Influence of the Local Oscillator on Homodyne Detection of Squeezed Vacuum

B. Hüttner, Y. Ben-Aryeh

We use our interpretation of homodyne and heterodyne detection of squeezed states, viz., quantum correlation between photons as expressed in second-order correlation functions, to study various cases. In particular, we introduce the coherence time of the local oscillator and show its influence on the possible noise reduction. We also study the case in which the local oscillator is not much stronger than the squeezed state and analyze the influence of phase jitter. This approach could explain some experimental results and suggest improvements in detection schemes.

Daniel B. Erenso, Hua Deng, Reeta Vyas +1 more

S. Sakata, Seiji Kawamura, Shuichi Sato +4 more

We developed a control scheme of homodyne detection. To operate the homodyne detector as easy as possible, a simple Michelson interferometer is used. Here a motivation that the control scheme of the homodyne detection is developed is for our future experiment of extracting the ponderomotively squeezed vacuum fluctuations. To obtain the best signalto- noise ratio using the homodyne detection, the homodyne phase should be optimized. The optimization of the homodyne phase is performed by changing a phase of a local oscillator for the homodyne detection from a point at which a signal is maximized. In fact, in this experiment, using the developed control scheme, we locked the Michelson interferometer with the homodyne detector and changed the phase of the local oscillator for the homodyne detection. Then, we measured signals quantity changed by changing the phase of the local oscillator for the homodyne detection. Here we used the output from the homodyne detection as the signal.

Masaya Tomita, Aruto Hosaka, Tsubasa Otsuka +1 more

Akihito Omi, Aruto Hosaka, Masaya Tomita +2 more

We generate 1.57-μm squeezed vacuum pulses by degenerate spontaneous parametric down conversion (DSPDC) and observe 3.5dB anti-squeezing and -0.48dB squeezing using local oscillator pulses generated from a degenerate synchronously pumped optical parametric oscillator.

S. A. Wadood, Justin T. Schultz, A. Nick Vamivakas +1 more