Abstract: A self-starting mode locking soliton device includes a first optical port to accept an input coherent light. A second optical port provides an output comb of a plurality of wavelengths. A comb resonator with optical Kerr nonlinearity and anomalous group-velocity dispersion is optically coupled to both of said first optical port and said second optical port. The resonator includes an optical property of a negative nonlinear bistability to enable the self-starting mode locking of a Kerr soliton comb. A method of self-starting mode locking is described. A method of producing the negative nonlinear bistability is also described.