Adjustable optical signal delay module and method thereof

Abstract

An adjustable optical signal delay module which adjusts power of an amplified spontaneous emission generated by a semiconductor optical amplifier and feeds the adjusted amplified spontaneous emission back to the semiconductor optical amplifier in a direction opposite to an optical signal being amplified by the semiconductor optical amplifier is provided. The feedback of the adjusted amplified spontaneous emission varies a group refractive index of the semiconductor optical amplifier and delays the transmission of an optical signal through the semiconductor optical amplifier. By that arrangement, the adjustable optical delay module obviates the need for the pump laser conventionally required by a coherent population oscillation mechanism. The feedback optical loop includes a variable optical attenuator, an optical filter, and optical circulators. A user can control the delay timing of optical signals via adjusting optical power in the feedback optical loop.