A versatile, digital-alloy molecular beam epitaxy (MBE) technique is employ
ed to grow lattice-matched and strained AIGaInAs multiple-quantum well (MQW
) 1.58-mu m laser diodes on InP. A threshold current density as low as 510
A/cm(2) has been demonstrated for broad area lasers with 1% strained AIGaIn
As MQW's, which is the best MBE result in this material system. A single fa
cet pulsed power as high as 0.56 W is obtained. It is also found that the e
fficiency and internal loss of digital alloy AIGaInAs QW devices are compar
able to lasers grown by conventional MBE.