Negative curvature fibers - PDF Free Download

Negative curvature fibers presented by Jonathan Hu 1 with Chengli Wei, 1 R. Joseph Weiblen, 2,* and Curtis R. Menyuk 2 1 Baylor University, Waco, Texas 76798, USA 2 University of Maryland Baltimore County, Baltimore, Maryland 21227, USA *Now with the Naval Research laboratory, Washington, DC 20375, USA * 1

Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 2

History of hollow-core optical fiber Step-index fiber: Total internal reflection First photonic crystal fiber: Total internal reflection Solid core photonic crystal fiber: Total internal reflection Hollow core photonic bandgap fiber: Bandgap Bragg fiber: Bandgap Low loss Hollow core photonic bandgap fiber: Bandgap y z x n 0 n 1 n0 TP. V. Kaiser et al., Bell Syst. Tech. J. 53, 1021 (1974). T. A. Birks et al., Opt. Lett. 22, 961 (1997). R. F. Cregan et al., Science 285, 1537 (1999). Y. Fink et al., J. Lightwave Technol. 17, 2039 (1999) C. M. Smith et al., Nature 424, 657 (2003). 1990 2000 2010 1-D antiresonant slab waveguide: Antiresonance 2-D antiresonant waveguide: Antiresonance Hypocycloid-shaped Kagome hollow core fiber Negative curvature hollow core fiber: Antiresonance Chalcogenide negative curvature fiber: Antiresonance M. A. Duguay et al., Appl. Phys. Lett. 49, 13 (1986). N. M. Litchinitser et al., Opt. Express 11, 1243 (2003). Y. Y. Wang et al., CLEO 2010, paper CPDB4. Y. Y. Wang et al., Opt. Lett. 36, 669 (2011). A. D. Pryamikov et al., Opt. Express 19, 1441 (2011). A. F. Kosolapov et al., Opt. Express 19, 25723 (2011). 3

Negative curvature hollow core PCF Positive curvature Flat Negative curvature P. Uebel et al., Opt. Lett. 41, 1961 (2016). X. Liu et al., Opt. Lett. 42, 863(2017). M. Michieletto et al., Opt. Express 24, 7103 (2016) J. R. Hayes et al., J. Lightwave Technol. 35, 437 (2017) A. D. Pryamikov et al., Opt. Express 19, 1441 (2011). A. N. Kolyadin et al., Opt. Express 21, 9514 (2013). A. V. Newkirk et al., Opt. Lett. 41, 3277 (2016) B. Debord et al., Optica 4, 209 (2017) Properties Simple structure Broad bandwidth Low loss transmission High power delivery W. Belardi et al., Opt. Express 22, 10091 (2014). F. Yu et al., Opt. Express 20, 11153 (2012). A. F. Kosolapov et al., Opt. Express 19, 25723 (2011). A. F. Kosolapov et al., Quantum Electronics 46, 267 (2016). R. R. Gattass et al., Opt. Express 24, 25697 (2016). W. Belardi et al., J. Lightw. Technol 33, 4497 (2015). V. Setti et al., Opt. Express 21, 3388 (2013). Y. Y. Wang et al., Opt. Lett. 37, 3111 (2012). Applications Fiber laser Micromachining Surgical procedures... 4

Importance of negative curvature fibers in mid-ir applications Chalcogenide glass: Transmission wavelength extended to mid-ir A. F. Kosolapov et al., Opt. Express 19, 25723 (2011). R. R. Gattass et al., Opt. Express 24, 25697 (2016). Mid-IR applications Military Medical Sensing C. Wei et al., Front. Phys. 4, 30 (2016). 5

Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 6

Antiresonance condition t Glass Resonance condition: 2 2 1/2 glass air t = mλ / [2( n n ) ] k L k T Antiresonance condition: Φ = Φ1 Φ 0 = (2m + 1) π 2 2 1/2 glass air t = ( m+ 0.5) λ / [2( n n ) ] k T : Transverse wave vector k L : Longitudinal wave vector N. M. Litchinitser et al., Opt. Lett. 27, 1592 1594 (2002) C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 7

Slab Waveguide E 2 / E max 2 1.0 0.5 0.0 Glass t z W = 30 µm Glass Air Air Air n 1 = 1.45 n 1 n 0 n 0 = 1.0 n 0 λ = 1 µm y x 0.8 µm Mode-matching method t FEM 0.99987 Effective index 0.99985 10 2 10 1 Loss (db/m) Antiresonance Band I (a) (b) Mode-matching method Antiresonance Band II Antiresonance Band III FEM 0.5 20 10-0 10 20 x ( µm) C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 10 0 02 04 06 08 1 12 14 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Glass thickness (µm) 8

