Abstract: A quantum random number generator includes an entropy source having a laser source, a single photodiode configured for generating photo current based on received light from the laser source, where the photodiode has a non-unity quantum efficiency for allowing interference of the light from the laser source with a vacuum state to obtain entropy from the vacuum state, a transimpedance amplifier to convert the photo current into voltage, an analog-to-digital converter for converting the analog voltage to a digital output, a security proof which establishes a lower bound on the entropy from the vacuum state, and a processing unit configured to convert the digital output from the analog-to-digital converter to random numbers based on the security proof.

Abstract: A squeezed light generator (SLG) for generating squeezed light (SQL) is disclosed, said squeezed light generator (SLG) comprising: —a waveguide (WG) being arranged to receive fundamental wavelength laser light (FWL), the waveguide (WG) comprising a second harmonic generator (SHG) for generating second harmonic light (SHL) from the fundamental wavelength light (FWL), —an optical cavity (OC) resonant for both fundamental wavelength light (FWL) and the second harmonic light (SHL), the optical cavity (OC) being arranged to receive the second harmonic light (SHL), and —a parametric down converter (PDC) arranged inside said optical cavity (OC), the parametric down converter (PDC) being adapted for generating said squeezed light (SQL) using said second harmonic light (SHL). Also, a method for generating squeezed light (SQL) is disclosed.

Abstract: A squeezed light generator (SLG) for generating squeezed light (SQL) is disclosed, said squeezed light generator (SLG) comprising: —a waveguide (WG) being arranged to receive fundamental wavelength laser light (FWL), the waveguide (WG) comprising a second harmonic generator (SHG) for generating second harmonic light (SHL) from the fundamental wavelength light (FWL), —an optical cavity (OC) resonant for both fundamental wavelength light (FWL) and the second harmonic light (SHL), the optical cavity (OC) being arranged to receive the second harmonic light (SHL), and —a parametric down converter (PDC) arranged inside said optical cavity (OC), the parametric down converter (PDC) being adapted for generating said squeezed light (SQL) using said second harmonic light (SHL). Also, a method for generating squeezed light (SQL) is disclosed.