Fig. 1: Concept of temporal loss boundary interpreted from time and frequency domains.
a A two-mode cavity interpreted in time domain whose optical properties can be continuously tuned by the knob. b The resultant temporal profile radiated from the two-mode cavity. c The idea to tune cavity properties by introducing a temporal loss boundary that acts as a “brake” to hasten the damping rate of oscillation at a selected instant. The two pulses indicate the same truncated oscillations engineered by loss boundary at different instants. Two parameters are defined for the temporal boundary: delay and height. Delay refers to relative time tr between the onset of the detected oscillations (t0) and pump-on instant (tp) of the boundary, and height indicates the strength that determines the rate of “brake.” d Modulation of the two-mode cavity interpreted in frequency domain. Dashed line shows the two modes (TE and TM) of the steady cavity; blue line shows the synchronized modulation of both modes in regime I (tr ≤ 0); and red line shows the asynchronized modulation spectrum in regime II (tr > 0). e, f Height- and delay-resolved spectra by tuning the boundary strength (characterized by conductivity of cavity material) and delay (characterized by time tr), and the resultant evolution of Q factors.
