Patent ID: 6584241
Filing Date: 2003-06-24
Classification: G02F

Abstract:
A method for switching an optical signal using an optical pump, comprising:inputting an optical signal into an optical loop via a coupler that splits said optical signal into first and second counterpropagating signals; pumping an active portion of said loop with said optical pump, said active portion located asymmetrically in said loop such that said active portion is closer to a first outlet from said loop for said first counterpropagating signal than to a second outlet from said loop for said second counterpropagating signal, said pump causing said active portion of said loop to modify the phases of said first and second counterpropagating signals at the same time, the location of said active portion in said loop causing said first counterpropagating signal to begin to exit said loop at said first outlet with a modified phase at a first time, and causing said second counterpropagating signal to begin to exit said loop at said second outlet with said modified phase at a second time, said second time occurring after said first time and separated from said first time by a time interval determined by a difference between a first length from said active portion to said first outlet and a second length from said active portion to said second outlet; and interfering said first counterpropagating signal with said second counterpropagating signal at said coupler to selectively generate an output signal from first and second output ports of said coupler, said output signal being output from said second port of said coupler during said time interval from said first time to said second time when only said first counterpropagating signal has said modified phase at said coupler, said output signal being output from said first port of said coupler before said time interval, when neither of said first and second counterpropagating signals at said coupler has said modified phase, and after said time interval, when both of said first and second counterpropagating signals at said coupler have said modified phase.