Lightwave Technol Research Articles

Photochemical bonding of special optical fibers

The most popular method for permanent connecting of an optical fibers is a thermal bonding with a fusion or filament splicers. However this method in some cases is not suitable, for example if connected fibers are made of materials with different melting temperatures (i.e. silica and “soft glass fibers) or in the case of microstructured optical fibers filled with materials, which are highly sensitive for high temperature (i.e. organic materials such a liquid crystals). In this work we will present some practical issues of an alternative method of permanent connecting of various types of optical fibers by gluing with use of photo-curable adhesives. Full Text: PDF References J. Ballato and A. F. Abouraddy, Feature issue introduction: specialty optical Opt. Mater. Express 2, 1680-1682 (2012) CrossRef I. Hatakeyama and H. Tsuchiya, splices for single-mode optical IEEE Journal of Quantum Electronics 14, 614-619 (1978) CrossRef K. Inada, O. Watanabe and H. Taya, Splicing of Fibers by the Fusion Method, IEEE Journal on Selected Areas in Communications 4, 706 – 713 (1986) CrossRef L. Xiao, M.S. Demokan, W. Jin, Y. Wang and C. Zhao, Fusion Splicing Photonic Crystal Fibers and Conventional Single-Mode Fibers: Microhole Collapse Effect, J. Lightwave Technol. 25, 3563 – 3574 (2007) CrossRef R.Al-Mahrous, R.Caspary and W.Kowalsky, A thermal splicing method to join silica and fluoride fibers, J. Lightwave Technol. 32 302–308 (2014) CrossRef S. Ertman, A. H. Rodriguez, M. M. Tefelska, M. S. Chychlowski, D. Pysz, R. Buczynski, E. Nowinowski-Kruszelnicki, R. Dąbrowski, and T. R. Wolinski, Index guiding photonic liquid crystal fibers for practical applications, J. Lightwave Technol. 30, 1208 - 1214 (2012) CrossRef M. M. Kozak, W. Kowalsky and R. Caspary, Low-loss glue splicing method to join silica and fluoride fibers, Electron. Lett. 41, 21–22, (2005) CrossRef R. Al-Mahrous, R. Caspary, and W. Kowalsky, A Glue Splicing Method to Join Silica and Fluoride Fibers With Low Attenuation, J. Lightwave Technol. 32, 1669-1673 (2014) CrossRef

Graphene-based, ultrafast Er-doped fiber laser with linearly polarized output pulses

