Photon Blockade Mediated by Two-Photon Absorption in an Optical Parametric Amplifier

Abstract

Photon blockade (PB) is a quantum effect in strongly nonlinear systems where a single photon prevents the system from being excited to a higher level, generating anti-bunched light fields. It enables the generation of single-photon sources for quantum information processing. Conventional photon blockade (CPB) leverages strong nonlinear interactions to generate an anharmonic energy spectrum. Unconventional photon blockade (UPB) utilizes destructive quantum interference between excitation pathways. Recently, environmentally induced photon blockade (EPB) has emerged as a novel approach, exploiting two-photon absorption (TPA) to realize photon blockade. In this work, we combine UPB and EPB together, considering the TPA effect in the optical parametric amplifier (OPA), thereby achieving a more stable PB with stronger suppression of multi-photon states.

Figures (7)

• Figure 1: The schematic of the system under our consideration. An OPA, pumped by a laser with a frequency of $\omega_p$, is coupled with a cavity. There is loss induced by single photon leakage and TPA, corresponding to dissipation rates $\kappa$ and $\kappa_2$ respectively.
• Figure 2: The theoretical results of the amplitude of the steady state using the expression of Eq. (\ref{['eqs:state_description']}). $|C_1|$ and $|C_2|$ are shown in the left and right correspondingly.
• Figure 3: The theoretical and numerical results of $g^{(2)}(0)$ obtained using the same parameters as in Fig. \ref{['fig:theoretical_amplitude']}, with the photon number truncated at 50 in the numerical calculations.
• Figure 4: $g^{(2)}(0)$, $g^{(3)}(0)$ and $g^{(4)}(0)$ under different strength of TPA obtained using the same parameters as in Fig. \ref{['fig:theoretical_amplitude']}, with the photon number truncated at 50 in the numerical calculations.
• Figure 5: $g^{(2)}(0)$, $g^{(3)}(0)$ and $g^{(4)}(0)$ under different TPA strengths at the optimal operating point as in Fig. \ref{['fig:theoretical_amplitude']}. Photon number is truncated at 50 in the numerical calculations. The marks (a)-(f) correspond to the subfigures in Fig. \ref{['fig:six_points']}.