Abstract

Ultrafast all-optical switching devices are attracting considerable interest as switching elements for future high-bit-rate switching systems. The glass nonlinear coupler is a promising candidate for a practical ultrafast all-optical switch: it offers subpicosecond response times without thermal effects and can operate at rates far higher than those possible with electronic devices. We report experimental studies of switching characteristics of glass dual-core fiber nonlinear couplers with lengths ranging from 5 to 200 cm. These results encompass a range of coupling lengths varying from one to many (where the coupling length is the low-power transfer distance for light to couple from one waveguide of the coupler to the other), whereas our previously reported measurements were for a multiple coupling-length device only. A nonlinear coupler gives particularly useful switching characteristics when it is a single coupling length. Our data include both quasi-cw results using 200-ns Q-switched pulses from a 1.06-μm Nd:YAG laser and the response of slow detectors to 80-ps pulses in a mode-locked Q-switched pulse train from the same laser.

© 1987 Optical Society of America