We analyze a new scheme for generating squeezed states in a short semiconductor Al<sub>x</sub>Ga<sub>1−x</sub>As waveguide with X<sup>(3)</sup> nonlinearity at below half the band-gap energy. We find that for a Gaussian pulse the amount of squeezing achievable is limited by the squeezed-state detection phase mismatch caused by the pump self-phase modulation and is also degraded slightly by the pump–probe phase mismatch that is due to the different nonlinear refractive indices experienced by the pump and the probe beams. We show theoretically that the amount of squeezing observed can be increased by use of either a short pulse or a pulse with matched phase variation as the local oscillator. In a centimeter-long Al<sub>x</sub> Ga<sub>1−x</sub>As waveguide more than 85% (8.2 dB) of squeezing potentially can be obtained, limited mainly by two-photon absorption.
© 1995 Optical Society of America
Seng-Tiong Ho, Xiaolong Zhang, and Maria K. Udo, "Single-beam squeezed-state generation in semiconductor waveguides with X(3) nonlinearity at below half-band gap," J. Opt. Soc. Am. B 12, 1537-1549 (1995)