Robust squeezed light against mode mismatch using a self imaging optical parametric oscillator

Abstract

We present squeezed light that is robust against spatial mode mismatch (beam displacement, tilt, and beam-size difference), which is generated from a self-imaging optical parametric oscillator below the threshold. We investigate the quantum properties of the generated light when the oscillator is detuned from the ideal self-imaging condition for stable operation. We find that the generated light is more robust to mode mismatch than single-mode squeezed light having the same squeezing level, and it even outperforms the single-mode infinitely squeezed light as the strength of mode mismatch increases.

Quadrature squeezing of 10 4 spatial modes via manipulation of diffraction

“…In other words, the spatial squeezing is homogeneous in the probe regime. This is in contrast to the case of single-mode squeezing where the observed squeezing will be degraded considerably for increasing mode mismatch [40][41][42][43]. The squeezing decreases from −15.33 dB at w L /w p = 1 to around −1.51 dB at w L /w p = 0.01, suggesting localized squeezing at ∼10 2 μm 2 and alternatively 10 4 of spatially squeezed modes in the probe regime which is of an area 1 mm 2 .…”