An er‐doped fiber active switch controlled by coded pump light

Abstract

AbstractIn this paper, a new optical matrix switch using Er‐doped fiber amplifiers is reported. The Er‐doped fiber amplifier acts as an optical gate, depending on the presence or absence of the pump light. The pump light may be a pulsed light whose repetition period is shorter than the fluorescence lifetime. Here the pump light contains interconnection information as a code, and an optical matrix switch where the pump light is distributed through an optical decoder to multiple optical gates is proposed. As a result, an optical matrix switch where the interconnections may be changed by changing the code became possible.In experiments, first, a basic optical gate characteristics were investigated. Using a 20‐mW pump light, the isolation for ON/OFF was 35 dB in the optical gate. In optical gates pumped by pulsed light, it was clarified that there was no influence on the signal light when the repetition rate of the pump light is above 5 kHz. Next, from the above conditions, a 1 × 2 optical switch using an acousto‐optical deflector for the optical decoder was constructed and the switching operation controlled by a coded pump light was demonstrated. The extensibility of matrix size was also investigated; and, by a combination of the proposed switch configuration and Clos‐network construction, it was found that a realization of a 225 × 225 optical matrix switch was possible.