Multi-mode pumped ase source using phosphate and tellurite glasses

• US 20040109225A1
• Filed: 12/06/2002
• Published: 06/10/2004
• Est. Priority Date: 12/06/2002
• Status: Abandoned Application

• Current Assignee: NP Photonics Incorporated
• Original Assignee: NP Photonics Incorporated
• Inventors: Mendes, Sergio Brito, Hu, Yongdan, Kaneda, Yushi, Jiang, Shibin, Hocde, Sandrine
• Application Number:
  US10/313,287
• Publication Number:
  US 20040109225A1
• Time in Patent Office: Days
• US Class Current: 359/341.1
• CPC Class Codes: H01S 3/06716 Fibre compositions per se C03C13/04or doping with active elements lasing materials in general H01S3/14
• CPC Class Codes: H01S 3/06795 with superfluorescent emission, e.g. amplified spontaneous emission sources for fibre laser gyrometers fibre laser gyrometers per se G01C19/72
• CPC Class Codes: H01S 3/1608 erbium
• CPC Class Codes: H01S 3/1618 ytterbium
• CPC Class Codes: H01S 3/175 phosphate glass
• CPC Class Codes: H01S 3/177 telluride glass

Abstract

A compact, high-power, low-cost broadband ASE source is achieved by multi-mode pumping a highly doped multi-component glass fiber in standard ASE source configurations. The multi-mode pump is coupled into and propagates in the fiber cladding exciting the rare-earth dopant ions (Er,Yb) in the fiber core. The multi-component glass includes a network former selected from either phosphate (P₂O₅) or tellurite (TeO₂) and is doped with at least 0.25 weight percent rare-earth dopants. The high concentrations of dopants supported by these glasses absorbs the multi-mode pump in a short length, less than 100 cm, and provides high saturated output powers.

Claims

1. An amplified spontaneous emission (ASE) source, comprising:

An optical fiber having a core, at least one inner cladding and an outer clad, said fiber formed from a multi-component glass host of either phosphate or tellurite with said core doped with at least 0.25 weight percent of a rare-earth dopant; and

A multi-mode pump source that injects optical energy into the fiber'"'"'s inner cladding to excite the rare-earth dopants in the core and produce stimulated emission of a broadband optical signal.

2. The ASE source of claim 1, wherein said fiber is formed from phosphate (P₂O₅) of 50 to 70 mole percent;

MO of 0 to 25 weight percent (BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof), A₂O₃ of 2 to 20 weight percent (WO₃, Y₂O₃, La₂O₃, Al₂O₃, B₂O₃ and mixtures thereof), and doped with 1.5 to 5 weight percent erbium and 0 to 12 weight percent ytterbium.

3. The ASE source of claim 2, wherein said fiber is formed from phosphate (P₂O₅) of 55 to 70 mole percent;

MO of 10 to 25 weight percent (BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof), A₂O₃ of 10 to 20 weight percent (WO₃, Y₂O₃, La₂O₃, Al₂O₃, B₂O₃ and mixtures thereof), and doped with 2 to 5 weight percent erbium and 0 to 12 weight percent ytterbium.

4. The ASE source of claim 1, wherein said fiber is formed from tellurite (TeO₂) from 50 to 70 mole percent, A₂O₃ from 10 to 40 mole percent including B₂O₃ from 5 to 22 mole percent (Al2O₃, Y₂O₃, B₂O₃ and mixtures thereof), a glass network modifier R₂O from 5 to 25 mole percent (Li₂O, Na₂O, K₂O and mixtures thereof), a glass network modifier MO from 0 to 15 mole percent (MgO, CaO, BaO, ZnO and mixtures thereof), GeO₂ from 0 to 7 mole percent and rare-earth dopant L₂O₃ from 0.25 to 10 weight percent (Er₂O₃, Yb₂O₃ and mixtures thereof).

5. The ASE source of claim 4, wherein said fiber is formed from tellurite (TeO₂) from 55 to 65 mole percent, A₂O₃ from 20 to 35 mole percent including B₂O₃ from 10 to 20 mole percent and Al₂O₃ from 10 to 15 mole percent, a glass network modifier Na₂O from 10 to 20 mole percent, a glass network modifier MO from 0 to 10 mole percent (MgO, CaO, BaO, ZnO and mixtures thereof), GeO₂ from 0 to 5 mole percent and rare-earth dopant L₂O₃ from 0.25 to 6 weight percent (Er₂O₃, Yb₂O₃ and mixtures thereof).

