Parametric oscillation with a squeezed vacuum

Berihu Teklu

Kokeb B. Benti, Desalegn Ayehu

A degenerate optical parametric oscillator (DOPO) in the above threshold regime is a prominent source of squeezed field. In this study, a driven DOPO whose pump mode is coupled to a thermal bath while the signal mode is coupled to a squeezed vacuum reservoir is explored to understand the effect of the external squeezed light and the thermal fluctuations on the squeezing properties of both the intracavity and output pump and signal modes. Our findings showed that the injected squeezed vacuum reservoir enables the intracavity squeezing to surpass the maximum squeezing limit of 50% attainable in a DOPO coupled to an ordinary vacuum reservoir. We also found that the maximum squeezing of the output signal mode shifts from resonance to off-resonance in the presence of the injected squeezed vacuum field. Furthermore, the output pump mode exhibits nearly perfect squeezing for a squeezing parameter of r=2. Unlike the output signal mode, the maximum squeezing of the output pump mode occurs at resonance in the presence of the injected squeezed vacuum reservoir. Moreover, a considerable amount of squeezing is observed even in the presence of thermal fluctuations, as they are counterbalanced by the external squeezed light. Notably, relative damping rate between the pump and signal modes is observed to be a parameter that significantly influences squeezing, indicating the importance of optimizing the amount of damping depending on the intended purpose of the DOPO.

Paolo Tombesi

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.

E. Giacobino

Z. Ficek

Summary form only given. We extend the analytical technique to the case of a fully quantized dressed-atom model with a detuned driving laser field and incorporate the cavity effect on the fluorescence spectrum. We find that the population trapping effect, predicted for the broadband squeezed vacuum case, may appear in a narrow-bandwidth squeezed vacuum only if there is nonzero squeezing at the Rabi sidebands. We show that this condition is readily achieved with a squeezed vacuum that is the output from a nondegenerate parametric oscillator, whereas for a squeezed vacuum that is the output from a degenerate parametric oscillator a squeezing bandwidth comparable to the Rabi frequency is required.