Patent ID: 7253970

Claim:
A lens arrangement comprising: a first element having a concave reflective surface and defining an optical axis of the lens arrangement, and a second substantially flat and at least partially reflective element spaced-apart from the first element along the optical axis, the second element being configured to allow light passage therethrough and being oriented with respect to the optical axis and the first element such that at a predetermined angle of incidence of an input light beam onto the second element, the input light beam is reflected onto the reflective surface of the first element and reflected therefrom to pass through the second element, wherein the second element is an apertured mirror oriented such that the optical axis passes through the aperture, and at the predetermined angle of incidence of the input light beam onto the reflective surface of the second element, the input light beam is reflected onto the reflective surface of the first element and reflected therefrom towards the aperture in the second element, and wherein the aperture has a substantially conical geometry with a cone base being at an outer surface of the second element.