Optoelectronic device with enhanced lateral leakage of high order transverse optical modes into alloy-intermixed regions and method of making same

An optoelectronic device comprising

• a) a multilayer structure;
• b) a core region in the lateral plane;
• wherein said core region has a first vertical profile of the refractive index,
• wherein a set of optical modes having a first vertical profile of the optical field are formed in said core region,
• wherein said set of optical modes contains a fundamental transverse optical mode and at least one high-order transverse optical mode;
• and
• c) a periphery region in the lateral plane,
• wherein said periphery region is an adjacent region contiguous in the lateral plane to said core region,
• wherein said periphery region further comprises
• chemically transformed region,
• wherein said chemically transformed region is bounded by a bottom boundary and a top boundary,
• wherein said chemically transformed region is formed by a process of selective chemical transformation,
• wherein said process of selective chemical transformation changes the chemical profile in the vertical direction,
• wherein said selective chemical transformation in said chemically transformed region results in a change of the refractive index profile in said chemically transformed region such that said periphery region has a second vertical profile of the refractive index distinct from said first vertical profile of the refractive index,
• wherein a continuum spectrum of optical modes having at least one second vertical profile of the optical field is formed in said periphery region, and
• wherein at least one high-order transverse optical mode formed in said core region has a wavelength at resonance with the wavelength of at least one mode of said continuum spectrum of optical modes in said periphery region, and
• wherein said first vertical profile of the optical field and said second vertical profile of the optical field have an non-zero overlap integral, and
• wherein the lateral leakage losses of said at least one high-order transverse optical mode formed in said core region is larger than the lateral leakage losses of said fundamental transverse optical mode formed in said core region.