We demonstrate an all-fiber, Er-doped fiber laser mode-locked with a graphene-based saturable absorber. The resonator is designed using only polarization maintaining fibers and components, which allows to achieve linearly polarized output beam. The laser delivers 595 fs long pulses at 1560 nm center wavelength with 6.3 nm bandwidth and 67 MHz repetition rate. As a saturable absorber, a graphene-polymer composite was used. Full Text: PDF References Q. L. Bao, H. Zhang, Y. Wang, Z. H. Ni, Z. X. Shen, K. P. Loh, D. Y. Tang, "Atomic-Layer Graphene as a Saturable Absorber for Ultrafast Pulsed Lasers", Adv. Funct. Mater. 19, 3077 (2009). CrossRef T. Hasan, Z. Sun, F. Wang, F. Bonaccorso, P. H. Tan, A. G. Rozhin, A.C. Ferrari, "Nanotube?Polymer Composites for Ultrafast Photonics", Adv. Mater. 21, 3874 (2009). CrossRef H. Zhang, D. Y. Tang, L. M. Zhao, Q. L. Bao, and K. P. Loh, "Large energy mode locking of an erbium-doped fiber laser with atomic layer graphene", Opt. Express 17, 17630 (2009). CrossRef Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, A. C. Ferrari, "Graphene Mode-Locked Ultrafast Laser", ACS Nano 4, 803 (2010). CrossRef Z. Sun, D. Popa, T. Hasan, F. Torrisi, F. Wang, E. JR Kelleher, J. C Travers, V. Nicolosi, A. C Ferrari, "A stable, wideband tunable, near transform-limited, graphene-mode-locked, ultrafast laser", Nano Res. 3, 653 (2010). CrossRef D. Popa, Z. Sun, F. Torrisi, T. Hasan, F. Wang, and A. C. Ferrari, "Sub 200 fs pulse generation from a graphene mode-locked fiber laser", Appl. Phys. Lett. 97, 203106 (2010). CrossRef H. Zhang, D. Y. Tang, L. M. Zhao, Q. L. Bao, K. P. Loh, B. Lin, and S. C. Tjin, "Compact graphene mode-locked wavelength-tunable erbium-doped fiber lasers: from all anomalous dispersion to all normal dispersion", Laser Phys. Lett. 7, 591 (2010). CrossRef H. Zhang, Q. Bao, D. Tang, L. Zhao, and K. Loh, "Large energy soliton erbium-doped fiber laser with a graphene-polymer composite mode locker", Appl. Phys. Lett. 95, 141103 (2009). CrossRef J. Xu, S. Wu, H. Li, J. Liu, R. Sun, F. Tan, Q.-H. Yang, P. Wang, "Dissipative soliton generation from a graphene oxide mode-locked Er-doped fiber laser", Opt. Express 20, 23653 (2012). CrossRef P.L. Huang, S. Lin, C. Yeh, H. Kuo, S. Huang, G. Lin, L. Li, C. Su, W. Cheng, "Stable mode-locked fiber laser based on CVD fabricated graphene saturable absorber", Opt. Express 20, 2460 (2012) CrossRef X.H. Li, Y.G. Wang, Y.S. Wang, Y.Z. Zhang, K. Wu, P.P. Shum, X. Yu, Y. Zhang, Q.J. Wang, "All-normal-dispersion passively mode-locked Yb-doped fiber ring laser based on a graphene oxide saturable absorber", Laser Phys Lett. 10, 075108 (2013). CrossRef M. Zhang, E. J. R. Kelleher, F. Torrisi, Z. Sun, T. Hasan, D. Popa, F. Wang, A. C. Ferrari, S. V. Popov, and J. R. Taylor, "Tm-doped fiber laser mode-locked by graphene-polymer composite" Opt. Express 20, 25077 (2012). CrossRef Q. Wang, T. Chen, B. Zhang, M. Li, Y. Lu, and K. P. Chen, "All-fiber passively mode-locked thulium-doped fiber ring laser using optically deposited graphene saturable absorbers", Appl. Phys. Lett. 102, 131117 (2013). CrossRef G. Sobon, J. Sotor, I. Pasternak, A. Krajewska, W. Strupinski, K. M. Abramski, "Thulium-doped all-fiber laser mode-locked by CVD-graphene/PMMA saturable absorber", Opt. Express 21, 12797 (2013). CrossRef G. Sobon, J. Sotor, I. Pasternak, K. Grodecki, P. Paletko, W. Strupinski, Z. Jankiewicz, K.M. Abramski, "Er-Doped Fiber Laser Mode-Locked by CVD-Graphene Saturable Absorber", J. Lightwave Technol. 30, 2770 (2012). CrossRef A. Martinez, K. Fuse, B. Xu, and S. Yamashita, "Optical deposition of graphene and carbon nanotubes in a fiber ferrule for passive mode-locked lasing", Opt. Express 18, 23054 (2010). CrossRef Y. M. Chang, H. Kim, J. H. Lee, and Y. Song, "Multilayered graphene efficiently formed by mechanical exfoliation for nonlinear saturable absorbers in fiber mode-locked lasers", Appl. Phys. Lett. 97, 211102 (2010). CrossRef A. Martinez, K. Fuse, and S. Yamashita, "Mechanical exfoliation of graphene for the passive mode-locking of fiber lasers", Appl. Phys. Lett. 99, 121107 (2011). CrossRef G. Sobon, J. Sotor, K. M. Abramski, "All-polarization maintaining femtosecond Er-doped fiber laser mode-locked by graphene saturable absorber", Laser Phys. Lett. 9, 581 (2012). CrossRef J. Sotor, G. Sobon, K. M. Abramski, "Scalar soliton generation in all-polarization-maintaining, graphene mode-locked fiber laser", Opt. Lett. 37, 2166 (2012). CrossRef M. L. Dennis, I. N. Duling III, "Experimental study of sideband generation in femtosecond fiber lasers", IEEE J. Quantum Electron. 30, 1469 (1994) CrossRef

Design of a GaP/Si composite waveguide for CW terahertz wave generation via difference frequency mixing.

