MICROSTRUCTURED OPTICAL FIBERS AND MANUFACTURING METHODS THEREOF

• US 20090201953A1
• Filed: 05/03/2006
• Published: 08/13/2009
• Est. Priority Date: 05/03/2005
• Status: Active Grant

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona BD of REG On Behalf of The University AZ
• Inventors: Temyanko, Valery, Peyghambarian, Nasser, Schulzgen, Axel
• Granted Patent: US 8,731,356 B2
• Time in Patent Office: Days
• US Class Current: 372/6
• CPC Class Codes: C03B 2201/70 containing phosphorus
• CPC Class Codes: C03B 2201/82 Fluoride glasses, e.g. ZBLAN glass
• CPC Class Codes: C03B 2201/86 Chalcogenide glasses, i.e. S, Se or Te glasses
• CPC Class Codes: C03B 2203/14 Non-solid, i.e. hollow products, e.g. hollow clad or with core-clad interface
• CPC Class Codes: C03B 2203/34 Plural core other than bundles, e.g. double core
• CPC Class Codes: C03B 2203/42 Photonic crystal fibres, e.g. fibres using the photonic bandgap PBG effect, microstructured or holey optical fibres
• CPC Class Codes: C03B 37/0122 for making preforms of photonic crystal, microstructured or holey optical fibres
• CPC Class Codes: G02B 6/02333 Core having higher refractive index than cladding, e.g. solid core, effective index guiding
• CPC Class Codes: G02B 6/02338 Structured core, e.g. core contains more than one material, non-constant refractive index distribution in core, asymmetric or non-circular elements in core unit, multiple cores, insertions between core and clad
• CPC Class Codes: G02B 6/02352 Complex periodic lattices or multiple interpenetrating periodic lattices, e.g. unit cell having more than two materials, partially internally coated holes, for multiple bandgaps
• CPC Class Codes: H01S 3/06729 Peculiar transverse fibre profile
• CPC Class Codes: H01S 3/06737 Fibre having multiple non-coaxial cores, e.g. multiple active cores or separate cores for pump and gain
• CPC Class Codes: H01S 3/06741 Photonic crystal fibre, i.e. the fibre having a photonic bandgap
• CPC Class Codes: H01S 3/094003 the pumped medium being a fibre

Abstract

Optical devices and a method for manufacturing these devices. One optical device includes a core region having a first medium of a first refractive index n1, and includes a cladding region exterior to the core region. The cladding region includes a second medium having a second refractive index n2 higher than the first refractive index n1. The cladding region further includes a third medium having a third refractive index n3 lower than the first refractive index n1. The third medium is dispersed in the second medium to form a plurality of microstructures in the cladding region. Another optical device includes a plurality of core regions including at least one core having a doped first medium, and includes a cladding region exterior to the plurality of core regions. The core regions and the cladding region include a phosphate glass.

Claims

1. A method for manufacturing an optical device, comprising:

providing a plurality of first materials M1 having a first set of characteristic properties;

providing a plurality of second materials M2 having a second set of characteristic properties different from the first set;

making first preforms from materials M1 and M2;

drawing the first preforms into a first regular shape to form first unit cells;

providing a plurality of third materials M3 having a third set of characteristic properties;

providing a plurality of forth materials M4 having a fourth set of characteristic properties different from the third set;

making second preforms from materials M3 and M4, said second preforms having an outer shape of the first preforms;

drawing the second preforms into the same regular shape and size as the first unit cells to form second unit cells;

providing a plurality of fifth materials M5 having a fifth set of characteristic properties;

making a tube from M5;

forming a stack having a predetermined arrangement from multiple ones of the first and second unit cells;

inserting the stack into said tube made from M5; and

drawing the stack into a drawn unit that is configured to guide light in at least one region including the material M1.

2. The method of claim 1, further comprising:

providing, for at least one of the first, second, third, fourth, and fifth materials, at least one of a glass and a polymer.

