Selection-free WDM DFB lasers for STM16 applications

A selection-free DFB concept has been proposed and successfully demonstrated. By using only conventional manufacturing processes developed for the fabrication of DFB laser, a high SMR value of 43.5 dB @ 6 mW was obtained, with 0.19 W/A external facet efficiency as well as a 12 mA threshold current. The standard deviation of the emitted wavelength is as low as 0.11 nm, which underlines the spectral homogeneity of this approach. Under STM 16 transmission over 90 km of standard fiber, no floor is observed at 8% extinction ratio with a low system penalty of 1 dB. Moreover a good reproducibility is observed from laser to laser. These results demonstrate not only good performances of the structure under static and dynamic experiments but overall a very high uniformity of each characteristics. This demonstration is very encouraging, and open a new way for the fabrication of selection-free WDM lasers for STM 16 applications.