Multiple-wavelength membrane BH-DFB laser arrays

We realized multiple-wavelength laser arrays based on a membrane buried-heterostructure distributed-feedback (BH-DFB) structure fabricated by electron-beam lithography (EBL), CH₄/H₂ reactive-ion etching, and regrowth by organometallic vapor-phase epitaxy (OMVPE), and investigated their wavelength controllability using two different approaches, i.e., a modulation of the DFB grating period and that of the stripe width. Under optically pumped room-temperature continuous-wave (RT-CW) operation, a wavelength fluctuation for a fixed DFB grating period was found to be less than ±1.2 nm for all 75 samples prepared on the same wafer. A total wavelength span of 64 nm and an average channel spacing of 3.4 nm were obtained in the DFB period modulation range of 311.25 to 335.00 nm with 1.25-nm steps. An average channel spacing of 4.1 nm was also obtained in the stripe modulation range of 1.0-2.8 μm with 0.2-μm steps.