Mid-infrared type-I InGaSb/GaSb quantum well SESAM

A Semiconductor Saturable Absorber Mirror (SESAM) is a key optical component used extensively for passively modelocking of diode-pumped solid-state and semiconductor disk lasers. Modulation depth (ΔR), saturation fluence (F sat ), non-saturable losses (ΔR ns ) and recovery times are the key parameters of a SESAM, which depend on semiconductor layer design and growth parameters. It has been shown that the recovery dynamics of InGaSb-based mid-infrared (mid-IR) SESAMs are less effected from low-temperature growth of the absorber layer and strain unlike InGaAs-based near-infrared SESAMs [1] . Here we demonstrate type-I InGaSb/GaSb quantum well (QW) based SESAMs operating well above 2 µm with full nonlinear reflectivity and pump-probe characterizations for the first time.