3. The method of claim 1, wherein the making first preforms comprises:

forming at least one of the first preforms by inserting a rod made from M1 into a interior region of at least one of a tube, a hexagon, a square, a rectangle, or a triangle made from M2.

4. The method of claim 1, wherein the drawing the first preforms comprises:

producing for at least one of the first unit cells at least one of a circular, hexagonal, square, rectangular, triangular unit cell.

5. The method of claim 1, wherein the making second preforms comprises:

forming the second preform by inserting a rod made from M3 into a interior region of at least one of a tube, a hexagon, a square, a rectangle, or a triangle made from M4

6. The method of claim 1, wherein the drawing the second preforms comprises:

producing for at least one of the second unit cells at least one of a circular, hexagonal, square, rectangular, or a triangular unit cell.

7. The method of claim 1, wherein the forming a stack comprises:

producing for the predetermined arrangement at least one of a periodic structure or a non-periodic structure.

8. The method of claim 7, further comprising:

producing for the periodic arrangement at least one of a triangular array, a circular array, a square array, and a rectangular array.

9. The method of claim 1, wherein the making the second preforms comprises:

forming the second unit cells with the material M3 having a refractive index refractive less than 2.0.

10. The method of claim 9, wherein the forming the second unit cells comprises:

producing in the second unit cells an air core.

11. The method of claim 1, wherein the forming a stack comprises:

placing a solid one of the first unit cells in a center of the stack to form a solid core in the drawn unit.

12. The method of claim 11, wherein the placing a solid one of the first glass preforms in the center comprises:

placing a doped solid glass unit cell in the center.

13. The method of claim 1, wherein the forming a stack comprises:

placing the first and second unit cells in the stack in a predetermined order so as to form a stepped refractive index structure in the drawn unit, the stepped refractive index structure having a negative index change (n2−

n4) between the materials M2 and M4 that ranges from −

10<sup>−

4</sup> to −

10<sup>−

3</sup>.

14. The method of claim 1, wherein the forming a stack comprises:

placing a plurality of solid ones of the first glass unit cells in a vicinity of the center of the stack to form a plurality of solid cores in the drawn unit.

15. The method of claim 14, wherein the placing a plurality of the solid cores comprises:

placing doped solid glass unit cells in the vicinity of the center.

16. The method of claim 1, further comprising:

forming reflection coatings on ends of the drawn unit.

17. The method of claim 16, further comprising:

forming a trench in a substrate;

disposing the drawn unit in the trench;

forming a diffraction grating on a surface of the substrate adjacent the trench.

18. The method of claim 1, further comprising:

attaching passive fiber sections to the drawn unit; and

forming reflection coatings on ends of the passive fiber sections.

19. The method of claim 1, wherein the drawing the stack comprises:

producing a core region having a first medium of a first refractive index n1, and

producing a cladding region exterior to the core region, including a fourth medium having a forth refractive index n4 higher than the first refractive index n1,

wherein the cladding region includes a third medium having a third refractive index n3 lower than the first refractive index n1, and the third medium is dispersed in the second medium to form a plurality of microstructures in the cladding region.

20. The method of claim 1, wherein the drawing of the stack comprises:

producing a plurality of core regions including at least one core having a doped first medium; and

producing a cladding region exterior to the plurality of core regions,

wherein the core regions and the cladding region includes a phosphate glass.

21. A method for manufacturing an optical device formed of a plurality of first materials M1, second materials M2, third materials M3, fourth materials M4, and fifth materials M5 having respective first, second, third, fourth and fifth sets of characteristic properties, wherein the second set of characteristic properties of M2 is different from the first set of characteristic properties of M1, the fourth set of characteristic properties of M4 is different from that of the third set of characteristic properties of M3, said method comprising:

obtaining first unit cells formed of first preforms formed of materials M1 and M2 drawn into a first regular shape;

obtaining second unit cells formed of second preforms formed of materials M3 and M4 drawn into the same regular shape and size as the first unit cells;

obtaining a tube formed of M5;

forming a stack having a predetermined arrangement from multiple ones of the first and second unit cells;

inserting the stack into said tube made from M5; and

drawing the stack into a drawn unit that is configured to guide light in at least one region including the material M1.

