Multiple quantum well structure, semiconductor laser and manufacturing method for multiple quantum well structure

A multiple quantum well structure between a p-type semiconductor and an n-type semiconductor in a semiconductor laser, the multiple quantum well structure comprising:

• a plurality of well layers;
• and
• a plurality of barrier layers having shorter composition wavelengths than the plurality of well layers,
• wherein at least one of the plurality of well layers, excluding a p-side well layer closest to the p-type semiconductor, has a quantum level wavelength shorter than a quantum level wavelength of the p-side well layer.

A manufacturing method for a multiple quantum well structure for a semiconductor laser, comprising:

• forming the multiple quantum well structure on an n-type InP substrate, the multiple quantum well structure including a plurality of InGaAsSb well layers and a plurality of InGaAsSb barrier layers having shorter composition wavelengths than the InGaAsSb well layers, by performing crystal growth to form the respective InGaAsSb well layers and the InGaAsSb barrier layers, alternately;
• and
• performing crystal growth of a p-type InP clad layer on the multiple quantum well structure,
• wherein:
• an amount of As supplied and an amount of Sb supplied when each of the plurality of InGaAsSb well layers is crystal-grown are equal, and
• an Sb content increases in order from an InGaAsSb well layer closest to the n-type InP substrate to an InGaAsSb well layer closest to the p-type InP clad layer.