We design a GaP/Si composite waveguide to achieve efficient terahertz (THz) wave generation under collinear phase-matched difference frequency mixing (DFM) between near-infrared light sources. This waveguide structure provides a strong mode confinement of both near-infrared sources and THz wave, resulting in an efficient mode overlapping. The numerical results show that the waveguide can produce guided THz wave (5.93 THz) with a power conversion efficiency of 6.6×10(-4) W(-1). This value is larger than previously obtained with the bulk GaP crystal: 0.5×10(-9) W(-1) [J. Lightwave Technol.27, 3057 (2009)]. Our proposed composite waveguide can be achieved by bridging the telecom wavelength and THz frequency region.

Nonlinear spectral management: Linearization of the lossless fiber channel

Using the integrable nonlinear Schrödinger equation (NLSE) as a channel model, we describe the application of nonlinear spectral management for effective mitigation of all nonlinear distortions induced by the fiber Kerr effect. Our approach is a modification and substantial development of the so-called "eigenvalue communication" idea first presented in A. Hasegawa, T. Nyu, J. Lightwave Technol. 11, 395 (1993). The key feature of the nonlinear Fourier transform (inverse scattering transform) method is that for the NLSE, any input signal can be decomposed into the so-called scattering data (nonlinear spectrum), which evolve in a trivial manner, similar to the evolution of Fourier components in linear equations. We consider here a practically important weakly nonlinear transmission regime and propose a general method of the effective encoding/modulation of the nonlinear spectrum: The machinery of our approach is based on the recursive Fourier-type integration of the input profile and, thus, can be considered for electronic or all-optical implementations. We also present a novel concept of nonlinear spectral pre-compensation, or in other terms, an effective nonlinear spectral pre-equalization. The proposed general technique is then illustrated through particular analytical results available for the transmission of a segment of the orthogonal frequency division multiplexing (OFDM) formatted pattern, and through WDM input based on Gaussian pulses. Finally, the robustness of the method against the amplifier spontaneous emission is demonstrated, and the general numerical complexity of the nonlinear spectrum usage is discussed.

Periodic arrays of gold nano-disks coupled with evanescent spectroscopy

We study and analyze various spectral features of gold nano-disk arrays coupled with the evanescent field of an optical waveguide using finite difference time domain simulations for comparison to our previous work on this topic [Jiang et al., J. Lightwave Technol. 27(13), 2264–2270 (2009)]. We find that the quadrupolar and dipolar peaks are both heavily dependent on the coherent interactions of the periodic array and show comparable performance for refractive index sensing applications. We also find sharp extinction peaks and dips in the simulated spectra, but they are not sensitive to the index change of the surface-bound layer. A detailed analysis on these sharp features reveals that the sharp extinction peaks are grating-induced quadrupolar modes and the dips represent the suppressed plasmon resonances caused by the photonic band gap.

Influence of Electric Field on the Orientation of Ferroelectric Liquid Crystals inside micro capillaries

