Quantum well saturable absorber mirror with electrical control of modulation depth

We demonstrate a quantum well (QW) semiconductor saturable absorber mirror (SESAM) comprising low-temperature grown InGaAs/GaAs QWs incorporated into a p-i-n structure. By applying the reverse bias voltage in the range 0-2 V to the p-i-n structure, we were able to change the SESAM modulation depth in the range 2.5-0.5%, as measured by nonlinear reflectivity of 450 fs long laser pulses with 1065 nm central wavelength, in the pump fluence range 1.6-26.7 mu J/cm(2). This electrical control of the modulation depth is achieved by controlling the small-signal loss of the SESAM via quantum-confined Stark effect in the QWs. (C) 2010 American Institute of Physics. [doi:10.1063/1.3474799]