High power, singlemode InGaAs-GaAs-AlGaAs strained quantum well lasers with new current blocking scheme using GaAs layers grown by MBE at low substrate temperatures

Device results from laser diodes with a new current blocking scheme using low temperature (LT) GaAs grown by MBE at 200 degrees C are reported. The laser structure is grown by metal organic vapour phase epitaxy on channelled MBE-grown LT-GaAs. The LT-GaAs is shown to be effective in preserving the current blocking properties for InGaAs-GaAs-AlGaAs strained quantum well lasers. The CW laser threshold is 50 mA at RT (with a lasing wavelength of 980 nm) and far field patterns show fundamental modes (both lateral and transverse modes) even at an output power of 55 mW (per facet, uncoated). FWHMs of far field patterns parallel and perpendicular to the junction plane are 16 and 39 degrees at an output power of 55 mW, respectively.