Ridge-waveguide buried-heterostructure laser and method of fabrication

A method of forming a laser, comprising:

• providing a ridge-waveguide laser structure with a region of active lasing material buried within a charge carrier confining material, said confining material including an upstanding ridge, said ridge defining a refractive index differential between said charge confining material within the lateral boundaries of said ridge and the charge carrier confining material lateral to said ridge, said ridge and said refractive index differential establishing a lateral optical confinement for said region of active lasing material, said active region extending beyond the lateral bounds of said ridge, and
• compositionally disordering the portions of said active region which extend generally beyond the lateral bounds of said ridge by electric field-accelerated-ion implantation into said lateral active region portions, and simultaneously with said implantation heating said laser structure to an ion annealing temperature less than the threshold for temperature degradation of the material from which said laser structure is formed, said annealing temperature also being substantially less than the temperature necessary to comparably anneal said material in the absence of said simultaneous ion implantation, to give said lateral active region portions a larger bandgap and lower refractive index than the remainder of said active region which is generally aligned substantially with the lateral bounds of said ridge, and thereby provide lateral charge carrier and optical confinement for said remaining active region.