6. The ASE source of claim 1, wherein the fiber has a length of 10-100 cm.

7. The ASE source of claim 1, further comprising:

A passive fiber having a core and an inner cladding with at least one flat surface, said passive fiber being optically coupled to the optical fiber; and

A total internal reflection (TIR) coupler in optical contact with the inner cladding'"'"'s flat surface for a length L and having a reflecting surface that forms an angle of taper α

with said inner cladding, said TIR coupler being effective to reflect the pump'"'"'s optical energy at a preselected angle of incidence θ

_inc for the principal ray and satisfy a TIR condition at its reflecting surface for folding the pump into the passive fiber, wherein said pump beam also satisfies a TIR condition for guiding pump light inside the inner cladding where it is coupled to the optical fiber.

8. The ASE source of claim 1, wherein the optical fiber comprises at least two inner claddings with successively lower indices of refraction.

9. The ASE source of claim 1, further comprising a second optical fiber that is optically pumped by the same multi-mode pump source.

10. An amplified spontaneous emission (ASE) source, comprising:

An optical fiber having a core, at least one inner cladding and an outer clad, said fiber formed from phosphate (P₂O₅) of 50 to 70 mole percent;

MO of 0 to 25 weight percent (BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof), A₂O₃ of 2 to 20 weight percent (WO₃, Y₂O₃, La₂O₃, Al₂O₃, B₂O₃ and mixtures thereof), and doped with 1.5 to 5 weight percent erbium and 0 to 12 weight percent ytterbium; and

A multi-mode pump source which injects optical energy into the fiber'"'"'s inner cladding to excite the rare-earth dopants in the core and produce stimulated emission of a broadband optical signal.

11. The ASE source of claim 10, wherein said fiber is formed from phosphate (P₂O₅) of 55 to 70 mole percent;

MO of 10 to 25 weight percent (BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof), A₂O₃ of 10 to 20 weight percent (WO₃, Y₂O₃, La₂O₃, Al₂O₃, B₂O₃ and mixtures thereof), and doped with 2 to 5 weight percent erbium and 0 to 12 weight percent ytterbium.

12. The ASE source of claim 11, wherein said fiber has a length of 10-50 cm.

13. An amplified spontaneous emission (ASE) source, comprising:

An optical fiber having a core, at least one inner cladding and an outer clad, said fiber formed from tellurite (TeO₂) from 50 to 70 mole percent, A₂O₃ from 10 to 40 mole percent including B₂O₃ from 5 to 22 mole percent (Al₂O₃, Y₂O₃, B₂O₃ and mixtures thereof), a glass network modifier R₂O from 5 to 25 mole percent (Li₂O, Na₂O, K₂O and mixtures thereof), a glass network modifier MO from 0 to 15 mole percent (MgO, CaO, BaO, ZnO and mixtures thereof), GeO₂ from 0 to 7 mole percent and rare-earth dopant L₂O₃ from 0.25 to 10 weight percent (Er₂O₃, Yb₂O₃ and mixtures thereof); and

A multi-mode pump source which injects optical energy into the fiber'"'"'s inner cladding to excite the rare-earth dopants in the core and produce stimulated emission of a broadband optical signal.

14. The ASE source of claim 13, wherein said fiber is formed from tellurite (TeO₂) from 55 to 65 mole percent, A₂O₃ from 20 to 35 mole percent including B₂O₃ from 10 to 20 mole percent and Al₂O₃ from 10 to 15 mole percent, a glass network modifier Na₂O from 10 to 20 mole percent, a glass network modifier MO from 0 to 10 mole percent (MgO, CaO, BaO, ZnO and mixtures thereof), GeO₂ from 0 to 5 mole percent and rare-earth dopant L₂O₃ from 0.25 to 6 weight percent (Er₂O₃, Yb₂O₃ and mixtures thereof).

