Fig. 1. (a) Schematic of the SBG structure; (b) the calculated reflection and transmission spectrum of each section and schematic of different operating wavelength positions.

Fig. 2. Small signal intensity modulation responses for different positions at (a) the left falling flank; (b) the right falling flank when I₁ is 100 mA.

Fig. 3. (a) Epitaxial structure of the chip (materials used are labeled in the diagram); (b) physical diagram of TS-DFB laser chip array.

Fig. 4. (a) light-current (LI) curves of TS-DFB laser at room temperature; (b) LI curves of TS-DFB laser at different temperatures.

Fig. 5. (a) Spectra of the eight-channel TS-DFB laser array when I₁ = 100 mA and I₂ = 25 mA; (b) linear fit for the lasing wavelength of each channel and wavelength residuals.

Fig. 6. Spectra of the laser (a) at different currents I₁ when I₂ = 25 mA; (b) at different currents I₂ when I₁ = 100 mA; measured lasing wavelength and SMSR when (c) I₂ is fixed at 25 mA and I₁ varies from 20 to 100 mA; (d) I₁ is fixed at 100 mA and I₂ varies from 0 to 25 mA.

Fig. 7. (a) Amplified spontaneous emission spectrum around threshold; (b) spectrum when injection current is 100 mA.

Fig. 8. (a) Lasing spectra at different temperatures when I₁ = 100 mA and I₂ = 25 mA; (b) corresponding lasing wavelengths and SMSRs.

Fig. 9. Spectra of the laser at different injection currents I₂ for I₁ = 110 mA when the laser is under RF signal modulation.

Fig. 10. Frequency response curves at different currents.

Fig. 11. Change in bandwidth when the lasing wavelength falls on the right falling edge of the reflection spectrum. (a) Fixed I₂ = 0 mA constantly increasing I₁; (b) fixed I₁ = 110 mA constantly increasing I₂.

Fig. 12. RIN measured by (a) varying the injection current I₁ when I₂ = 0 mA; (b) varying the injection current I₂ when I₁ = 100 mA.

Fig. 13. 1-dB compression point curves.

Fig. 14. (a) Small-signal modulation response after a time-delay fiber; (b) example of chirp parameter calculation; (c) chirp parameters for different injection currents.