Patent ID: 7554674

Claim:
An apparatus comprising: a source of optical energy having a first wavelength, wherein the source enables the propagation of the optical energy along a first direction; an optically resonant cavity comprising a first surface and a second surface that collectively define the optically resonant cavity, wherein the optically resonant cavity distributes received optical energy having the first wavelength into a first portion and a second portion, and wherein the ratio of the first portion and the second portion is based on an environmental stimulus; and a lens having a central optical axis; wherein the source, lens, and optically resonant cavity are arranged such that; (1) the lens receives the optical energy from the source, wherein the received optical energy is centered at a point that is displaced from the central optical axis; (2) the lens redirects the optical energy so that the optical energy propagates along a second direction toward the optically resonant cavity, wherein the first direction and the second direction are non-co-linear; and (3) the optically resonant cavity receives the optical energy that propagates along the second direction, wherein the second direction is non-orthogonal with the first surface.