1,721,098 research outputs found
All-fiber tunable filter and laser based on two-mode fiber
No full textWe demonstrate an all-fiber acousto-optic tunable filter based on two-spatial-mode coupling, with improved ruggedness and efficiency, by using a new acoustic-transducer design. We use a rigorous modeling of the flexural acoustic wave to analyze the mode coupling with better accuracy. Using the acousto-optic tunable filter, we demonstrate a novel all-fiber tunable laser with a tuning range of more than 20 nm and a linewidth of 0.2 nm. (C) 1996 Optical Society of Americ
Long-period fiber gratings based on periodic microbends
No full textWe demonstrate a new type of high-performance long-period fiber grating based on are-induced periodic microbends. The fabrication method is simple and does not require:special fibers. Flexibility in controlling the filter parameters makes it possible to produce arbitrary filter profiles by use of a simple apodization technique, which is difficult to do with conventional long-period gratings. (C) 1999 Optical Society of America. OCIS codes: 050.2770, 060.2330, 060.2340, 120.2440, 220.1230.This research was partially supported by the Opto-
Electronics Research Center, which is funded by the
Korea Science and Engineering Foundation, and by
Donam Systems, Inc
STRAIN EFFECTS ON 2-MODE FIBER GRATINGS
No full textThe spectral, interferometric, and polarization properties of mode-coupling fiber gratings under strain are described. The grating is formed by photosensitivity that uses modal interference in the two-mode fiber. Theoretical and experimental results show the possibilities of using the fiber grating for optical switches, tunable filters, interferometric sensors, and polarizers.This research was supported by the Agency for
Defense Development under contract 90-1-1
Interrogation of fiber grating sensor arrays with a wavelength-swept fiber laser
No full textWe demonstrate a novel application of a wavelength-swept fiber laser to fiber Bragg grating sensor-array interrogation. The laser provides high signal powers of >3 mW with <0.1-nm spectral resolution over a 28-nm wavelength span. Using time-interval counting, we demonstrate static-dynamic strain measurements with a resolution of 0.47 mu epsilon rms at a sampling rate of 250 Hz. (C) 1998 Optical Society of America.S. H. Yun acknowledges the financial support of
the Korea Research Foundation in program year 1997.
D. J. Richardson was supported by the Royal Society
under the provision of a Royal University Fellowship
All-fiber-optic nonreciprocal modulator
No full textA new all-fiber-optic nonreciprocal device using two acousto-optic frequency shifters is proposed and demonstrated. When the device was operated as an optical isolator, an extinction ratio of 22 dB was obtained. The device's unique modulation capability is also described. (C) 1997 Optical Society of America.This research was partially supported by the Opto-
Electronic Research Center which is funded by the
Korea Science and Engineering Foundation
All-fiber tunable comb filter with nonreciprocal transmission
No full textWe demonstrate an all-fiber nonreciprocal comb filter by using two acoustooptic frequency shifters and a two-mode fiber interferometer. The transmission spectra for two opposite optical propagation directions are both periodic functions of optical wavelength, but different in transmission peak wavelengths. Methods for controlling the spacing end position of the transmission peak wavelengths are demonstrated
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