A non-Gaussian state being a mixture of the vacuum and single-photon states can be generated by truncating a thermal state in a quantum scissors device.

We find that the success probability is a linear decreasing function of the transmissivity for a given thermal photon number.

It is found that the signal amplification and the signal-to-noise ratio enhancement can occur for large transmissivity.

By tuning interaction parameters, the negativity of the Wigner function can exhibit for large transmissivity.