An optical tracking system comprising: an autoclavable fiducial marker assembly comprising: an opaque housing defining an interior cavity , a light emitting semiconductor die disposed in the interior cavity and in electrical communication with an anode and a cathode , a window panel joined to the opaque housing to enclose the interior cavity between the window panel and the opaque housing , the window panel configured to refract a plurality of light rays emitted by the light emitting semiconductor die, and a metallized coating forming a hermetic seal at an interface of the window panel and the opaque housing , wherein the fiducial marker assembly is configured to shield a peripheral edge of the window panel from the plurality of light rays; a tracking device comprising at least two optical sensors , each optical sensor configured to detect a position of a light ray of the plurality of light rays; a processor; and a non-transitory, computer-readable medium storing instructions that, when executed, cause the processor to: receive the position of each light ray from each optical sensor , characterized in that the non-transitory, computer-readable medium stores instructions that, when executed, cause the processor to: shift the position of each light ray based on a calculated refraction deviation, and triangulate the location of the light emitting semiconductor die based on the shifted position of each light ray. an autoclavable fiducial marker assembly comprising: an opaque housing defining an interior cavity , a light emitting semiconductor die disposed in the interior cavity and in electrical communication with an anode and a cathode , a window panel joined to the opaque housing to enclose the interior cavity between the window panel and the opaque housing , the window panel configured to refract a plurality of light rays emitted by the light emitting semiconductor die, and a metallized coating forming a hermetic seal at an interface of the window panel and the opaque housing , wherein the fiducial marker assembly is configured to shield a peripheral edge of the window panel from the plurality of light rays; an opaque housing defining an interior cavity , a light emitting semiconductor die disposed in the interior cavity and in electrical communication with an anode and a cathode , a window panel joined to the opaque housing to enclose the interior cavity between the window panel and the opaque housing , the window panel configured to refract a plurality of light rays emitted by the light emitting semiconductor die, and a metallized coating forming a hermetic seal at an interface of the window panel and the opaque housing , wherein the fiducial marker assembly is configured to shield a peripheral edge of the window panel from the plurality of light rays; a tracking device comprising at least two optical sensors , each optical sensor configured to detect a position of a light ray of the plurality of light rays; a processor; and a non-transitory, computer-readable medium storing instructions that, when executed, cause the processor to: receive the position of each light ray from each optical sensor , characterized in that the non-transitory, computer-readable medium stores instructions that, when executed, cause the processor to: shift the position of each light ray based on a calculated refraction deviation, and triangulate the location of the light emitting semiconductor die based on the shifted position of each light ray. shift the position of each light ray based on a calculated refraction deviation, and triangulate the location of the light emitting semiconductor die based on the shifted position of each light ray. <EOS>