In the paper we present recent results on investigation of ferroelectric liquid crystals molecules orientation inside photonic crystal fibers, which consist of a set of micro capillaries. We have infiltrated glass micro capillaries with different inner diameters with the experimental ferroelectric liquid crystal mixture W-206K. The orientation of the liquid crystal molecules was controlled by the external electric field applied to the sample. We have obtained promising results about the orientation of the ferroelectric liquid crystal molecules and their behavior under influence of applied external electric field. The presented results may lead to design a new class of fast-switching fiber optic sensors. Full Text: PDF References P. St.J. Russell, "Photonic-Crystal Fibers", J. Lightwave Technol. 24, 4729-4749 (2006). CrossRef T. Larsen, A. Bjarklev, D. Hermann, and J. Broeng, "Optical devices based on liquid crystal photonic bandgap fibres", Opt. Express 11, 2589-2596 (2003). CrossRef T. R. Wolinski, K. Szaniawska, K. Bondarczuk, P. Lesiak, A.W. Domanski, R. Dabrowski, E. Nowinowski-Kruszelnicki, J. Wojcik, "Propagation properties of photonic crystal fibers filled with nematic liquid crystals", Opto-Electronics Rev. 13(2), 177-182 (2005). DirectLink M.W. Haakestad, et al., "Electrically tunable photonic bandgap guidance in a liquid-crystal-filled photonic crystal fiber", IEEE Photon. Technol. Lett. 17, 819–821 (2005). CrossRef Matuszczyk M. "Structures and Properties of Ferroelectric Liquid Crystal Displays", Goteborg, Sweden, Chalmers Reproservice (1996). Q. Guo, E. P. Pozhidaev, A. K. Srivastava, Y. Ma, X. Wang, V. G. Chigrinov, H. S. Kwok, "Deformed Helix Ferroelectric Display with Low Driving Voltage and Fast Response Time", SID Symposium Digest of Technical Papers, Vol. 43 (1), 449-451, (2012). CrossRef E. P. Pozhidaev et al., "High Frequency Low Voltage Shock-Free Ferroelectric Liquid Crystal: A New Electro-Optical Mode with Electrically Suppressed Helix", Proc. of 31-th International Display Research Conference EuroDisplay 2011, Bordeaux-Arcachon, France, September 19-22 (2011). DirectLink Vladimir Chigrinov, Eugene Pozhidaev, Abhishek Srivastava, Guo Qi, Ma Ying, Hoi Sing Kwok, "Fast Ferroelectric Liquid Crystal Modes Based on Photoaligning Technology", SID 2013, Vancouver, Canada, May 2013 Clark, N. A. and S. T. Lagerwall, "Submicrosecond bistable electro-optic switching in liquid crystals", Appl. Phys. Lett. Vol. 36, 899-901(1980). CrossRef S. Mathews, Y. Semenova, G. Rajan, G. Farrell, "Tunable properties of Liquid Crystal filled Photonic Crystal Fibers", Proc. SPIE 7316, 73161E (2009). CrossRef D. Budaszewski, T.R. Woliński, M. A. Geday, J. M. Otón, "Photonic Crystal Fibers infiltrated with Ferroelectric Liquid Crystals", Phot. Lett. Poland 2(3) (2010). CrossRef

Modeling of Wide-Band Optical Signal Amplification in an EDFA Network Using Tunable Tap

Optical amplification in C and L band region with wave division multiplexing can provide over 160 channels. The paper provides simulation studies of such a wideband erbium doped fiber amplifier which utilizes a tunable tap at the TLS source end. This isolates and provides two parallel channels for simultaneous amplification in both C and L band. Such a configuration has shown to provide a gain well over 20dB from 1525-1615nm bandwidth with average noise figure of 10dB (approx.). Gain saturation effects beyond -20dBm/channel signal level and, gain spectra at different pump powers and amplifier lengths have also been studied. Full Text: PDF References Robert E. Tench, Proc. IEEE Elecronic Componenets and Technology Conference. 9, (1999). J. F. Massicott, R. Wyatt, and B. J. Ainslie, "Low noise operation of Er 3+ doped silica fibre amplifier around 1.6 ?m", Electron. Lett. 28, 1924 (1992). CrossRef Y. Sun, A. Srivastava, J.Zhou, and J. Sulhoff, "Optical fiber amplifiers for WDM optical networks", Bell Labs Technical Journal. 4, (1999) CrossRef H. Ono, M. Yamada and Y. Ohishi, "Gain-flattened Er/sup 3+/-doped fiber amplifier for a WDM signal in the 1.57-1.60-?m wavelength region", IEEE Photon. Technol. Lett. 9, (1997). CrossRef C. Jiang, W. Hu, Q. Zeng and S. Xiao, "High detectivity GaInAs-InP quantum-well infrared photodetectors grown on Si substrates", IEEE Photon. Technol. Lett. 14, 290 (2002). CrossRef M. A. Mahdi, F. R. M. Adikan, P. Poopalan, S. Selvakennedy, W. Y. Chan, and H. Ahmad, "Long-wavelength EDFA gain enhancement through 1550 nm band signal injection", Opt. Commnun.175, 296 (2000). CrossRef H. Chen, M. Leblanc and G.W. Schinn, "Gain enhanced L-band optical fiber amplifiers and tunable fiber lasers with erbium-doped fibers", Opt. Comm. 216, 119 (2003). CrossRef M. A. Mahdi and H. Ahmad, "Gain enhanced L-band Er/sup 3+/-doped fiber amplifier utilizing unwanted backward ASE", IEEE Photon. Technol. Lett. 13, 1067 (2001). CrossRef S. W. Harun, N. Tamchek, P. Poopalan and H. Ahmad, "Gain clamping in two-stage L-band EDFA using a broadband FBG", IEEE Photon. Technol. Lett. 16, 422 (2004). CrossRef T. Sakamoto. "Wide wavelength band (1535?1560 nm and 1574?1600 nm), 28 × 10 Gbit/s WDM transmission over 320 km dispersion-shifted fibre", Electron. Lett.34, 392 (1998). CrossRef Y. Sun et al., "80 nm ultra-wideband erbium-doped silica fibre amplifier", Electron. Lett. 33,1965 (1997). CrossRef T. Kasamatsu, Y. Tano and T. Ono, 13, 31 (2001). S. K. Liaw and Y. K. Chen, "Self-phase modulation coefficient of multiple-quantum-well optical amplifiers", IEEE Photon. Tech. Lett. 8, 876 (1996). CrossRef A. Srivastava and Y. Sun, Optical Fiber Telecommunications, I. P. Kaminov and T. Li, Eds. (San Diego, CA: Academic 2002, vol. VI A). R. Anthony and S.N. Biswas, "Temperature Dependent Gain Analysis of a Cascaded C-Band EDFA DWDM Network", Elseviers Procedia Technol. 4, 92 (2012). CrossRef G. Luo, J. L. Zyskind, I. A. Nagel, and M. A. Ali, "Experimental and theoretical analysis of relaxation-oscillations and spectral hole burning effects in all-optical gain-clamped EDFA's for WDM networks", IEEE J. Lightwave Technol. 16, 527 (1998). CrossRef I.K. Bu Sohn and J.W. Song, "Gain flattened and improved double-pass two-stage EDFA using microbending long-period fiber gratings", Optical Communications. 236, 141 (2004). CrossRef R. Singh, Sunanda and E.K. Sharma, "Gain flattening by long period gratings in erbium doped fibers", Optical Communications. 240, 123 (2004). CrossRef

