Electro-optical switch and continuously tunable filter based on a Bragg grating in a planar waveguide with a liquid crystal overlayer

The possibility of using smectic liquid crystals in active wave- guide devices is explored through the analysis of both an integrated electro-optic switch and a continuously tunable filter. The two devices are based on a Bragg grating in planar waveguide with a liquid crystal over- layer, which enables changing the spectral behavior of the device. The fast and bistable switching of smectic C* in the surface-stabilized liquid crystal structure is used to investigate the possibility of realizing an inte- grated electro-optical switch. The principal advantage of this device is its spectral signature, which enables us to overcome the problems of inten- sity dependent devices. The soft-mode of smectic A* liquid crystals, enabling a continuous modulation of extraordinary refractive index, is used to design an integrated wavelength filter in the wavelength range of interest for optical communications. The principal advantages of such device include fast tuning speed, wide tuning range, low power dissipa- tion, and low cost. © 2002 Society of Photo-Optical Instrumentation Engineers.

[1]  G. Righini,et al.  Fast Electro-Optical Switch Based on a Nematic Liquid Crystal Waveguide , 2001 .

[2]  G. Righini,et al.  Electro-Optic Modulation of Light by a Planar Waveguide Based on Ferroelectric Liquid Crystals , 2000 .

[3]  Luigi Sirleto,et al.  Nonlinear optical propagation in dye-doped liquid crystal waveguides , 1999 .

[4]  Min-Cheol Oh,et al.  Tunable wavelength filters with Bragg gratings in polymer waveguides , 1998 .

[5]  G. Righini,et al.  Integrated Electro-Optic Switch Based on a Ferroelectric Liquid Crystal Waveguide , 1998 .

[6]  S. Najafi,et al.  Sol-gel glass waveguide and grating on silicon , 1998 .

[7]  J. R. Sambles,et al.  Optical guided mode studies of the director structure in FLC cells , 1998 .

[8]  K.M. Johnson,et al.  High-speed liquid crystal fiber Fabry-Perot tunable filter , 1996, Optical Fiber Communications, OFC..

[9]  Kristina M. Johnson,et al.  High-speed continuously tunable liquid crystal filter for WDM networks , 1996 .

[10]  Thomas K. Gaylord,et al.  Ferroelectric liquid-crystal waveguide modulation based on a switchable uniaxial-uniaxial interface. , 1996, Applied optics.

[11]  Wei-Ching Chuang,et al.  SSFLC optical directional coupler switch with a short device length: a proposal , 1995 .

[12]  Y. Silberberg,et al.  Liquid crystal and grating-based multiple-wavelength cross-connect switch , 1995, IEEE Photonics Technology Letters.

[13]  K.M. Johnson,et al.  High-speed wavelength tunable liquid crystal filter , 1995, IEEE Photonics Technology Letters.

[14]  Steve J. Elston,et al.  The Optics of Ferroelectric Liquid Crystals , 1995 .

[15]  K M Johnson,et al.  High-speed analog refractive-index modulator that uses a chiral smectic liquid crystal. , 1994, Optics letters.

[16]  Mario Bertolotti,et al.  Advances in integrated optics , 1994 .

[17]  Rick L. Morrison,et al.  Practical applications of diffractive optics in free-space photonic switching networks , 1993, Optics + Photonics.

[18]  M. E. Motamedi.  Merging micro-optics with micromechanics: micro-opto-electro-mechanical (MOEM) devices , 1993, Optics + Photonics.

[19]  Masanori Ozaki,et al.  Leaky mode operation in FLC/waveguide modulator , 1993 .

[20]  N C Roberts.  Multilevel computer-generated holograms with separable phase functions for beam shaping. , 1992, Applied optics.

[21]  K A Winick,et al.  Effective-index method and coupled-mode theory for almost-periodic waveguide gratings: a comparison. , 1992, Applied optics.

[22]  Mark A. Handschy,et al.  Surface‐stabilized ferroelectric liquid‐crystal electro‐optic waveguide switch , 1990 .

[23]  M. A. Saifi,et al.  Electrically tunable optical filter for infrared wavelength using liquid crystals in a Fabry–Perot étalon , 1990 .

[24]  Masanori Ozaki,et al.  Fast Optical Switching in Polymer Waveguide Using Ferroelectric Liquid Crystal , 1990 .

[25]  Lachezar Komitov,et al.  Device physics of the soft‐mode electro‐optic effect , 1989 .

[26]  Wojciech Kuczynski,et al.  Submicrosecond electro‐optic switching in the liquid‐crystal smectic A phase: The soft‐mode ferroelectric effect , 1987 .

[27]  N. Clark,et al.  Submicrosecond bistable electro‐optic switching in liquid crystals , 1980 .

[28]  Amnon Yariv,et al.  Periodic structures for integrated optics , 1977 .