Optical inverter using a vertical-cavity surface-emitting laser with external light injection

In this paper, we present the measurement on the optical input-output characteristic of 1.55 /spl mu/m InP based VCSELs with an external light injection either to its fundamental transverse mode or 1st-high-order transverse mode. It is shown that when the wavelength of the external light was set to be slightly longer than that of the mode, the abrupt modal switching, enabling the function of an optical inverter, was observed for both cases.