Temperature tuning of dispersion in photonic band gap fiber

• US 6,826,342 B1
• Filed: 03/13/2003
• Issued: 11/30/2004
• Est. Priority Date: 03/13/2003
• Status: Active Grant

• Current Assignee: Furukawa Electric North America Incorporated (Furukawa Electric Company Limited)
• Original Assignee: Fitel USA Corporation
• Inventors: Bise, Ryan, Jasapara, Jayesh
• Primary Examiner(s): Sanghavi, Hemang
• Application Number:
  US10/388,110
• Time in Patent Office: 628 Days
• Field of Search: 385/123-127, 385/129, 385/27, 398/82-88
• US Class Current: 385/125
• CPC Class Codes: G02B 6/0238 Longitudinal structures having higher refractive index than background material, e.g. high index solid rods
• CPC Class Codes: G02B 6/02385 Comprising liquid, e.g. fluid filled holes
• CPC Class Codes: G02B 6/0239 Comprising means for varying the guiding properties, e.g. tuning means
• CPC Class Codes: G02F 1/0147 based on thermo-optic effects G02F1/132 takes precedence
• CPC Class Codes: G02F 2202/32 Photonic crystals

Abstract

A photonic band gap fiber structure is formed to include a plurality of filled air holes surrounding a solid silica core region. The material used to fill the air holes is chosen to exhibit an index of refraction that is greater than the index of the core, where the fill material refractive index is also adjustable as a function of temperature. Therefore, by adjusting the temperature of the PBG fiber, the dispersion characteristic of the propagating signal can be modified.

Claims

1. A photonic band gap fiber structure comprising

a core region of a material exhibiting a relatively low index of refraction;

a lattice-structured region surrounding said core region, the lattice-structured region comprising a plurality of air holes with at least a longitudinal extent of said plurality of air holes filled with a material exhibiting a temperature-dependent index of refraction wherein the room temperature value of the temperature-dependent index of refraction is greater than the relatively low index of refraction associated with said core region, wherein the dispersion value associated with said photonic band gap fiber structure is controlled by controlling the temperature of said photonic band gap fiber structure.

2. A photonic band gap fiber structure as defined in claim 1 wherein the core region comprises silica.

3. A photonic band gap fiber structure as defined in claim 1 wherein the plurality of air holes are filled with a liquid material exhibiting a temperature-dependent index of refraction less than the index of refraction of the core region.

4. A photonic band gap fiber structure as defined in claim 3 wherein the liquid exhibits a temperature-dependent index of refraction change of approximately −

6.8*10<sup>−

4</sup>/°

C.

5. A photonic band gap fiber structure as defined in claim 1 wherein the core region comprises silica with an index of refraction of approximately 1.4 and the material filled in the plurality of air holes exhibits a room temperature index of refraction of approximately 1.8.