Optical Glass and Fibre Fabrication

Transcription

1 Optical Glass and Fibre Fabrication Heike Ebendorff-Heidepriem Institute for Photonics & Advanced Sensing The University of Adelaide, Australia member of Optofab Node capabilities and procedures for glass, preform and fibre fabrication

2 Capabilities Glass Preform Fibre Bulk Macroscopic Structure Nano/Micro Structure open air & controlled atm melting facilities (up to 1300 o C) extrusion (soft glass & silica) MCVD lathe (silica) ultrasonic drilling drawing towers (soft glass & silica)

3 Glass Melting melt-quench technique: based on fusion/melting of powdered crystalline raw materials flexibility in volume, shape, composition batching = mixture of powdered crystalline raw materials heating of raw materials within crucible fusion of raw materials = liquid formation casting into mould to form into a shape annealing and slow cooling to room temp. Melting Furnace Annealing Furnace Crucible Preheated Mould

4 Glass Melting Controlled Atmosphere Glass Melting for Oxide Glass (max 1300 o C) open air dry air Ho 3+ doped germanate glass nanodiamond doped tellurite glass Glasses with mid-ir transmission, high index, high nonlinearity, high doping concentration: tellurite glass: low melting temperature, visible-ir nanocrystal doping: diamond, gold, silicon, upconverter) germanate glass: higher stability compared with tellurite promising for high power fibre lasers at 2-2.5µm supercontinuum generation

5 Glass Melting Controlled Atmosphere Glass Melting for Fluoride Glass (max 900 o C) Tellurite ZBLAN InF 3 ZBLAN glass: transmission up to 5µm InF 3 -based glass: transmission up to 6µm upconversion and mid-ir lasers (0.4-4µm) Fluoride-Phosphate glass: OSL dosimetry rare earth doping up to 4mol%

6 Glass Melting develop and fabricate wide range of glass compositions low-water glasses, adjust redox state using controlled atmosphere (N 2, O 2, SF 6 ) fabrication of bulk glass up to 300g capabilities for glass polishing and characterization current research: - mid-infrared glasses for laser and optical nonlinearity (fluoride, tellurite, germanate) - embedding nanocrystals in glass (e.g. nanodiamond in tellurite) H. Ebendorff-Heidepriem, et al., Opt. Lett. 33, 2861 (2008) M. Oermann, et al., Opt. Express, 17, (2009) D. Lancaster, et al., Opt. Lett. 36, 1587 (2011) M. Henderson, et al., Adv. Mater. 23, 2806 (2011)

7 Glass Extrusion versatile technique to fabricate air/glass structures glass billet 1.) heating of billet to softening point 2.) forcing soft material through die die geometry preform geometry steel die Versatile: - many glass compositions - many structures Single step: form holes simultaneously Automated: highly reproducible glass preform ~150mm used for drawing OD=16mm

8 Glass Extrusion Soft Glass Extrusion ( o C) extruded materials: polymer lead-silicate glasses bismuth glasses tellurite glasses fluoride glasses chalcogenide glasses fluoride-phosphate glasses lead-germanate glasses extruded structures: large number of features non-circular holes non-symmetric shapes highly porous structures H. Ebendorff-Heidepriem, T.M. Monro, Opt. Express 15, (2007) H. Ebendorff-Heidepriem, et al., Opt. Lett. 33, 2861 (2008) S. Warren-Smith, et al., Opt. Express 17, (2009) S. Atakamarians, et al., Opt. Express 17, (2009)

9 Glass Extrusion Hard Glass Extrusion ( o C) extruded materials: borosilicate BK7 (~700 o C) Ba-germanate (~800 o C) Al-La-silicate (~1000 o C) future: silica ( o C) extruded structures: rod tube suspended core

10 Silica Preform Fabrication via Modified Chemical Vapor Deposition 1. metal halides with low boiling point soot deposit 2. sintering of soot into glass used for doped silica preform fabrication extremely high purity low loss clad core SiCl 4 + O 2 SiO 2 + 2Cl 2 GeCl 4 + O 2 GeO 2 + 2Cl 2 4POCl 3 + 3O 2 2P 2 O 5 + 6Cl 2 4BBr 3 + 3O 2 2B 2 O 3 + 6Br 2 John B. Mac Chesney, Materials and Processes for Preform Fabrication- Modified Chemical Vapor Deposition and Plasma Chemical Vapor Deposition. Proc. IEEE, 68, 10, 1181 (1980)

11 Silica Preform Fabrication via Modified Chemical Vapor Deposition facility is the first to produce on-line hydrogen, oxygen and nitrogen generation Ge, P, B, Al, rare earth doping different doping concentrations range of index profiles (step-index, W, pedestal)

12 Silica Preform Fabrication via Ultrasonic Drilling hexagonal outer shape for solid double clad fibres air holes for air-jacket double clad fibres air holes for microstructured fibres with suspended and exposed cores Drilling Cutting Milling

13 Fibre Drawing Soft Glass Draw Tower (4m, max 900 o C) micro/nanostructured fibres nanoscale fibre features (core, hole) hollow-core, triple core different hole sizes large number of features mixing different glasses

14 Fibre Drawing Silica Draw Tower (6m, max 2200 o C) step-index and microstructured silica fibres rare-earth doped double clad JAC fibre laser suspended and exposed core fibres with varying core and hole size sensing

15 Optical Glass and Fibre Fabrication Thank You!