Spectral behavior of InP-based ring lasers employing multimode interference devices

The performance of ultracompact efficient InP-based ring lasers may degrade due to lasing inside the MMI 3dB coupler. This effect can be reduced by using angled, rough or absorbing end-facets of the MMI section. Optimum MMI lengths maximize decoupling between internal and external resonances. Lasing inside the MMI coupler can be prevented by employing a passive MMI coupler which will also reduce the threshold current. We expect that these findings will lead to further improvement in the performance of these ring lasers.<
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