Abstract

Nonblocking N × N optical switch arrays (OSAs) are important components for photonic switching in future optical information systems. Several nonblocking 4 × 4 OSAs have been reported, which were made of dielectric materials (LINbO₃). ¹ These devices have the advantage of low crosstalk and low Insertion loss. However, there are Inevitable drawbacks which include a device length larger than 60 mm, strong polarization dependence, and the inability to integrate other active optical devices such as semiconductor lasers and detectors. Recently, we reported the small-size polarization-independent semiconductor optical switch^2-4 with multimode waveguides using a carrier-induced refractive-index change. Utilizing this, a novel single-mode optical switch composed of two Y-branch optical switches and an ×-crossing waveguide is proposed for use as a unit cell of the small-size polarization-independent nonblocking N × N OSA. A nonblocking 4 × 4 OSA integrated with the sixteen proposed optical switches is introduced. Structures and fundamental characteristics of the fabricated 8-mm nonblocking 4 × 4 OSA are also described.

© 1988 Optical Society of America