Fig. 2: High cooperativity bidirectional conversion.
From: Quantum-enabled operation of a microwave-optical interface
Top (bottom) row panels show results for microwave-to-optics (optics-to-microwave) conversion. a, e Converted signal pulses (bright dots are calibrated measurements and lines are theory) for a 300 ns-long optical pump pulse measured with a 500 Hz repetition rate for a CW signal (solid lines) and a pulsed signal (dashed lines). b, f Measured IQ quadrature modulation of the converted signal pulse (red lines) and the applied IQ quadrature modulation to the input signal (gray dashed lines) for C = 0.49. c, g Converted signal pulses (bright dots are calibrated measurements and lines are theory) for a 100 ns-long optical pump pulse and a CW signal measured with a 500 Hz repetition rate. d, h Summary of measured steady-state (blue squares) and peak (red squares) total transduction efficiency (left axis) and internal transduction coefficient (right axis) as a function of the in-pulse pump power Pp and cooperativity. Blue lines show the theoretical prediction for the steady-state (Eq. (2)) and orange lines for the peak values (see Supplementary Information), respectively. Solid lines are theory taking into account the finite suppression ratio \({{{{{{{\mathcal{S}}}}}}}}=0.22\), whereas the dashed lines are for the ideal case \({{{{{{{\mathcal{S}}}}}}}}=0\). The blue dashed line indicates the achieved C-dependent steady-state pure conversion efficiency and the blue-shaded area highlights the calculated gain of the measured steady-state transduction efficiency owing to finite sideband suppression. The vertical (smaller than the symbols) and horizontal error bars represent the standard error of the individual measured time-averaged values.
