Dual-band bend tolerant optical waveguide

1. 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.

2. The optical waveguide of claim 1 , wherein:

a) the depressed-well clad to core diameter ratio is about 2.7;

b) the +Δ is about 0.0019;

c) the −Δ is about −0.0028; and

d) the Δ Tot is about 0.0047.

3. The optical waveguide of claim 1 , wherein the optical waveguide is an optical fiber.

4. The optical waveguide of claim 1 , wherein the optical waveguide is a single-mode optical fiber, and wherein a second wavelength band is at about 1550 nm.

5. The optical waveguide of claim 1 , wherein the core has a diameter of about 10-12 micrometers.

6. The optical waveguide of claim 1 , having an operating wavelength range between about 1300 to 1550 nm and a second mode cutoff wavelength of less than 1300 nm.

7. The optical waveguide of claim 1 , having an operational mode field diameter between about 8.8 to 9.6 microns when measured at 1300 nm.

8. The optical waveguide of claim 1 , having an operational mode field diameter between about 9.6 to 11.2 microns when measured at 1550 nm.

9. The optical waveguide of claim 1 , having bend losses less than or equal to 0.05 dB when measured on a 0.635 cm 90 degree bend at 1300 nm and having bend losses less than or equal to 0.2 dB when measured on a 0.635 cm-90 degree bend at 1550 nm.

10. The optical waveguide of claim 1 having bend losses less than or equal to 0.2 dB when measured on a 0.635 cm 90 degree bend at 1550 nm.

11. The optical waveguide of claim 1 having bend losses less than or equal to 0.3 dB when measured on a 0.635 cm 90 degree bend at 1600 nm.

12. The optical waveguide of claim 1 , wherein the waveguide has a glass core and claddings, the waveguide further comprising a hard polymer permanently bonded to the outside surface of the glass waveguide.

13. The optical waveguide of claim 12 , wherein the hard polymer comprises a material having a Shore D hardness of at least 55.

14. The optical waveguide of claim 13 , wherein the hard polymer comprises a material having a Young's Modulus of from 50 kg/mm 2 to 250 kg/mm 2 at room temperature.

15. The optical waveguide of claim 1 , further comprising a soft polymer material coating the hard polymer, wherein the soft polymer materials comprises coatings selected from the group of Desolite 3471-3-14, Desolite 3471-1-152A, and Shin-Etsu OF-206.

16. The optical waveguide of claim 1 , wherein the inner cladding comprises one or more of the following fluorosilicate, borosilicate, phosphorus fluorosilicate, phosphorus borosilicate, germanium fluorosilicate or germanium borosilicate composition.

17. An optical device including the optical waveguide of claim 1 .