Detection of squeezed light with glass-integrated technology embedded into a homodyne detector setup

We design and demonstrate a homodyne detection scheme based on a glass-integrated optical device (GID) operating in the quantum regime, that is, able to detect genuine nonclassical features. Our device is entirely fabricated by femtosecond laser micromachining. The GID incorporates on the same chip a balanced waveguide beamsplitter and a thermo-optic phase shifter, allowing us to record homodyne traces at different phases and to perform reliable quantum state tomography. In particular, we show that the GID allows for the detection of nonclassical features of continuous-variable quantum states, such as squeezed states.