22. An optical device comprising:

a core region having a first medium of a first refractive index n1;

a cladding region exterior to the core region, including a second medium having a second refractive index n2 higher than the first refractive index n1; and

said cladding region including a third medium having a third refractive index n3 lower than the first refractive index n1, said third medium dispersed in the second medium to form a plurality of microstructures in the cladding region.

23. The device of claim 22, wherein the cladding region and the core region comprise an optical fiber for transmission of light along a length of the fiber.

24. The device of claim 22, wherein the plurality of microstructures comprises a periodic array.

25. The device of claim 24, wherein the periodic array comprises at least one of a triangular array, a circular array, a square array, and a rectangular array.

26. The device of claim 22, wherein the third refractive index n3 is less than 2.0.

27. The device of claim 22, wherein the third medium comprises at least one of a polymer, liquid, and air.

28. The device of claim 22, wherein the cladding region and the core region comprise a stepped refractive index structure having a negative index change (n1−

n2) between the first medium and the second medium that ranges from −

10<sup>−

4</sup> to −

10<sup>−

3</sup>.

29. The device of claim 22, wherein at least one of the first, the second, and the third medium comprises at least one of a chalcogenide glass, a phosphate glass, and a fluoride glass.

30. The device of claim 22, wherein the cladding region and the core region comprise an optical fiber having a core area between 200 μ

m² and 4000 μ

m².

31. The device of claim 22, wherein the core region further comprises:

an absorption medium comprising a dopant configured to absorb incident radiation and generate photons through emission by dopant ions.

32. The device of claim 31, wherein the dopant comprises at least one of the rare earth elements, Er, Yb, Nd, Ho, and Pr, or metals such as Fe and Cr.

33. The device of claim 31, wherein the dopant comprises at least two of the rare earth elements, Er, Yb, Nd, Ho, and Pr, or metals such as Fe and Cr.

34. The device of claim 31, wherein the dopant comprises a concentration of at least 10²⁰ cm³.

35. The device of claim 22, wherein the cladding region and the core region comprise a laser, and further comprising:

an optical pumping device configured to irradiate an end of the laser.

36. The device of claim 22, wherein the cladding region and the core region comprise a laser, and further comprising:

an optical pumping device configured to irradiate a longitudinal side of the laser.

37. The device of claim 22, wherein the cladding region and the core region comprise a laser, and further comprising:

reflection coatings on ends of the laser, configured to transmit pumping light and partially reflect laser light from the interior of the laser.

38. The device of claim 22, wherein the cladding region and the core region comprise a laser, and further comprising:

a diffraction grating on an output end of the laser configured to partially reflect laser light from the interior of the laser.

39. The device of claim 22, wherein the cladding region and the core region comprise a laser, and further comprising:

a passive fiber coupled to the cladding region and the core region; and

reflection coatings on ends of the passive fiber, configured to transmit pumping light and partially reflect laser light from the interior of the laser.

40. An optical device comprising:

a plurality of core regions including at least one core having a doped first medium;

a cladding region exterior to the plurality of core regions; and

said core regions and said cladding region including a phosphate glass.

41. The device of claim 40, wherein:

the plurality of core regions further comprises an undoped first medium of a first refractive index n1; and

the cladding region includes a second medium having a second refractive index n2 higher than the first refractive index n1;

said cladding region further includes a third medium having a third refractive index n3 lower than the first refractive index n1; and

said third medium dispersed in the second medium to form a plurality of microstructures in the cladding region.

42. The device of claim 40, wherein:

the plurality of core regions further comprises an undoped first medium of a first refractive index n1; and

the cladding region includes a second medium having a second refractive index n2 lower than the first refractive index n1.