Abstract: The present invention adjusts the relationship of two optical components within an optical coupler by the use of eccentric sleeves. As individual eccentric sleeves of an adjustable subassembly are rotated, they change either the angle or the location of the axis of one optical component relative to the location of the axis of another fixed optical component. Adjustment of the alignment of the optical components therefore requires only the rotation of the sleeves of the adjustable subassembly. Locking the sleeves into a selected adjustment is accomplished by the insertion of a low expansion, quick setting, bonding agent into holes located so that they feed the bonding agent into the spaces between the sleeves. Thus, after the bonding agent has fused together the otherwise movable parts, any further movement of the sleeves is prevented, and the alignment is permanently preserved.

Abstract: The apparatus is an attenuator for use in an optical fiber link. The attenuator is a full circular loop of continuous optical fiber with connection means at the ends of the loop to interconnect with the other optical fiber components in the system. The attenuation of optical transmission through the loop is continuously variable by twisting the loop out of its original planar configuration. A lockable rotating shaft clamped to the side of the loop remote from the connection means is turned to rotate the loop.