Phase-incoherent photonic molecules in V-shaped mode-locked VECSELs

Passively mode-locked semiconductor VECSELs realized in a V-shaped cavity configuration ( Fig. 1a ) have proven to provide strong performance figures and are thus promising candidates for photonic applications. Furthermore, these lasers can also be a source of interesting pulsed dynamics, as the double gain pass within one round-trip in the external cavity favors the emergence of pulse clusters over harmonic mode-locking [1] . Here, we investigate this cavity effect in the regime of temporally localized states where the gain relaxation time has to be much shorter than the cavity length.