Threshold current operation of 2.5 mA was achieved for 1.5-µm multiple-quantum-well distributed feedback (MQW-DFB) laser diodes (LD’s) with semi-insulating current blocking layers entirely grown by metal organic vapor phase epitaxy (MOVPE). Such low threshold current was attained by reduced leakage current and reduced mirror loss in the laser structure. The required bias current for achieving several gigahertz bandwidth was markedly reduced due to the enhanced differential gain and low threshold current. Due to the reduced lasing delay time in such low threshold LD's, up to 5-GHz zero-bias current modulation, with a clear eye opening, was successfully demonstrated.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics