Spot-size expanded high efficiency 1.3 /spl mu/m MQW laser diodes with laterally tapered active stripe

A large spot-size laser diode (LD) with tapered active stripe has been realized. The threshold current and the slope efficiency were 14 mA and 0.43 W/A, respectively at 85/spl deg/C. These characteristics are comparable to those of conventional straight stripe LDs. The full width at half maximum (FWHM) of lateral and vertical far field patterns (FFPs) were 14/spl deg/ and 16/spl deg/, respectively. The maximum coupling efficiency of the tapered LD to a 10 /spl mu/m /spl phi/-core single mode fiber was -6.2 dB and horizontal 1 dB-down tolerance was /spl plusmn/2.0 /spl mu/m.