Fig. 4: Diagram of states.
a–d, System stationary states as a function of EDFA pump power, indicated in the y axis, highlighting the well-defined regions of existence for different types of state. Here these states consist of continuous wave (CW), single and two-soliton states. Stationary states are obtained by increasing the EDFA pump power from the laser threshold. a, Autocorrelation of typical states in the range. b, Optical spectrum. c, Laser scanning spectroscopy of the line at 1,543 nm, the arrows highlight the frequency detuning of the laser modes. The frequency shift of the modes is due to the thermal non-linearity of the microcavity. d, Average frequency detunings for all of the measured laser modes of the microcavity resonances, extracted as in c and measured with respect to the microcavity mode central frequency. e, Full diagram of states obtained over various cavity length settings in addition to the EDFA pump power. White regions are unstable states. Solitons are consistently found in a span of roughly 200 µm, indicating the independence of the system operation from the initial cavity phases of the system. f, Average frequency detuning of the laser mode extracted as in d. Distribution versus EDFA pump power and cavity length. Red to blue points indicate the frequency detuning from −60 to 60 MHz, as in the colour bar.
