Quantum-noise reduction at frequencies up to 0.5 GHz using pulsed parametric amplification

Measurements of quantum-noise reduction have been performed over a broad frequency range up to 0.5 GHz using pulses of squeezed light generated by parametric amplification in ${\mathrm{KTiOPO}}_4$ crystals. Both balanced-homodyne and direct-difference photodetection schemes were employed, and 0.5 dB of noise reduction was routinely obtained. A continuous-mode traveling-wave theory including the effects of dispersion and loss has been employed to model the experimental results.