Annular core fiber and negative curvature fiber Annular core fiber 10 3 D core = 30 µm λ = 1 µm D core 10 2 z y x t Negative curvature fiber Loss (db/m) 10 1 10 0 10 1 ~30 db t D core 10 2 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Tube thickness (µm) What is going on besides antiresonance? C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 9

What is going on besides antiresonance? Can we use simple slab waveguides to study the mode coupling between the fundamental core mode and tube mode in negative curvature fibers? Glass Glass Glass Glass W cladding W core W cladding C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 10

Inhibited coupling in slab waveguides 0.9999 λ = 1 µm Glass Glass Glass Glass W cladding 30 µm W cladding Effective index core mode 0.99987 0.9998 10 1 Effective index Loss (db/m) 10 2 10 3 20 40 60 80 100 W cladding (µm) 0.99985 28 29 30 31 W cladding (µm) To inhibit coupling, minimize the overlap between the core and cladding modes (antiresonance) ensure the wavenumbers do not match C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 32 11

Inhibited coupling in slab waveguides 5 t = 0.50 µm t = 0.72 µm (Resonance) (Antiresonance) 10 5 Glass Glass Glass Glass W cladding W core W cladding Δn eff 0 Air Air Air Air Air 5 10 1 Δn eff = n eff n eff0 n eff0 is the effective index of waveguide with the middle two glass layers. Loss (db/m) 10 0 10 1 10 2 Antiresonance plays a critical role in inhibiting coupling between these modes. 10 3 20 40 60 80 100 W cladding (µm) C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 12

Inhibited coupling in negative curvature fibers 0.9998 d tube (µm) 25 20 core mode 15 10 g Effective index d tube l 0.9994 0 2 4 6 g (µm) 8 10 d tube (µm) 10 1 25 20 15 10 Loss (db/m) 10 0 10 1 10 2 0 2 4 6 8 10 g (µm) 10 0 E 2 / E max 2 g = 10 µm g = 5 µm 10 4 g = 0 µm 10 5 0 5 10 l (µm) The mode intensity increases inside the gap when the gap increases from 0 to 10 μm. B. Debord et al., Optica 4, 209 217 (2017). C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 13

Inhibited coupling in negative curvature fibers Negative curvature fibers with four cladding tubes show the avoided crossing 0.9998 Effective index 0.9997 d tube (µm) 40 38 36 34 32 30 28 A1 A2 A3 B1 B2 B3 9 10 11 12 g (µm) Tube mode Core mode A1 A2 A3 1 E 2 / E max 2 D core = 30 µm t = 0.72 µm Core mode Tube mode B1 B2 B3 0 1 E 2 / E max 2 0 C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 14

Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 15

Negative curvature that decrease loss Scanning electronic microscope (SEM) image of the fiber Schematic of the hypocycloid-shaped hollow-core fiber r d bb = dd rr Confinement loss (db/km) 1000 100 10 1 0.00 0.25 0.50 0.75 1.00 b Leakage loss decreases as the curvature increases. B. Debord et al., Opt. Express 21, 28597 (2013). 16

Nested tubes that increase antiresonance guidance Standard y 3-dB contour plots Fabricated fibers with nested tubes t g x Nested R z W. Belardi et al., J. Lightw. Technol 33, 4497 (2015). 10 0 10 1 A. F. Kosolapov et al., Quantum Electronics 46, 267 (2016). Loss (db/m) 10 2 10 3 ~30 db 10 4 1.0 1.2 1.4 1.6 1.8 Wavelength ( µm) J. E. Antonip-Lopez, et al.,, in IEEE Photonics Conference (IPC), pp. 402-403, 2016. Nested tubes can increase antiresonance guidance. F. Poletti et al., Opt. Express 22, 23807 (2014). 17

Fiber with 6, 8, and 10 cladding tubes 10 2 Optimal gap for fibers with 8 and 10 tubes Optimal gap for a fiber with 6 tubes 10 tubes Loss (db/m) 8 tubes 6 tubes 10 3 0 10 20 30 40 Gap (µm) D core =150 µm t =1.8 µm λ =5 µm The optimal gap in a fiber with 6 cladding tubes is 3 times as large as the optimal gap in fibers with 8 or 10 cladding tubes. C. Wei et al., IEEE Photon. J. 8, 2200509 (2016). 18