Fourier-matching pseudospectral modal method for diffraction gratings: comment

Recently two variants of a pseudospectral modal method were developed for analyzing lamellar diffraction gratings: [J. Lightwave Technol. 27, 5151 (2009)] and [J. Opt. Soc. Am. A 28, 613 (2011)]. Both of them divide the computational domain into nonoverlapping subdomains and replace the spatial derivative in the Helmoltz equation by a differentiation matrix at the Chebyshev collocation points. The authors of the second reference claim that their method is more robust and accurate because they match the Fourier coefficient at the interfaces between the layers and drop some computed eigenmodes. We challenge these two ideas. Instead, we numerically demonstrate that by keeping all computed eigenmodes and by also numerically computing eigenmodes in homogeneous regions, the pseudospectral method performs better.

Lyot depolarizer in terms of the theory of coherence—description for light of any spectrum

A coherence-based description of the Lyot depolarizer illuminated by polychromatic light of any spectral density distribution is proposed as a generalization of the formulas provided for symmetrical spectra by Burns [J. Lightwave Technol. 1, 475 (1983)] and Mochizuki [Appl. Opt. 23, 3284 (1984)]. The structure of the derived expressions is explained in physical terms, and a numerical comparison with the previous solutions is performed. The results of the numerical analysis show that the proposed description, when applied to any configuration of a two-segment anisotropic depolarizer, is fully equivalent with the Mueller-Stokes calculus for broadband light. Following this consistency, the range of accuracy of the formula by Mochizuki has been verified.

Design of CWDM multiplexers based on series coupled ring resonators: analysis, potential and prospects on MEMS fabrication technologies

