  The perfect soliton crystal (PSC) was recently discovered as an extraordinary
Kerr soliton state with regularly distributed soliton pulses and enhanced comb
line power spaced by multiples of the cavity free spectral ranges (FSRs). The
modulation of continuous-wave excitation in optical microresonators and the
tunable repetition rate characteristic will significantly enhance and extend
the application potential of soliton microcombs for self-referencing comb
source, terahertz wave generation, and arbitrary waveform generation. However,
the reported PSC spectrum is generally narrow. Here, we demonstrate the
deterministic accessing of versatile perfect soliton crystals in the AlN
microresonators (FSR ~374 GHz), featuring a broad spectral range up to 0.96 of
an octave-span (1170-2300 nm) and terahertz repetition rates (up to ~1.87 THz).
The measured 60-fs short pulses and low-noise characteristics confirms the high
coherence of the PSCs
