidence equal in size but in a plane perpendicular to the plane defined by the connecting line segment and the main axis of the first element. Thus, astigmatism error can be corrected. The apparatus is applicable in optical analyzers for conduction of measuring light to or from a sample. |