A space mode selective light source with over 40 GHz direct modulation bandwidth

A high-speed mode selective light source with over 40 GHz direct modulation bandwidth on both 0th and 1st order modes was demonstrated on an active multimode interferometer laser diode (active-MMI LD). By introducing multiple photon-photon resonances (PPR), the bandwidth of small signal frequency response is extremely extended. As the advantage of the active-MMI, the designed PPR frequencies are stable and do not change as the cleaving condition changes. In this work, 1 × 3 asymmetric active-MMI LD was fabricated to introduce multiple PPRs. Over 40 GHz direct modulation bandwidth has been confirmed experimentally on both 0th and 1st order modes.