All-optical inverter based on long-wavelength vertical-cavity surface-emitting laser

An all-optical inverter using transverse mode switching in a 1.5-mu m vertical-cavity surface-emitting laser (VCSEL) was demonstrated theoretically and experimentally. The fundamental mode in a single-mode VCSEL was strongly suppressed when external light was injected into an LP02 high-order mode, resulting in an ON-OFF ratio of over 20 dB. The polarization dependence of the static optical input-output characteristics of inverter operations was as low as similar to 13%. The VCSEL-based optical inverter operated with a 5-Gb/s nonreturn-to-zero (NRZ) input signal. A theoretical result using two-mode rate equations is in good agreement with experimental results.