procedures for amending the upgraded and phase relations in multi - mode interference kopplern

摘要

PCT No. PCT/CH94/00207 Sec. 371 Date Aug. 4, 1995 Sec. 102(e) Date Aug. 4, 1995 PCT Filed Oct. 18, 1994 PCT Pub. No. WO95/12828 PCT Pub. Date May 11, 1995The invention relates to the field of integrated optics and communication techniques. In these fields, integrated, compact passive beam splitters and combiners are of great importance. These optical functions can be fulfilled by means of multimode interference (MMI) couplers. A given number of inputs is evenly distributed to all outputs. These components have wide manufacturing tolerances and are substantially independent of polarization. In the conventional MMI couplers with parallel sides, the intensity and phase distribution at the output are fixed. However, since in many applications, these distributions must be influenced in a controlled manner, the invention provides a method of changing the intensity and phase distributions at the outputs of MMI couplers in a controlled manner. The conventional MMI couplers are first split up into sections. Each section is then separately transformed so that the self-imaging properties are maintained. At the end, the sections are arranged in series again. By appropriate choice of the transformations, different controlled beam splitters and combiners can be obtained. The distributions are changed by means of a simple, tolerant control of geometrical parameters.