15. The ASE source of claim 14, wherein the rare-earth dopant comprises 0.25 to 3 weight percent Er₂O₃ and 0.25 to 3 weight percent Yb₂O₃.

16. The ASE source of claim 14, wherein said fiber has a length of 10-100 cm.

17. An amplified spontaneous emission (ASE) source, comprising:

A first optical fiber having a core, at least one inner cladding and an outer clad, said first fiber formed from a phosphate(P₂O₅) glass host with said core doped with at least 0.25 weight percent of a rare-earth dopant;

A second optical fiber having a core, at least one inner cladding and an outer clad, said second fiber formed from a tellurite (TeO₂) glass host with said core doped with at least 0.25 weight percent of a rare-earth dopant; and

A multi-mode pump source which injects optical energy into the fibers'"'"' inner claddings to excite the rare-earth dopants in the cores and produce stimulated emission of a broadband optical signal.

18. The ASE source of claim 17, wherein said first optical fiber is formed from phosphate (P₂O₅) of 50 to 70 mole percent;

MO of 0 to 25 weight percent (BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof), A₂O₃ of 2 to 20 weight percent (WO₃, Y₂O₃, La₂O₃, Al₂O₃, B₂O₃ and mixtures thereof), and doped with 1.5 to 5 weight percent erbium and 0 to 12 weight percent ytterbium and said second optical fiber is formed from tellurite (TeO₂) from 50 to 70 mole percent, A₂O₃ from 10 to 40 mole percent including B₂O₃ from 5 to 22 mole percent (Al₂O₃, Y₂O₃, B₂O₃ and mixtures thereof), a glass network modifier R₂O from 5 to 25 mole percent (Li₂O, Na₂O, K₂O and mixtures thereof), a glass network modifier MO from 0 to 15 mole percent (MgO, CaO, BaO, ZnO and mixtures thereof), GeO₂ from 0 to 7 mole percent and rare-earth dopant L₂O₃ from 0.25 to 10 weight percent (Er₂O₃, Yb₂O₃ and mixtures thereof).

19. An ASE source of claim 17, wherein said first optical fiber is formed from phosphate (P₂O₅) of 55 to 70 mole percent;

MO of 10 to 25 weight percent (BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof), A₂O₃ of 10 to 20 weight percent (WO₃, Y₂O₃, La₂O₃, Al₂O₃, B₂O₃ and mixtures thereof), and doped with 2 to 5 weight percent erbium and 0 to 12 weight percent ytterbium and said second optical fiber is formed from from tellurite (TeO₂) from 55 to 65 mole percent, A₂O₃ from 20 to 35 mole percent including B₂O₃ from 10 to 20 mole percent and Al₂O₃ from 10 to 15 mole percent, a glass network modifier Na₂O from 10 to 20 mole percent, a glass network modifier MO from 0 to 10 mole percent (MgO, CaO, BaO, ZnO and mixtures thereof), GeO₂ from 0 to 5 mole percent and rare-earth dopant L₂O₃ from 0.25 to 6 weight percent (Er₂O₃, Yb₂O₃ and mixtures thereof).

20. The ASE source of claim 17, further comprising an isolator or filter between said first and second optical fibers.

21. An amplified spontaneous emission (ASE) source, comprising:

An outer cladding;

An inner cladding;

a plurality of core elements formed in the inner cladding, each said core element formed from a multi-component glass host of either phosphate or tellurite and doped with at least 0.25 weight percent of a rare-earth dopant; and

A multi-mode pump source which injects optical energy that is confined to the inner cladding to excite the rare-earth dopants in the core elements and produce stimulated emission of a plurality of broadband optical signals

22. The ASE source of claim 21, wherein the multi-mode pump source is positioned to inject optical energy transverse to the orientation of the core elements.

23. The ASE source of claim 21, wherein the multi-mode pump source is positioned to inject optical energy into the ends of the core elements.

24. The ASE source of claim 21, wherein at least one core element is formed from a phosphate glass host and at least one core element is formed from a tellurite glass host.

