Apparatus and methods using hollow-core fiber tapers

• US 8,244,086 B2
• Filed: 07/21/2011
• Issued: 08/14/2012
• Est. Priority Date: 07/25/2006
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Digonnet, Michel J. F., Ozcan, Aydogan
• Primary Examiner(s): Peng, Charlie
• Assistant Examiner(s): Radkowski, Peter
• Application Number:
  US13/187,930
• Publication Number:
  US 20110273712A1
• Time in Patent Office: 390 Days
• Field of Search: 385/43, 359/333
• US Class Current: 385/43
• CPC Class Codes: G02B 6/02052 comprising optical elements other than gratings, e.g. filters comprising gratings G02B6/02057
• CPC Class Codes: G02B 6/02304 Core having lower refractive index than cladding, e.g. air filled, hollow core
• CPC Class Codes: G02B 6/02328 Hollow or gas filled core
• CPC Class Codes: G02B 6/02347 Longitudinal structures arranged to form a regular periodic lattice, e.g. triangular, square, honeycomb unit cell repeated throughout cladding
• CPC Class Codes: G02B 6/02376 Longitudinal variation along fibre axis direction, e.g. tapered holes
• CPC Class Codes: G02B 6/2552 reshaping or reforming of light guides for coupling using thermal heating, e.g. tapering, forming of a lens on light guide ends

Abstract

An optical device and methods of using an optical device are provided. The optical device includes a hollow-core fiber including a first portion and a second portion. The first portion includes a hollow core having a first diameter. The second portion includes a hollow core having a second diameter smaller than the first diameter. The difference between the first diameter and the second diameter is less than 10% of the first diameter.

Claims

1. A laser system comprising:

a hollow-core fiber comprising;

a first portion comprising a first hollow core having a first diameter; and

a second portion comprising a second hollow core having a second diameter smaller than the first diameter;

two optical reflectors bounding an optical resonating region, wherein the second portion is within the optical resonating region; and

a gain medium in the optical resonating region, wherein the hollow-core fiber is in optical communication with the gain medium.

2. The laser system of claim 1, wherein the difference between the first diameter and the second diameter is less than 10% of the first diameter.

3. The laser system of claim 1, further comprising at least one lens configured to optically couple light from the hollow-core fiber to the gain medium.

4. The laser system of claim 1, wherein at least one of the optical reflectors is configured to partially transmit light at a wavelength supported by the gain medium.

5. The laser system of claim 1, wherein the hollow-core fiber is configured to filter light at one or more frequencies different from a resonant frequency of the optical resonating region.

6. The laser system of claim 1, wherein the hollow-core fiber is configured to filter light having one or more wavelengths different from a fundamental mode spectrum of the optical resonating region.

7. A method of generating laser light, the method comprising:

providing a hollow-core fiber comprising;

a first portion comprising a first hollow core having a first diameter; and

a second portion comprising a second hollow core having a second diameter smaller than the first diameter, the second optical fiber portion in an optical resonating region;

providing a gain medium in the optical resonating region, the gain medium in optical communication with the hollow-core fiber; and

using the hollow-core fiber to filter light from the gain medium.

8. The method of claim 7, wherein the difference between the first diameter and the second diameter is less than 10% of the first diameter.

9. The method of claim 7, wherein using the hollow-core fiber to filter light from the gain medium comprises removing light having one or more frequencies different from a resonant frequency of the optical resonating region.

10. The method of claim 7, wherein using the hollow-core fiber to filter light from the gain medium comprises removing light having one or more wavelengths different from a fundamental mode spectrum of the optical resonating region.

11. A method of sensing the presence of one or more chemicals or biological materials in a specimen, the method comprising:

providing a hollow-core fiber comprising;

a first portion comprising a first hollow core having a first diameter; and

a second portion comprising a second hollow core having a second diameter smaller than the first diameter, wherein the difference between the first diameter and the second diameter is less than 10% of the first diameter;

inserting the specimen into the hollow-core fiber; and

detecting a transmission spectrum of the hollow-core fiber while the specimen is within the hollow-core fiber, wherein the transmission spectrum is indicative of the presence of a predetermined molecule or molecular species in the specimen.

12. The method of claim 11, wherein the first portion comprises a first cladding having a third diameter and the second portion comprises a second cladding having a fourth diameter, wherein the fourth diameter is smaller than the third diameter.

13. The method of claim 11, wherein detecting a transmission spectrum comprises using a spectrophotometer to measure light transmitted through the hollow-core fiber.

14. The method of claim 11, wherein the transmission spectrum is further indicative of an amount or concentration of the predetermined molecule or molecular species in the specimen.

15. The method of claim 14, wherein an inner surface of the hollow-core fiber is configured to be activated to bind to the predetermined molecule or molecular species.

16. An optical sensor comprising:

a hollow-core fiber comprising;

a first portion comprising a first hollow core having a first diameter; and

a second portion comprising a second hollow core having a second diameter smaller than the first diameter, wherein the difference between the first diameter and the second diameter is less than 10% of the first diameter,

wherein the hollow-core fiber is configured to receive a specimen, the specimen comprising one or more chemicals or biological materials, wherein a transmission spectrum is indicative of the presence of a predetermined molecule or molecular species in the specimen.

17. The optical sensor of claim 16, wherein the first portion comprises a first cladding having a third diameter and the second portion comprises a second cladding having a fourth diameter, wherein the fourth diameter is smaller than the third diameter.

18. The optical sensor of claim 16, further comprising a spectrophotometer configured to measure light transmitted through the hollow-core fiber.

19. The sensor of claim 16, wherein the transmission spectrum is further indicative of an amount or concentration of the predetermined molecule or molecular species in the specimen.

20. The sensor of claim 19, wherein an inner surface of the hollow-core fiber is configured to be activated to bind to the predetermined molecule or molecular species.