Purification of photon subtraction from continuous squeezed light by filtering
Jun–ichi Yoshikawa, Warit Asavanant, Akira Furusawa · Physical Review A · 2017
Photon subtraction from squeezed states is a powerful scheme to create good approximation of so-called Schr\"odinger cat states. However, conventional continuous-wave-based methods actually involve some impurity in squeezing of localized wave packets, even in the ideal case of no optical losses. Here, we theoretically discuss this impurity by introducing mode match of squeezing. Furthermore, here we propose a method to remove this impurity by filtering the photon-subtraction field. Our method in principle enables creation of pure photon-subtracted squeezed states, which was not possible with conventional methods.