Nonlinear Lensing in an Unpumped Antiresonant Semiconductor Disk Laser Gain Structure

We characterize the nonlinear lens in an antiresonant 11 quantum well InGaAs/GaAsP semiconductor disk laser gain structure designed for operation at 1035 nm using a reflection-type z-scan technique. We probe at a wavelength of 1035 nm and with a sub-picosecond pulse duration. The measured n₂ was within the range of -5.6 × 10^-13 cm²/W <; n₂ <; -3.1 × 10^-13 cm²/W.