Light propagation in Photonic. Crystal. Fibers infiltrated with Nematic. Liquid

Transcription

1 Light propagation in Photonic Crstal Fibers infiltrated with Nematic Liquid Crstals Tomasz R. Wolinski,, K. A. Brzdakiewicz, P. Lesiak, S. rtman,, A. Czapla, K. Nowecka, and A. W. Domanski Facult of Phsics, Warsaw Universit of Technolog, Warszawa, Poland

2 Collaboration (since 95) 95): Facult of Phsics, WUT HDr. A. Domański, assoc. prof. HDr. M. Karpierz, prof. Dr. T. Nasiłowski (VUB) Dr. A. Szmańska (WUT) Dr. P. Lesiak Dr. M. Sierakowski Dr. K. Brzdąkiewicz K. Szaniawska, PhD student S. rtman, PhD student A. Czapla, MSc K. Nowecka, MSc & Co-workers Institute of Chemistr MTU Prof. Roman Dąbrowski & Co-workers Institute of Phsics MTU Dr.. Nowinowski-Kruszelnicki & Co-workers UMCS Lublin Dr. Jan Wójcik & Co-workers Facult of Mechatronis WUT: Prof. M. Kujawińska & Co-workers

3 Outline Motivation: PCF and LC Polarization phenomena in HB PMFs Highl birefringent PLCFs Theoretical analses perimental verification Research trends

4 Photonic Crstal Fibers a cladding made of a Photonic Crstal a core created b a defect in the PC structure

5 Solid-core Photonic Crstal Fibers highl nonlinear endlessl single-mode polarization maintaining with high numerical aperture

6 Background: HB fibers T. R. Woliński, Progress in Optics ed.. Wolf, vol XL, pp (000)

7 Lowest-order HB fibers

8 Photonic Liquid Crstal Fiber (PLCF) Photonic Crstal Fibers Advantages of both mtir and PBG phenomena Variet of PCF structures (birefringence, SM, nonlinearit, etc.) Liquid Crstals Thermal, eternal ac & dc fields, optical field sensitivit Variet of LC materials and LC structures; influence of molecular ordering Tha highest level of tunabilit of propagation and polariation properties b eternal fields

9 Highl birefringent PCF + LC Pitch, Λ: 4.4 µm Large hole diameter: 4.5 µm Small hole diameter:. µm Diameterwith of thelc hole region: 40 µm PMD: PM Large holes filled b capillar forces.75 ps/m

10 Theoretical analses Starting from Mawell s equations we obtain the vector wave equation r r (for a linear, isotropic, and time-invariant medium) = = ep( ) ikn r ( ) = n k z) r eff where field envelope (, ) ) r where: k=π/λ for n=n(, ) we re looking for solutions in the form: considering onl and components ) = ) ( ), ) (, ) = is z-invariant ) we obtain

11 Vectorial mode solver = eff N k P P P P ( ) k n n n 1 P + + = ( ) k n n n 1 P + + = n n 1 P = n n 1 P = where: Cross-coupling effects between transverse fields

12 Theoretical calculations M = k eigenvalue problem for both and field problem discretization using finite-difference technique implementation of Matlab librar for finding eigenvalues and eigenmodes matri M contains absorbing boundar conditions, N eff, grid period: 0.1μm -10 (in both and direction) -0 calculating window: 48.4μm 48.4mm (all hole region) refractive inde of the glass cladding: λ=1550nm

13 Fundamental mode LP01 as a function of LC refractive inde

14 Change of the birefringence aes HB PCF Fast ais Slow ais PLCF ( large holes infilled) Slow ais Fast ais

15 6 *10-4 Modal birefringence B n LC (fundamental mode LP 01 )

16 n LC =1.4 n LC =1.46 LP 11 e LP 11 e LP 0 LP 03 LP 11 e LP 11 o LP 1 e Higher order modes n LC =1.5 LP 1 o LP 0 LP 04

17 Propagation properties of LP modes Neff LP 01 LP 0 LP 03 LP LP 11 e LP 1 e LP 13 e LP n LC

18 Modal birefringence * LP 11 e LP 04 0 LP 0 LP 03 B -1 LP 01 LP 13 e - -3 LP 1 e n LC

19 Temperature dependence of LC refractive indices (λ = 589 nm) 1.78 refractive indices n e n o 1550 PCB silica 1.48 n e 1.43 n o temperature [Celsius deg.]

20 perimental setup thermo-electric electric module PAT 9000B

21 ndface of the PCF and PLCF unfilled (PCF) filled (PLCF) Laser off Laser on

22 Polarization modulation in HB Fibers a) b) PANDA fiber Blazephotonics + LC 1550 (thermal tuning)

23 Intermodal Δλ for PLCF filled with 1550 NLC Δλ [a. u.]

24 1110 PCB B Modal Δλ as a function of temp. for PLCF filled with NLC:

25 Calculated PMD as a function of temperature for PLCF filled with: fundamental mode fundamental mode 194 1B 1110 higher order mode higher order mode PCB

26 Research trends Tuning mechanisms: thermal, electrical, optical In-line polarization and spatial modes switching Nonlinear effects: all-optical switching Tunable birefringence and wavelength filtering Photoalignment Multi-parameter fiber optic sensing Dnamic PMD compensators

27 Photonic Liquid Crstal Fibers a new level of tunabilit it in photonics

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