Waveguide optical system

Claim 1

A waveguide optical system comprising a thin light waveguide extending in a plane, a light coupler for receiving a light beam propagated through said light waveguide and directing the light beam to a condensing lens, said condensing lens condensing the light beam emerging from said light coupler into a substantially circular spot, such that said waveguide optical system satisfies the following conditions: 1.2R≦β≦1.4R -0.9R≦Zro≦-0.7R Yo=0 where the width of said emergent light beam in a first direction parallel to the plane defined by said waveguide and perpendicular to an advancing direction of said emergent light beam is 2R, the radius of the pupil of said condensing lens is R, the attenuation distance of the distribution of intensity which decreases exponentially in a second direction perpendicular to said first direction and the advancing direction, of said emergent light beam is β, wherein the Y-axis is taken in a third direction parallel to said plane and perpendicular to the optical axis of said condensing lens, the Zr-axis is taken in a fourth direction perpendicular to said third direction and the optical axis of said condensing lens, the coordinates respecting Zr- and Y-axes of said emergent light beam for a light ray having the maximum intensity which enters the entrance pupil of said condensing lens are Zro, Yo, the origin of the coordinates respecting Zr- and Y-axes is at a center of said entrance pupil and the optical axis of said condensing lens is about parallel to said advancing direction.