Patent ID: 6873468

Claim:
An apparatus for lengthening the path of a light beam, comprising: an at least partially enclosed chamber having a first opening and a second opening; a first reflective surface disposed within the chamber and obliquely oriented with respect to an incoming path of the beam, wherein the beam reflects off of the first reflective surface after the beam enters the chamber through the first opening; second and third reflective surfaces disposed within the chamber, the second and third reflective surfaces being generally parallel to the incoming path of the beam, wherein the beam is reflected a plurality of times between the second and third reflective surfaces after the beam is reflected by the first reflective surface; and a fourth reflective surface disposed within the chamber and obliquely oriented with respect to the incoming path of the beam, wherein the beam reflects off of the fourth reflective surface toward and through the second opening after the beam has been reflected a plurality of times between the second and third reflective surfaces.