Abstract: A magneto-optical current measuring device includes a collimating lens arrangement for focusing a light signal into a parallel beam of light, which beam of light, when polarized is communicated through a Faraday rotator which is disposed in surrounding proximity to the transmission line in which it is desired to measure the current flow. The collimating lens element is formed of a segment of a parabolic lens and a spacer lens element which has a flat surface formed by an edge opposite the parabolic surface, this flat surface extending to the focal length of the parabolic surface. The collimating lens element is constructed in the manner of a monolithic configuration and is then secured together with the polarizing element to the Faraday rotator in a manner so as to eliminate all air-to-glass interfaces.

Abstract: Apparatus for fixing eyeglasses within a protective mask is disclosed, the eyeglasses being adjustable vertically. An attaching bar is fixed to the viewing glass of the mask, the attaching bar having two or more notches vertically spaced. A carrier has the eyeglasses attached, and the carrier has tabs to be received by the notches. The vertical position of the eyeglasses is fixed by selecting the appropriate notches.

Abstract: An optical fiber termination in which a plastic clad optical fiber is pushed into a heated ferrule containing a pierced watch bearing jewel so as to force the bare fiber through the aperture in the jewel. The protruding fiber end is then fused and polished flush with the jewel whereby the fiber end is centered within the jewel aperture.