Results 251 to 260 of about 10,599,323 (287)

Long-period gratings in planar optical waveguides

Applied Optics, 2002
We present a theoretical analysis of light propagation in a four-layer planar waveguide that consists of a long-period grating (LPG) having a period of the order of 100 microm. By means of the coupled-mode theory, we show that such a structure is capable of coupling light from the fundamental guided mode to the cladding modes at specific wavelengths ...
Vipul, Rastogi, Kin Seng, Chiang
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Electronically reconfigurable superimposed waveguide long-period gratings

Journal of the Optical Society of America A, 2002
The perturbation to the refractive index induced by a periodic electric field from two systems of interdigitated electrodes with the electrode-finger period l is analyzed for a waveguide with an electro-optically (EO) active core-cladding. It is shown that the electric field induces two superimposed transmissive refractive-index gratings with different
Mykola, Kulishov, Xavier, Daxhelet, Mounir, Gaidi, Mohamed, Chaker   +3 more
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Sensitivity enhancement of long period gratings for temperature measurement using the long period grating pair technique

Sensors and Actuators A: Physical, 2008
Abstract An approach to enhance the sensitivity achievable with long period grating (LPG) technology for temperature measurement, by using a LPG pair technique to create Mach-Zehnder interferometers written into B–Ge co-doped optical fibres, is presented.
Samer K. Abi Kaed Bey, Tong Sun, Kenneth T.V. Grattan   +2 more
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Long-period fiber grating sensors

Optical Fiber Communications, OFC., 2005
Summary form only given. We propose novel long-period grating-based optical fiber sensors that possess high sensitivities and simple demodulation schemes, and can be easily configured for multiparameter measurements.
V. Bhatia, M.K. Burford, K.A. Murphy, A.M. Vengsarkar   +3 more
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Long-period gratings as an ASE suppressor

SPIE Proceedings, 1998
Long-period grating (LPG) is the transmission type grating, that light is coupled from the LP 01 mode to forward-propagation cladding modes LP lm , thus providing the function of wavelength dependent losses in optical fiber systems. We design a wavelength selective grating filter with transmission loss -21.2 dB at wavelength of 1531 nm, which can be ...
Yeong Her Chen, Lin-Gen Sheu, Ching Chung Yang, I-Wen Wei, Win C. Lin, Yen Zen Lee, Chung Ho Hsia   +6 more
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Polymeric long-period waveguide gratings

IEEE Photonics Technology Letters, 2003
A long-period waveguide grating (LPWG) was demonstrated in a polymeric waveguide fabricated on an SiO/sub 2/-Si substrate using standard cleanroom fabrication processes: ultraviolet photolithography and reactive ion etching. Experimental results confirm that the relationship between the transmission peak wavelength and the grating period is linear. The
H.C. Tsoi, W.H. Wong, E.Y.B. Pun
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Long-period-grating waveguide filters

2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666), 2004
This paper reports the fabrication of long period grating (LPG) filters in ion-exchanged BK7-glass waveguides and benzocyclobutene (BCB) polymer waveguides to show that LPG filters can be fabricated with different techniques and materials. The structure of corrugated LPG and its normalised transmission spectrum is analysed.
K.S. Chiang, K.P. Lor, C.K. Chow, H.P. Chan, V. Rastogi, Y.M. Chu   +5 more
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Development of long-period fiber grating coupling devices

Applied Optics, 2008
A long-period fiber grating (LPFG) formed in a single-mode fiber is considered as an effective device to tap light from the core of fiber. This light-tapping property of the LPFG allows a new class of wavelength-selective optical couplers to be realized by using the configuration of parallel LPFGs. Over the years a number of four-port and six-port LPFG
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Ultra-long-period fiber gratings

Proceedings 27th European Conference on Optical Communication (Cat. No.01TH8551), 2002
We report here for the first time the fabrication and characterisation of long period fiber gratings with periods of several millimetres. The resonant loss peaks of these gratings are generated from the coupling of the forward propagating guided core mode to the cladding modes of fundamental and harmonic orders.
null Xuewen Shu, B. Gwandu, L. Zhang, I. Bennion   +3 more
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Effects of chirp in long period gratings

Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, 1999
Long period gratings (LPG) offer coherent coupling between two co-propagating modes in a fiber, and are very attractive due to their ability to shape the optical spectrum1 over large wavelength ranges.
Siddharth Ramachandran, Jefferson Wagener, Rolando Espindola, Thomas Strasser   +3 more
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