New designs for a 1 × 4 and a 1 × 8 CWDM multiplexers based on cascaded groups of series coupled ring resonators (Little et al. in J Lightwave Technol 15:998–1005, 1997; IEEE Photon Technol Lett 10:2263–2265, 2004; Hryniewicz et al. in IEEE Photon Technol Lett 12:320–322, 2000) are presented. Compared to other integrated optical alternatives such as MMI phasars (Paiam and MacDonald in Appl Opt 36: 5097–5108, 1997), cascaded Mach–Zehnder interferometers (Wang and He in J Lightwave Technol 23:1284–1290, 2005) and cascaded AWG (Dragone in IEEE Photon Technol Lett 3:812–815, 1991; Uetsuka in IEEE J Sel Top Quant Electron 10:393–402, 2004), the proposed circuits offer superior performance in their very sharp roll-off factor that exceeds 0.75, their reduced crosstalk level that lies below −60 dB and their negligible insertion loss for the 1 × 4 design. For the 1 × 8 design, the worst case insertion loss is 4 dB. However, the performances obtained exhibit passband ripples in the order of 5 dB, and besides, they are not very tolerant to fabrication errors. Being designed for SOI technology, the proposed circuits are compact as the circuit areas are 130 × 130 and 90 × 150 μm2 for the 1 × 4 and 1 × 8 designs, respectively. They also have a high potential for MEMS tunability.

Investigation on interchannel crosstalk at ADM for an optical ring network

In this paper, we investigated the effect of interchannel crosstalk at ADM of a ring network at sweeping bandwidth of filters. Analysis has been done in a ring network [G.P. Agrawal, Fiber Optic Communication System, Wiley-interscience, New York, 1997; Tim Gyselings et al., Crosstalk analyses of multi-wavelength optical cross connects, J. Lightwave Technol. 17 (1999) 1273; R. Ramaswami, K.N. Sivarajan, Optical Networks: A Practical Perspective, Morgan Kaufmann, Los Altos, CA, 1998] that contains four nodes communication signal over two channels at 1552.2 nm. At the bit rate of 10 Gbps, ADMs at each node is modeled by using WDM add and WDM drop components. The distance between nodes is taken 12.5 and 25 km and an ideal amplifier is inserted just before one of the node to compensate for the total fiber loss in the ring. Dispersion and nonlinear effects of fibers are disabled to observe the crosstalk effect of ADM at sweeping bandwidth from 10 to 40 GHz of fourth-order Bessel filters.

Comprehensive modelling of resonant‐cavity light‐emitting diode

We extended the theory by Henry (J. Lightwave Technol. LT-4, 288 (1986) [1]) to accurately treat the coupling of spontaneous emission noise with microcavity modes. The Green's function method is employed to solve the inhomogeneous wave equation including a Langevin force Fω which accounts for spontaneous emission by carriers at angular frequency ω. The optical wave equation is coupled with the self-consistent calculations of the material spontaneous emission rate of quantum well/dot using envelope wavefunction method. Finally the carrier transport equations are solved within the framework of 2D/3D drift-diffusion model implemented in the Crosslight Software package APSYS (Crosslight APSYS User's Manuals, Copyright © Crosslight Software Inc. (version 2005. 11) [2]). (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Buffer analysis with finite number of tunable receivers in WDM passive star networks

This study develops a performance model as an expansion of the receiver collision analysis presented in [I.E. Pountourakis, Performance evaluation with receiver collisions analysis in very high-speed optical fiber local area networks using passive star topology, J. Lightwave Technol. 16 (12) (1998) 2303–2310] for WDM networks. By theoretical analysis we estimate the receiver collision phenomenon and evaluate the performance measures and the rejection probability at destination for finite number of tunable receivers. Receiver collision analysis makes the performance behavior more realistic and expands the original analysis.

Experimental Measurements and Behavioral Modeling of an Electrostatically Actuated Bi-Axial Micromirror

Recent developments in micro-electro-mechanical systems and micromachining technologies have made possible the development and integration of micromirrors that can be employed for a number of consumer applications such as free space optical switching (Syms in J Lightwave Technol 20(7):1084–1094, 2002; Pan in Micromech Microeng 14(1):129–137, 2004), 2D scanning or image projection (Texas Instruments DLP http://www.dlp.com/). This high level of integration provides many advantages such as reproductivity and improved performance. Obviously, these increased levels of miniaturization raise new characterization and modeling concerns. We present in this paper the design, the fabrication process, the characterization and the behavioral modeling approach of a novel electrostatically actuated bi-axial micromirror. This micro-opto-electro-mechanical system is a result of a joint development between our partners Colibrys and Coventor companies (Colibrys http://www.colibrys.com/ ; Coventor http://www.coventor.com/). In the field of this work, two HDL multi-physics models using Verilog-A language and Matlab have been developed and validated by different experimental measurements.

