Wavelength tuning characteristics of tunable twin-guide lasers with improved current-injection structures

Abstract
Tunable twin-guide distributed feedback (TTG-DFB) lasers are fabricated by the all-metalorganic vapor phase epitaxy (MOVPE) process. A very wide continuous tuning range (4.9 nm/25 mA) with single-mode operation is obtained by improving the efficiency of current-injection into the modulation layer. The side-mode suppression ratio (SMSR) is larger than 20 dB in the tuning range up to 4.3 nm.The threshold current is 16 mA and maximum output power is 5 mW.