A semiconductor laser diode, the semiconductor laser diode comprising: a substrate, the substrate being formed from a first selected plurality of materials which is Gallium Arsenide (GaAs); an n-type semiconductor layer, the n-type semiconductor layer being formed from a plurality of materials selected from a second plurality of materials; a p-type semiconductor layer, the p-type semiconductor layer being formed from a plurality of materials selected from a third plurality of materials, the selected plurality of materials forming the p-type semiconductor layer being different from the selected plurality of materials forming the n-type semiconductor layer; and one or more quantum wells (208a, 208b), the one or more quantum wells (208a, 208b) being disposed between the n-type semiconductor layer and the p-type semiconductor layer, the one or more quantum wells (208a, 208b) being formed from a plurality of materials selected from a fourth plurality of materials, wherein: the n-type semiconductor layer and the p-type semiconductor layer form a waveguide for the laser light emitted in the one or more quantum wells (208a, 208b); the second selected plurality of materials has a conduction band offset that is smaller than a conduction band offset of the third selected plurality of materials and the third selected plurality of materials has a valence band offset that is smaller than a valence band offset of the second selected plurality of materials, the conduction band and the valence band offsets being calculated relative to the respective band energies of Gallium Arsenide (GaAs). a substrate, the substrate being formed from a first selected plurality of materials which is Gallium Arsenide (GaAs); an n-type semiconductor layer, the n-type semiconductor layer being formed from a plurality of materials selected from a second plurality of materials; a p-type semiconductor layer, the p-type semiconductor layer being formed from a plurality of materials selected from a third plurality of materials, the selected plurality of materials forming the p-type semiconductor layer being different from the selected plurality of materials forming the n-type semiconductor layer; and one or more quantum wells (208a, 208b), the one or more quantum wells (208a, 208b) being disposed between the n-type semiconductor layer and the p-type semiconductor layer, the one or more quantum wells (208a, 208b) being formed from a plurality of materials selected from a fourth plurality of materials, wherein: the n-type semiconductor layer and the p-type semiconductor layer form a waveguide for the laser light emitted in the one or more quantum wells (208a, 208b); the second selected plurality of materials has a conduction band offset that is smaller than a conduction band offset of the third selected plurality of materials and the third selected plurality of materials has a valence band offset that is smaller than a valence band offset of the second selected plurality of materials, the conduction band and the valence band offsets being calculated relative to the respective band energies of Gallium Arsenide (GaAs). the n-type semiconductor layer and the p-type semiconductor layer form a waveguide for the laser light emitted in the one or more quantum wells (208a, 208b); the second selected plurality of materials has a conduction band offset that is smaller than a conduction band offset of the third selected plurality of materials and the third selected plurality of materials has a valence band offset that is smaller than a valence band offset of the second selected plurality of materials, the conduction band and the valence band offsets being calculated relative to the respective band energies of Gallium Arsenide (GaAs).