100 GHz-spacing 8-channel light source integrated with gratings and LDs on PLC platform

We have successfully demonstrated a compact 100 GHz-spacing 8-channel light source integrated with ECLs, using PLC technology. We wrote UV gratings with the Bragg wavelength matched to the ITU grid by redesigning the phase mask. Moreover, we suppressed temperature-dependent mode hopping by using silicone techniques, and controlled the longitudinal mode wavelength by exposing the waveguide in the cavity to UV irradiation. These methods enabled us to form an 8-channel light source without temperature-dependent mode hopping in any of the channels. The oscillation wavelengths of the 8 channels matched the ITU grid with an accuracy of ±0.08 nm, and we obtained an optical power of more than 1.5 mW at an injection current of 80 mA for every channel. These results show that the 8 channel light source is promising with a view to realizing inexpensive DWDM systems.