Low-threshold inGaAsP ridge-waveguide laser fabricated by a new contacting system

A new type of index-guided laser, the bridge-contacted ridge-waveguide (BCRW) laser, is reported. Without the use of any sophisticated fabrication processes, CW threshold currents of 28 mA and quantum efficiencies of 60% are obtained for 3 ¿m-wide and 200 ¿m-long devices. In the last processing step the lateral index-guiding properties of this structure can be adjusted within a wide range. It is demonstrated that strong passive waveguiding results in both monomode emission and a narrow single-lobed far-field pattern, even for high injection currents.