An Optical Power Splitter With Variable Power Splitting Ratio

An optical power splitter based on two parallel and identical spot-size mode converters is proposed. The mode converters are used to couple light directly from a lensed single-mode fiber, and lights in the mode converters are further separated with respective connecting s-bend waveguides. Factors affecting coupling efficiency and power splitting ratio of the device have been investigated with simulations. An optical power splitter based on silicon-on-insulator has been fabricated and optically characterized. Both the simulations and experiments show that the splitter can achieve variable optical power splitting ratio and have very low excess loss. The splitter can also be inversely used to combine two beams from a photonic integrated circuit into a fiber.