Experimental measurements and behavioral modeling of an electrostatically actuated bi-axial micromirror

Recent developments in micro-electro-mechanical systems and micromachining technologies have made possible the development and integration of micromirrors that can be employed for a number of consumer applications such as free space optical switching (Syms in J Lightwave Technol 20(7):1084–1094, 2002; Pan in Micromech Microeng 14(1):129–137, 2004), 2D scanning or image projection (Texas Instruments DLP http://www.dlp.com/). This high level of integration provides many advantages such as reproductivity and improved performance. Obviously, these increased levels of miniaturization raise new characterization and modeling concerns. We present in this paper the design, the fabrication process, the characterization and the behavioral modeling approach of a novel electrostatically actuated bi-axial micromirror. This micro-opto-electro-mechanical system is a result of a joint development between our partners Colibrys and Coventor companies (Colibrys http://www.colibrys.com/ ; Coventor http://www.coventor.com/). In the field of this work, two HDL multi-physics models using Verilog-A language and Matlab have been developed and validated by different experimental measurements.

Analytical solution of the fundamental space filling mode of photonic crystal fibers

Analytical solution of the fundamental space filling mode of photonic crystal fibers is revisited based on previous results by Midrio et al. [J Lightwave Technol 2000;18(7):1031–7]. The fundamental space filling mode is designated HE 11 mode following the conventional mode classification. A comparison is made between the vectorial method and the scalar method when identical parameters are used in the analytical solution. A more accurate radius of the equivalent circular unit cell is determined.

Quasi-analytic formalism for mode characteristics in highly overmoded rectangular dielectric waveguide bends

A fast and simple quasi-analytic method to simulate mode characteristics in highly overmoded rectangular dielectric waveguide bends is presented. Fast mode-based bend models are necessary, since overmoded rectangular waveguides have become very popular in optical interconnects on printed circuit boards. The proposed method combines a simple mode solver with the formalism that was proposed by Melloni et al. [J. Lightwave Technol. 16, 571 (2001)], yielding to a very convenient and accurate quasi-analytic formalism for the bend transfer function based on matrix notation. For that purpose, a simple method to approximate leaky modes is introduced. The model offers the ability to predict individual modal phases and amplitudes within a given bend as well as the calculation of coupling losses and was validated using three-dimensional beam-propagation-method simulation software.

Analysis of a rapidly reconfigurable multicast capable photonic switched interconnect

We present a complete mathematical formalism for a rapidly reconfigurable gated timeslot tuner based on a serial feed-forward structure. This gated serial timeslot tuner has been a key component for various demonstrations including a 100 Gb/s photonic switched interconnect [K.-L. Deng, R.J. Runser, P. Toliver, I. Glesk, P.R. Prucnal, J. Lightwave Technol. 18 (2000) 1892]. Design constraints for the proper operation of the interconnect are developed. Methods to predict feasible multicast combinations and control patterns required for driving the timeslot tuner are presented in terms of a two-dimensional (2D) contour map.

Propagation delay latency and a data channel collision avoidance protocol

In this paper, we study the effect of the round trip propagation delay on performance measures of wavelength division multiplexing (WDM) networks. Even though the impact of propagation delay is substantial in the optical network’s behavior, most of the studies ignore the effect of this time component in throughput evaluation. We consider the same network architecture as it described [J. Lightwave Technol. 8 (1990) 520] and exploit the long propagation delay of WDM networks to develop a simple multiple access algorithm improving the system utilization. We suppose infinite population and adopt the “tell and wait” policy to access to the system.

Theoretical expression for change of extraordinary refractive index in annealed proton exchanged LiNbO 3 optical waveguides

A general expression for the change in extraordinary refractive index of the annealed proton exchanged LiNbO 3 waveguide has been deduced. The expression deduced explains the experimental results of decrease in change of extraordinary refractive index with annealing. The effect of annealing time has also been incorporated following Cao's model (Cao, Ramaswamy, Srivastava, J. Lightwave Technol. 10 (1992) 1302–1313). The concentration profile of protons in the annealed waveguide has been deduced theoretically, which is consistent with the previous results. The spontaneous polarization has been considered as the central mechanism for change in extraordinary refractive index due to proton exchange with annealing.