Negative curvature fibers

Transcription

1 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

2 Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 2

3 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) 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, (2011). 3

4 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, (2014). F. Yu et al., Opt. Express 20, (2012). A. F. Kosolapov et al., Opt. Express 19, (2011). A. F. Kosolapov et al., Quantum Electronics 46, 267 (2016). R. R. Gattass et al., Opt. Express 24, (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

5 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, (2011). R. R. Gattass et al., Opt. Express 24, (2016). Mid-IR applications Military Medical Sensing C. Wei et al., Front. Phys. 4, 30 (2016). 5

6 Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 6

7 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, (2002) C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 7

8 Slab Waveguide E 2 / E max 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 Effective index Loss (db/m) Antiresonance Band I (a) (b) Mode-matching method Antiresonance Band II Antiresonance Band III FEM x ( µm) C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) Glass thickness (µm) 8

9 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) ~30 db t D core Tube thickness (µm) What is going on besides antiresonance? C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 9

10 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

11 Inhibited coupling in slab waveguides λ = 1 µm Glass Glass Glass Glass W cladding 30 µm W cladding Effective index core mode Effective index Loss (db/m) W cladding (µm) 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

12 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 Δn eff = n eff n eff0 n eff0 is the effective index of waveguide with the middle two glass layers. Loss (db/m) Antiresonance plays a critical role in inhibiting coupling between these modes W cladding (µm) C. Wei et al., Adv. Opt. Photon. 9, 504 (2017) 12

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

14 Inhibited coupling in negative curvature fibers Negative curvature fibers with four cladding tubes show the avoided crossing Effective index d tube (µm) A1 A2 A3 B1 B2 B 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

15 Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 15

16 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) b Leakage loss decreases as the curvature increases. B. Debord et al., Opt. Express 21, (2013). 16

17 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) A. F. Kosolapov et al., Quantum Electronics 46, 267 (2016). Loss (db/m) ~30 db Wavelength ( µm) J. E. Antonip-Lopez, et al.,, in IEEE Photonics Conference (IPC), pp , Nested tubes can increase antiresonance guidance. F. Poletti et al., Opt. Express 22, (2014). 17

18 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 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, (2016). 18

19 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 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) 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, (2016). 250 Power ratio in the tube air (%) Gap (µm) 19

20 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, (2013). M. S. Habib et al., Opt. Express 23, (2015). F. Poletti, Opt. Express 22, (2014). C. Wei et al., Opt. Express 23, (2015). M. Michieletto et al., Opt. Express 24, 7103 (2016). P. Uebel et al., Opt. Lett. 41, 1961 (2016). 20

21 Higher-order mode suppression d D C. Wei et al., Opt. Express 23, (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

22 High loss peaks in bend fibers parallel-polarized t =1.8 µm perpendicular-polarized Bend in x-direction z y x Effective index Loss (db/m) E 2 / E max 2 parallel-polarized perpendicular-polarized Bend radius (cm) 1 0 E 2 / E max 2 C. Wei et al., Opt. Express 24, (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, (2014) E 2 / E E 2 / E max 2 max 2 22

23 Different bend directions Loss (db/m) R = 9.4 cm (during coupling) parallel y perpendicular Bend direction Δθ x Loss (db/m) R = 20.0 cm (away from coupling) parallel perpendicular 0 0 π/8 π/4 Δθ (rad) z y x 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 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, (2016)

24 Bending sensors 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, (2016). R. Gao et al., Opt. Express 25, (2017) 1 0 E 2 / E max 2 24

25 Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 25

26 Mid-IR gas fiber lasers Energy level diagram in acetylene J = 8 J =9 J =7 J =9 Gas cell Energy (a.u.) Measured output spectrum 20 Z. Wang et al., Opt. Express 22, (2014) Wavelength (μm) 26

27 Micromaching Micromaching Glass sheet engraving B. Debord et al., Opt. Express 22, (2014). Micro-milled pattern in a fused silica Cutting of aluminum sheet Marking on a titanium P. Jaworski et al., Opt. Express 21, (2013). 27

28 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, (2013). 28

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

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). High electrical Nonlinear optics conductivity High transparency Chemical sensing in visible and IR Diamagnetism Bend sensing Ultraviolet, mid-ir, and THz transmission 30

31 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, (2013). B. Debord et al., Opt. Express 22, (2014). High electrical Nonlinear optics conductivity High transparency Chemical sensing in visible and IR Diamagnetism Bend sensing Ultraviolet, mid-ir, and THz transmission 31

32 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, (2013). B. Debord et al., Opt. Express 22, (2014). High electrical Nonlinear optics conductivity High transparency Chemical sensing in visible and IR Z. Wang et al., Opt. Express 22, (2014). M. Cassataro et al., Opt. Express 25, 7637 (2017). Y. Chen et al., Opt. Lett. 41, 5118 (2016). Diamagnetism Bend sensing Ultraviolet, mid-ir, and THz transmission 32

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, (2013). B. Debord et al., Opt. Express 22, (2014). High electrical Nonlinear optics conductivity Z. Wang et al., Opt. Express 22, (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, (2005). N. Gayraud et al., Appl. Opt. 47, 1269 (2008). Diamagnetism Bend sensing Ultraviolet, mid-ir, and THz transmission 33

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, (2013). B. Debord et al., Opt. Express 22, (2014). High electrical Nonlinear optics conductivity Z. Wang et al., Opt. Express 22, (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, (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, (2014). R. Gao et al., Opt. Express 25, (2017) 34

35 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, (2013). B. Debord et al., Opt. Express 22, (2014). High electrical Nonlinear optics conductivity Z. Wang et al., Opt. Express 22, (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, (2005). N. Gayraud et al., Appl. Opt. 47, 1269 (2008). Diamagnetism Bend sensing W. Belardi et al., Opt. Express 22, (2014). R. Gao et al., Opt. Express 25, (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

36 Outline Background Guiding mechanism Recent advances Applications Future prospects Summary 36

37 Number of journal publications 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

38 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, (2017). Thank you! 38