Comparison between fibers with 6 and 8 cladding tubes y 6 tubes y 8 tubes Gap 1 6 tubes 8 tubes 10 0 Normalized electric field intensity 10 3 0 Intensity at y = 0 x x 10 0 Intensity at y = 0 Gap = 0 µm Gap = 0 µm. Gap = 10 µm Normalized electric field intensity 10 3 x ( µm) 250 0 x ( µm). Gap = 10 µm A larger gap is required to remove the weak coupling between the core mode and tube modes in a fiber with 6 cladding tubes. C. Wei et al., IEEE Photon. J. 8, 2200509 (2016). 250 Power ratio in the tube air (%) 0 0 10 20 30 40 Gap (µm) 19

Higher-order mode suppression Effective index High loss J. M. Fini et. al., Opt. Express 21, 6233 (2013) J. M. Fini et. al., Nat. Commun. 5, 5085 (2014) Tube diameter Use coupling to suppress higher-order core modes! B. Debord et al., Opt. Express 21, 28597 (2013). M. S. Habib et al., Opt. Express 23, 17394 (2015). F. Poletti, Opt. Express 22, 23807 (2014). C. Wei et al., Opt. Express 23, 15824 (2015). M. Michieletto et al., Opt. Express 24, 7103 (2016). P. Uebel et al., Opt. Lett. 41, 1961 (2016). 20

Higher-order mode suppression d D C. Wei et al., Opt. Express 23, 15824 (2015). P. Uebel et al., Opt. Lett. 41, 1961 (2016). M. Michieletto et al., Opt. Express 24, 7103 (2016). C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 21

High loss peaks in bend fibers 1.0005 5 parallel-polarized t =1.8 µm perpendicular-polarized Bend in x-direction z y x Effective index Loss (db/m) 1.0000 0.9995 10 3 10 2 1 0 5 E 2 / E max 2 parallel-polarized perpendicular-polarized 5 10 15 20 25 Bend radius (cm) 1 0 E 2 / E max 2 C. Wei et al., Opt. Express 24, 12228 (2016). R = 5.7 cm R = 9.4 cm Parallel Perpendicular y x Bend-loss peaks are induced by mode coupling Fibers with small tubes have lower bend loss W. Belardi et al., Opt. Express 22, 10091 (2014). 1 0 1 0 E 2 / E E 2 / E max 2 max 2 22

Different bend directions Loss (db/m) 100 80 60 40 20 R = 9.4 cm (during coupling) parallel y perpendicular Bend direction Δθ x Loss (db/m) 0.05 0.04 0.03 0.02 R = 20.0 cm (away from coupling) parallel perpendicular 0 0 π/8 π/4 Δθ (rad) z y x 0.01 0 π/8 π/4 Δθ (rad) Δθ = 0 1 Δθ = π/8 1 Δθ = 0 1 Δθ = π/8 1 E 2 / E max 2 E 2 / E max 2 E 2 / E max 2 E 2 / E max 2 0 0 The bend loss changes by a maximum factor of 10 as the bend direction changes when coupling happens. C. Wei et al., Opt. Express 24, 12228 (2016). 0 0 23

Bending sensors http://coolshitindustries.com/2011/10/data glove-with-ghetto-flex-sensors-circa-2000/ Straight 1 0 E 2 / E max 2 Bend radius = R 1 0 E 2 / E max 2 Bend radius = 2R This negative curvature fiber could be used to make bending sensors. C. Wei et al., Opt. Express 24, 12228 (2016). R. Gao et al., Opt. Express 25, 18081 (2017) 1 0 E 2 / E max 2 24

Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 25

Mid-IR gas fiber lasers Energy level diagram in acetylene J = 8 J =9 J =7 J =9 Gas cell Energy (a.u.) 120 100 80 60 40 Measured output spectrum 20 http://www.glophotonics.fr/index.php/product-2.html Z. Wang et al., Opt. Express 22, 21872 (2014). 0 3.05 3.10 3.15 3.20 3.25 Wavelength (μm) 26

Micromaching Micromaching Glass sheet engraving http://www.warsash.com.au/products/laser-systems/micromachining.php B. Debord et al., Opt. Express 22, 10735 (2014). Micro-milled pattern in a fused silica Cutting of aluminum sheet Marking on a titanium P. Jaworski et al., Opt. Express 21, 22742 (2013). 27

Surgical procedures A fiber mounted with the end tip using a heat shrinking tube Ablation of ovine bone in air Sapphire tube Negative curvature fiber 0.5 mm Sapphire window 1.2 mm 1.4 mm A. Urich et al., Biomed. Opt. Express 4, 193 205 (2013). 28

Outline Background Antiresonant reflection and inhibited coupling Recent advances Applications Future prospects Summary 29