25. The ASE source of claim 21, wherein core elements formed from a phosphate glass host include phosphate (P₂O₅) of 50 to 70 mole percent;

MO of 0 to 25 weight percent (BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof), A₂O₃ of 2 to 20 weight percent (WO₃, Y₂O₃, La₂O₃, Al₂O₃, B₂O₃ and mixtures thereof), and doped with 1.5 to 5 weight percent erbium and 0 to 12 weight percent ytterbium and core elements formed from a tellurite glass host include tellurite (TeO₂) from 50 to 70 mole percent, A₂O₃ from 10 to 40 mole percent including B₂O₃ from 5 to 22 mole percent (Al₂O₃, Y₂O₃, B₂O₃ and mixtures thereof), a glass network modifier R₂O from 5 to 25 mole percent (Li₂O, Na₂O, K₂O and mixtures thereof), a glass network modifier MO from 0 to 15 mole percent (MgO, CaO, BaO, ZnO and mixtures thereof), GeO₂ from 0 to 7 mole percent and rare-earth dopant L₂O₃ from 0.25 to 10 weight percent (Er₂O₃, Yb₂O₃ and mixtures thereof).

26. An amplified spontaneous emission (ASE) source, comprising:

A multi-mode pump source that emits a pump beam;

A passive fiber having a core and an inner cladding with at least one flat surface; and

A total internal reflection (TIR) coupler in optical contact with the inner cladding'"'"'s flat surface for a length L and having a reflecting surface that forms an angle of taper α

with said inner cladding, said TIR coupler being effective to reflect the pump beam at a preselected angle of incidence θ

_inc for the principal ray and satisfy a TIR condition at its reflecting surface for folding the pump beam into the passive fiber, wherein said pump beam also satisfies a TIR condition for guiding pump light inside the inner cladding; and

An active fiber having a core, at least one inner cladding and an outer clad, said fiber formed from a multi-component glass host of either phosphate or tellurite with said core doped with at least 0.25 weight percent of a rare-earth dopant, said active fiber being optically coupled to said passive fiber to receive said pump beam, which excites the rare-earth dopants in the core to produce stimulated emission of a broadband optical signal.

27. The ASE source of claim 26, wherein said fiber is formed from phosphate (P₂O₅) of 50 to 70 mole percent;

MO of 0 to 25 weight percent (BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof), A₂O₃ of 2 to 20 weight percent (WO₃, Y₂O₃, La₂O₃, Al₂O₃, B₂O₃ and mixtures thereof), and doped with 1.5 to 5 weight percent erbium and 0 to 12 weight percent ytterbium.

28. The ASE source of claim 27, wherein said fiber is formed from phosphate (P₂O₅) of 55 to 70 mole percent;

MO of 10 to 25 weight percent (BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof), A₂O₃ of 10 to 20 weight percent (WO₃, Y₂O₃, La₂O₃, Al₂O₃, B₂O₃ and mixtures thereof), and doped with 2 to 5 weight percent erbium and 0 to 12 weight percent ytterbium.

29. The ASE source of claim 26, wherein said fiber is formed from tellurite (TeO₂) from 50 to 70 mole percent, A₂O₃ from 10 to 40 mole percent including B₂O₃ from 5 to 22 mole percent (Al₂O₃, Y₂O₃, B₂O₃ and mixtures thereof), a glass network modifier R₂O from 5 to 25 mole percent (Li₂O, Na₂O, K₂O and mixtures thereof), a glass network modifier MO from 0 to 15 mole percent (MgO, CaO, BaO, ZnO and mixtures thereof), GeO₂ from 0 to 7 mole percent and rare-earth dopant L₂O₃ from 0.25 to 10 weight percent (Er₂O₃, Yb₂O₃ and mixtures thereof).

30. The ASE source of claim 29, wherein said fiber is formed from tellurite (TeO₂) from 55 to 65 mole percent, A₂O₃ from 20 to 35 mole percent including B₂O₃ from 10 to 20 mole percent and Al₂O₃ from 10 to 15 mole percent, a glass network modifier Na₂O from 10 to 20 mole percent, a glass network modifier MO from 0 to 10 mole percent (MgO, CaO, BaO, ZnO and mixtures thereof), GeO₂ from 0 to 5 mole percent and rare-earth dopant L₂O₃ from 0.25 to 6 weight percent (Er₂O₃, Yb₂O₃ and mixtures thereof).