Patent ID: 6947652

Claim:
An optical waveguide comprising: a) a core having a refractive index n co and a radius r co ; b) an inner cladding laterally surrounding the core, the inner cladding having a refractive index n ic and an outer radius of r ic ; c) an outer cladding laterally surrounding the inner cladding, the outer cladding having a refractive index n oc ; d) wherein the core, inner cladding and outer cladding have a narrow depressed well configuration, wherein n co >n oc >n ic , with e) the range of the ratio of the inner, depressed-well clad radius, r ic , to core radius, r co , varying from about 2.4 to 3.0; f) a +Δ of about 0.0014 to 0.0021; g) a −Δ of about −0.0021 to −0.0034; and h) a Δ Tot of about 0.0043 to 0.0049, wherein the waveguide operates in two wavelength bands, wherein a first wavelength band is at about 1300 nm.