Patent ID: 6940639

Claim:
An intersubband (ISB) nonlinear optical device comprising: a cavity resonator including a ridge waveguide, said waveguide including a nonlinear mixing region and a core region, said mixing region and said core region being monolithically integrated within said waveguide, said core region including an active region comprising a multiplicity of repeat units, each repeat unit including a unipolar radiative transition (RT) region and a relaxation/injection (I/R) region adjacent thereto, said RT regions generating lasing light at at least one first center frequency via intersubband optical transitions in response to pumping energy applied thereto, and said nonlinear mixing region generating parametric light at at least one second center frequency, different from said first center frequency, in response to said lasing light, characterized in that said waveguide is configured so that (i) said lasing light is generated in a first transverse mode and said parametric light is generated in a second, different transverse mode, and (ii) the effective-refractive-index-versus-ridge-width characteristics of said first and second modes intersect one another at a phase matching width, and said ridge width is essentially equal to said phase matching width.