All-Optical Directional Switching in Bistable Semiconductor-Ring Lasers

flip-flops; optical bistability; optical logic; optical switches; quantum well lasers; all-optical directional switching; all-optical flip-flops; delay times; directionally bistable semiconductor-ring lasers; energy 150 fJ; lasing directions; optical pulses; reset control signals; set control signals; switching energy; switching times; time 20 ps; time 60 ps; Cavity resonators; Optical waveguides; Ultrafast optics; integrated optics; optical signal processing; semiconductor lasers