An Eight-Wavelength BH DFB Laser Array With Equivalent Phase Shifts for WDM Systems

In this letter, we report an eight-wavelength monolithically integrated buried heterostructure distributed feedback laser array with quarter-wave equivalent phase shifts. The laser array operating at 1.3 μm has a chip size of 2 mm × 250 μm. Lasing channel spacing is designed to be 800 GHz (~4.6 nm at 1.3 μm). The laser array exhibits accurate wavelength control and stable single mode lasing operation over a wide range of injection currents and different ambient temperatures. The measured linewidth of these lasers is 278 kHz at 65-mA bias current. In addition, the lasing wavelength of the whole laser array can be tuned continuously over 38.3 nm without mode hopping. The proposed method offers a practical approach of integrated laser array fabrication for wavelength-division multiplexing systems.