16-WAVELENGTH GAIN-COUPLED DFB LASER ARRAY WITH FINE TUNABILITY

16-wavelength semiconductor laser array with fine wavelength tunabilit y is demonstrated, utilizing gain-coupled distributed feedback (DFB) l asers with different ridge waveguide widths. Besides the coarse tuning by the ridge widths, the fine post-fabrication tunability for individ ual lasers in the array is achieved with a Ti thin-film resistor integ rated on the chip. Due to the gain-coupling effect, 16 singlemode lasi ng wavelengths around 1.55 mu m in similar to 1 nm spacing are obtaine d simultaneously. An effective fine-tuning up to 1 nm is observed at a moderate heating power of 100 mW.