Generation of regular optical pulses in VCSELs below the static threshold

Abstract

We demonstrate theoretically that vertical-cavity surface emitting lasers (VCSELs) under asymmetrical current modulation and external optical injection can generate subnanosecond regular optical pulses below the static threshold. Asymmetrical triangular pump modulation allows the laser to generate irregular pulses, on average, below the static threshold. Injection plays a stabilizing role, reduces the standard deviation of the generated pulses and increases their averaged amplitude. This phenomenon can reduce heating of the laser active medium and can be useful in Information Technology.