Author Affiliations
1Shanghai Jiao Tong University, School of Physics and Astronomy, State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai, China2Shanghai Research Center for Quantum Sciences, Shanghai, China3Shandong Normal University, Collaborative Innovation Center of Light Manipulation and Applications, Jinan, Chinashow less
Fig. 1. Configuration of a synthetic photonic stub lattice. (a) Two coupled ring resonators, where the FSR of ring is half of the FSR of ring , i.e., . Ring undergoes dynamic modulation by placing an EOM with the modulation frequency . Waveguides are connected to rings for input/output signals. (b) The system in (a) can be mapped into a photonic stub lattice along the synthetic frequency dimension (), with , , and indicating three types of lattice sites. (c) The corresponding band structures of the synthetic stub lattice in (b) with and .
Fig. 2. Band structure measurements for the case of . (a1)–(d1) Experimentally observed band structures with different modulation amplitudes . (a2)–(d2) Simulation results of the projected output intensity distribution of the band structure on mode , based on Eqs. (4)–(6), where takes different values with fixed and . (a3)–(d3) Measured transmission spectra from the drop port of ring . The vertical axis represents the frequency detuning of the input laser source normalized to , while the bottom horizontal axis in (a1)–(d2) represents one roundtrip time in ring with the period of .
Fig. 3. Band structure measurements for the case of . (a1)–(c1) Experimentally observed band structures varied with . (a2)–(c2) Simulation results of the projected intensity distribution of the band structure on modes and , based on Eqs. (4), (5) and (7), (8), with and . (a3)–(c3) Transmission spectra measured from the drop port of ring . The bottom horizontal axis in (a1)–(c2) represents one roundtrip time in ring with the period of .
Fig. 4. Mode distributions for the case of . (a) Experimentally resolved resonant mode spectra as a function of frequency detuning with . (b) The corresponding mode distributions of two selected input frequencies in (a) located at and , respectively. (c) Simulated resonant mode spectra with , and (d) the corresponding intensity distributions of the two chosen input frequencies at and , respectively. The horizontal axis represents the mode number for the frequency .
Fig. 5. Observations of flat-to-nonflat band transition for the case of . (a1)–(d1) Experimentally measured band structures with different long-range modulation amplitudes and fixed . (a2)–(d2) Simulation results of the projected intensity distribution of the band structure on mode varied with , where , , and .