1,482 research outputs found
High-sensitivity mode-locked fiber laser gyroscope
No full textWe report significant performance improvement of a mode-locked fiber laser gyroscope. A Fabry-Perot cavity GaAlAs laser diode whose front facet was antireflection coated was used as a gain medium. The rms noise equivalent rotation rate measured with a time-interval counter was improved to 0.06 deg/root h. The long-term drift of the gyroscope signal was reduced to 100 deg/h after a polarizer was inserted into the laser cavity formed with a polarization-maintaining fiber. (C) 1997 Optical Society of AmericaThis research was supported by the Agency for
Defense Development, Korea
Phase sensitive detection for mode-locked fiber laser gyroscope
No full textWe demonstrate a significant improvement in the performance of a mode-locked fiber laser gyroscope by using a lock-in amplifier. We show that the direct output of the lock-in amplifier has a desirable linear dependence on the rotation rate and is insensitive to the intensity difference between two pulses that causes phase error in the time interval measurement. Two orders of magnitude improvement is demonstrated in the longterm stability compared to that from previously reported time interval measurement
An efficient synthetic method of ansa-zirconocene dimethyl complexes via Me2ZrCl2
No full textThe reaction of ZrCl4 with 2 equiv. of MeLi to form Me2ZrCl2 followed, by in situ metalation of Me2ZrCl2 with the corresponding ansa-ligands produces the respective ansa-dimethylzirconocene complexes, o-Xyl(Ind)(2)ZrMe2 [1b, Ind=eta(5)-1-indenyl, o-Xyl=C6H4(CH3)(2)-1,2], 2-Bn(Ind)(2)ZrMe2 [2b, 2-Bu=(-CH2CH=CHCH2-)], Et(Ind)(2)ZrMe2 (3b), and Me2Si(Znd)(2)ZrMe2 (4b) in high yields. Treatment of 1b-3b with HCl affords ansa-dichlorozirconocene complexes, 1a-3a, in quantitative yields. Synthesis of ansa-dimethylzirconocene via Me2ZrCl2 is more efficient than that via Cp2ZrCl2 (Cp-2=ansa-ligand) in the conventional methods. (C) 1997 Elsevier Science S.A
Dynamic erbium-doped fiber amplifier based on active gain flattening with fiber acoustooptic tunable filters
No full textWe describe the first demonstration of a dynamic erbium-doped fiber amplifier (EDFA) based on automatic feedback control of active gain equalizing filters. The filters are all-fiber acoustooptic tunable filters capable of generating controllable filter shapes. Wide dynamic-range gain/power control is achieved with <0.6-dB signal ripple over 30 mn in various operating conditions. We also show, by numerical simulation, an important advantage of the dynamic EDFA over a conventional EDFA in cascaded structures
Effects of the resistivity and crystal orientation of the silicon PIN detector on the dark current and radiation response characteristics
No full textPresident Hyun-Sik Chae of SF Technology Co.
Ltd. for assembling our detectors with amplifier circuit
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