Fig. 1. Schematic diagram of the dual-mode DBR laser-packaged device.

Fig. 2. Material structure schematic diagram of the ridge laser.

Fig. 3. Near-field mode pattern of the laser with (a) 2 μm ridge, supporting only the fundamental mode, (b) 3.5 μm ridge, supporting both the fundamental mode and the first-order mode, and (c) 6 μm ridge, supporting the fundamental mode, the first-order mode, and the second-order mode.

Fig. 4. Beating frequency of the fundamental mode and the first-order mode as a function of the ridge width. Inset (a) is the cross section of the material layers; (b) and (c) are the mode distributions of the fundamental mode and the first-order mode, respectively.

Fig. 5. Map of the output optical spectra when only the gain current was tuned.

Fig. 6. (a) Typical output spectrum of the device in (a) the fundamental mode and (b) the dual-mode state. The insets show the near-field intensity distribution in (a) the fundamental mode operation state, and (b) the dual-lateral-mode operation state.

Fig. 7. (a) Autocorrelation trace of the device, where the wavelength difference between the two modes is 9.68 nm, corresponding to 1.21 THz at IGain=140  mA, IPhase=10  mA. (b) Autocorrelation trace of the device, where the wavelength difference between the two modes is 8.88 nm, corresponding to 1.11 THz at IGain=140  mA, IPhase=20  mA.

Fig. 8. Beating frequency (a) and corresponding peak wavelengths (b) as a function of the IDBR with fixed IGain=140  mA, IPhase=35  mA.

Fig. 9. Peak wavelengths as a function of IPhase with fixed IGain=140  mA, IDBR=10  mA.