Abstract: Tube lenses for imaging instruments are described herein. The tube lenses may be implemented with imaging instruments that include an objective lens that is not entirely infinitely corrected. A tube lens may include: a first optical element configured to receive diverging light from an objective lens along an optical path between the objective lens and the tube lens, and a second optical element. The first optical element converges the diverging light received from the objective lens onto the second optical element, and the first element is movable along its longitudinal axis relative to the second optical element.

Abstract: A reflaxicon system comprising two or more reflaxicons, either, neither, or both of which can be formed of solid light transmitting material, is provided and described for use and implementation as objectives, relays, and beam expanders. Each reflaxicon features a central substantially cone shaped surface and a distal surface shaped like a truncated cone with both of said surfaces aligned with and symmetrically arranged around a central axis. In the system provided said central axes are aligned and form the optical axis of the system and further curvatures can be provided to any of said surfaces as well as to incident and exiting system surfaces to provide additional optical effects as required for different applications. Further, the conical surfaces forming the central reflectors can each or both be convex or concave, with ease of construction mitigating in favor of dual concave central reflectors as the preferred embodiment.

Abstract: A reflaxicon system comprising two or more reflaxicons, either, neither, or both of which can be formed of solid light transmitting material, is provided and described for use and implementation as objectives, relays, and beam expanders. Each reflaxicon features a central substantially cone shaped surface and a distal surface shaped like a truncated cone with both of said surfaces aligned with and symmetrically arranged around a central axis. In the system provided said central axes are aligned and form the optical axis of the system and further curvatures can be provided to any of said surfaces as well as to incident and exiting system surfaces to provide additional optical effects as required for different applications. Further, the conical surfaces forming the central reflectors can each or both be convex or concave, with ease of construction mitigating in favor of dual concave central reflectors as the preferred embodiment.