  Phase-squeezed light can enhance the precision of optical phase estimation.
The larger the photon numbers are and the stronger the squeezing is, the better
the precision will be. We propose an experimental scheme for generating
phase-squeezed light pulses with large coherent amplitudes. In our scheme, one
arm of a single-photon Mach-Zehnder interferometer interacts with coherent
light via a non-linear optical Kerr medium to generate a coherent superposition
state. Post-selecting the single photon by properly tuning a variable beam
splitter in the interferometer yields a phase-squeezed output.