Future prospects High Data electron communications mobility High mechanical Power delivery stiffness and flexibility J. R. Hayes et al., J. Lightwave Technol. 35, 437 (2017). F. Poletti et al., Nat. Photonics 7, 279 (2013). High electrical Nonlinear optics conductivity High transparency Chemical sensing in visible and IR Diamagnetism Bend sensing Ultraviolet, mid-ir, and THz transmission 30

Future prospects High Data electron communications mobility High mechanical Power delivery stiffness and flexibility J. R. Hayes et al., J. Lightwave Technol. 35, 437 (2017). F. Poletti et al., Nat. Photonics 7, 279 (2013). Y. Y. Wang et al., Opt. Lett. 37, 3111 (2012). P. Jaworski et al., Opt. Express 21, 22742 (2013). B. Debord et al., Opt. Express 22, 10735 (2014). High electrical Nonlinear optics conductivity Z. Wang et al., Opt. Express 22, 21872 (2014). M. Cassataro et al., Opt. Express 25, 7637 (2017). Y. Chen et al., Opt. Lett. 41, 5118 (2016). High transparency Chemical sensing in visible and IR X. Liu et al., Opt. Lett. 42, 863 (2017). S. Ghosh et al., Phys. Rev. Lett. 94, 093902 (2005). N. Gayraud et al., Appl. Opt. 47, 1269 (2008). Diamagnetism Bend sensing Ultraviolet, mid-ir, and THz transmission 33

Future prospects High Data electron communications mobility High mechanical Power delivery stiffness and flexibility J. R. Hayes et al., J. Lightwave Technol. 35, 437 (2017). F. Poletti et al., Nat. Photonics 7, 279 (2013). Y. Y. Wang et al., Opt. Lett. 37, 3111 (2012). P. Jaworski et al., Opt. Express 21, 22742 (2013). B. Debord et al., Opt. Express 22, 10735 (2014). High electrical Nonlinear optics conductivity Z. Wang et al., Opt. Express 22, 21872 (2014). M. Cassataro et al., Opt. Express 25, 7637 (2017). Y. Chen et al., Opt. Lett. 41, 5118 (2016). High transparency Chemical sensing in visible and IR X. Liu et al., Opt. Lett. 42, 863 (2017). S. Ghosh et al., Phys. Rev. Lett. 94, 093902 (2005). N. Gayraud et al., Appl. Opt. 47, 1269 (2008). Diamagnetism Bend sensing Ultraviolet, mid-ir, and THz transmission W. Belardi et al., Opt. Express 22, 10091 (2014). R. Gao et al., Opt. Express 25, 18081 (2017) 34

Future prospects High Data electron communications mobility High mechanical Power delivery stiffness and flexibility J. R. Hayes et al., J. Lightwave Technol. 35, 437 (2017). F. Poletti et al., Nat. Photonics 7, 279 (2013). Y. Y. Wang et al., Opt. Lett. 37, 3111 (2012). P. Jaworski et al., Opt. Express 21, 22742 (2013). B. Debord et al., Opt. Express 22, 10735 (2014). High electrical Nonlinear optics conductivity Z. Wang et al., Opt. Express 22, 21872 (2014). M. Cassataro et al., Opt. Express 25, 7637 (2017). Y. Chen et al., Opt. Lett. 41, 5118 (2016). High transparency Chemical sensing in visible and IR X. Liu et al., Opt. Lett. 42, 863 (2017). S. Ghosh et al., Phys. Rev. Lett. 94, 093902 (2005). N. Gayraud et al., Appl. Opt. 47, 1269 (2008). Diamagnetism Bend sensing W. Belardi et al., Opt. Express 22, 10091 (2014). R. Gao et al., Opt. Express 25, 18081 (2017) Ultraviolet, mid-ir, and THz transmission A. N. Kolyadin et al., Opt. Express 21, 9514 (2013). A. D. Pryamikov et al., Quantum Electron. 46, 1129 (2016). V. Setti et al., Opt. Express 21, 3388 (2013). 35

Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 36

Number of journal publications 38 22 14 15 18 1 0 2 4 5 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 Year (As of June) Number of journal publications related to hollow-core fibers that use a negative curvature inner core boundary. C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 37

Summary Inhibited coupling guides the light negative curvature fibers. Recent advances have increased their performance of the negative curvature fibers. Negative curvature fibers enable a large range of applications. Negative curvature fibers will be the best choice for a wide range of different applications due to their combined advantages of low loss, broad bandwidth, and a low power ratio in the glass. The content of this talk has been adapted from the review paper, C. Wei et. al., Adv. Opt. Photon. 9, 504 561 (2017). Thank you! 38