Lightwave fiber tap

Abstract
This paper describes a device which samples the optical signal in an optical fiber for use in source stabilization via feedback control. This device incorporates a beam splitter formed on the fiber ends to deflect a portion of the light traveling down the fiber into a P-I-N photodetector. Advantages of this device include low insertion loss, an output that is relatively independent of the modal distribution within the fiber, and is a rugged small package.