Patent ID: 7088517
Filing Date: 2006-08-08
Classification: G02B

Abstract:
1. A beam splitter for splitting a beam of light, comprising: pairs of mirrors, including n pairs of mirrors wherein n is an integer equal to 2 or greater, each of said pairs of mirrors including a first mirror and a second mirror having reflective surfaces disposed opposing one another, said pairs of mirrors being serially disposed relative one another in a downstream transmission direction extending from an input end to an output end, wherein a 1 a planar optical substrate having a substrate surface defining a substrate plane disposed between said first mirror and said second mirror of each of said pairs of mirrors, said substrate surface including a first surface portion and a second surface portion arranged adjacent a side of said first surface portion nearest said output end; said first surface portion being semi-reflecting, permitting partial light transmission through said planar optical substrate and permitting partial light reflection from said planar optical substrate; said second surface portion being highly transmissive and antireflective permitting light transmission through said planar optical substrate; said planar optical substrate being movably disposed to move in said substrate plane in an upstream transmission direction from a first position to at least a second position thereby shifting said first surface portion and said second substrate portion relative to said pairs of mirrors; said first position providing a first relative arrangement of said pairs of mirrors and said planar optical substrate wherein said first surface portion is interposed between said first and second mirrors of said pairs of mirrors to receive and direct light from and to said pairs of mirrors, each of said pairs of mirrors in conjunction with said planar optical substrate defining a mirror pair section such that for each of said mirror pair sections: said mirror pair section output from said 1 said mirror pair section output of said n said second surface portion is positioned to a downstream transmission side of said n said second position providing a second relative arrangement of said pairs of mirrors and said planar optical substrate wherein said first and second surface portions are shifted in an upstream transmission direction, from locations when in said first position, and said second relative arrangement differs from that of said first relative arrangement in that: said second surface portion replaces said first surface portion in receiving incident thereon said mirror pair section output from said (n+1−m) th pair of mirrors through said n