公开(公告)号：US20220317372A1

公开(公告)日：2022-10-06

申请号：US17218748

申请日：2021-03-31

Applicant: MARVELL ASIA PTE, LTD.

Inventor： Hong CAI ,  Jie LIN

IPC: G02B6/12 ,  G02B6/122 ,  G02B6/136

Abstract: A method for making a multimode interference (MMI) coupler with an arbitrary desired splitting ratio includes forming a thin-film of silicon-nitride material overlying a SOI substrate. The method further includes obtaining geometric parameters of a standard MIMI coupler including a rectangular MMI block and one input port and two output ports in taper shape with one of standard splitting ratios under self-imaging principle which is close to the desired splitting ratio. Additionally, the method includes tunning the input port to an off-center position at front edge of the MMI block. The method further includes making a first output port to a first off-center position flushing with a side edge of the MMI block, adjusting a second output port to a second off-center position. The method includes tunning the MMI block to obtain optimized geometric parameters for approaching the selected arbitrary splitting ratio, and etching the thin-film of silicon-nitride material.