Quantum well laser with an extremely large active layer width to optical confinement factor ratio for high-energy single picosecond pulse generation by gain switching

It is theoretically shown that gain switching quantum well AlGaAs/InGaAs laser with a very large ratio of active layer thickness to optical confinement factor (∼8 µm) can result in single, high-energy (>>1 nJ) short (∼100 ps) single optical pulses at wavelengths ∼1 µm. Calculations predict that high electrical-to-optical conversion efficiency can be achieved in such structures, which require an injection current pulse of a modest amplitude of ∼10 A and a duration of 1.5–2 ns. A narrow asymmetric waveguide design is proposed as a way of implementing such a structure while maintaining good far-field properties of the single emitted mode