Method of fabricating long period optical grating

摘要

A long period buried optical grating is fabricated by polishing a number of single crystal silicon wafers to identical thicknesses and flat figure, applying a light reflective metallic coating to the wafers, thereafter bonding the wafers together in a stack, and thereafter lapping the resulting stack of bonded layers at an acute angle with respect to the major planar surfaces of the wafers to form the buried grating, such grating having optically flat reflective sawtoothed elements. The grating period may be readily controlled by changing the acute angle and/or the thickness of the silicon wafers.