A single-mode polymer optical fiber （POF） with highly photosensitive core doped with benzil dimethyl ketal （BDK） is fabricated and used for writing Bragg grating through the two-beam interference method. The Bragg...A single-mode polymer optical fiber （POF） with highly photosensitive core doped with benzil dimethyl ketal （BDK） is fabricated and used for writing Bragg grating through the two-beam interference method. The Bragg wavelength of the grating is about 1570 nm, while the full-width at half-maximum （FWHM） of the reflection peak is 0.3 nm. The temperature response of POF Bragg grating is theoretically analyzed and experimentally measured in contrast to silica optical fiber Bragg grating （FBG）. The result shows that the temperature character of POF Bragg grating is negative, which is opposite to the silica optical FBG. The absolute value of the temperature response of POF Bragg grating is one order of magnitude higher than that of the silica optical FBG, making POF Bragg grating appear to be very attractive for constructing temperature sensors with high resolution.展开更多
A method to fabricate fiber Bragg grating （FBG） in an optical microfiber （OM） from a conventional photosensitive fiber is proposed in this letter. The cladding of a conventional photosensitive fiber is etched to 1...A method to fabricate fiber Bragg grating （FBG） in an optical microfiber （OM） from a conventional photosensitive fiber is proposed in this letter. The cladding of a conventional photosensitive fiber is etched to 17 pro. The etched fiber is drawn to an OM 6μm in diameter. The photosensitivity of the fabricated OM is effectively reserved. A FBG in the OM （MFBG） is successfully fabricated using a KrF excimer laser at a fluence of 400 mJ/cm2 through a phase mask with a pitch of 1 089.3 nm. The reflectivity of the FBG is approximately 10%, and the 3-dB spectrum bandwidth is 0.13 nm. The concentration of brine is measured by immersing the MFBG in the liquid, and the minimum detectable refractive index variation can reach 7.2×10^-5 at a refractive index value of 1.33.展开更多
The highly Ge-doped photosensitive fiber （PSF） has been widely used in the fabrication of fiber Bragg gratings （FBGs）. Its birefringence and cladding mode coupling characteristics greatly influence FBG＇s transmis...The highly Ge-doped photosensitive fiber （PSF） has been widely used in the fabrication of fiber Bragg gratings （FBGs）. Its birefringence and cladding mode coupling characteristics greatly influence FBG＇s transmission feature in communication application areas. In this work, a new concept of the PSF is introduced which, along with an optimized birefringence design, a precisely controlled fabrication process, and a cladding mode depressed design, results in a written FBG with -25-dB clad mode-depressed ratio and a polarization mode dispersion value less than 0.045 ps.展开更多
Sn/Yb codoped silica optical fiber preform is prepared by the modified chemical vapor deposition （MCVD） followed by the solution-doping method. Ultraviolet （UV） optical absorption, photoluminescence （PL） spectra...Sn/Yb codoped silica optical fiber preform is prepared by the modified chemical vapor deposition （MCVD） followed by the solution-doping method. Ultraviolet （UV） optical absorption, photoluminescence （PL） spectra under 978-nm laser diode （LD） pumping, and refractive index change after exposure to 266-nm laser pulses are obtained. There is only a little change in the PL spectra while a positive refractive index change up to 2×10^-4 is observed after 30-min exposure to 266-nm laser pulses. The results show that both of the peculiar photosensitivity of Smdoped silica and the gain property of Yb-doped silica fiber are preserved in the Sn/Yb codoped silica optical fiber preform. The experimental data suggest that the photosensitivity of the fiber preform under high energy density laser irradiation should be mainly due to the bond-breaking of oxygen deficient defects, while under relatively low energy density laser irradiation, the refractive index change probably originates from the photoconversion of optically active defects.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 50703038, 50773075,21074123, and 50973101)the Chinese Academy of Sciences (Nos. kjcx3.syw.H02 and kjcx2-yw-m11)+1 种基金China Postdoctoral Science Foundation (No. 20100470038)the "Hundred Talents Program" of the Chinese Academy of Sciences
文摘A single-mode polymer optical fiber （POF） with highly photosensitive core doped with benzil dimethyl ketal （BDK） is fabricated and used for writing Bragg grating through the two-beam interference method. The Bragg wavelength of the grating is about 1570 nm, while the full-width at half-maximum （FWHM） of the reflection peak is 0.3 nm. The temperature response of POF Bragg grating is theoretically analyzed and experimentally measured in contrast to silica optical fiber Bragg grating （FBG）. The result shows that the temperature character of POF Bragg grating is negative, which is opposite to the silica optical FBG. The absolute value of the temperature response of POF Bragg grating is one order of magnitude higher than that of the silica optical FBG, making POF Bragg grating appear to be very attractive for constructing temperature sensors with high resolution.
文摘A method to fabricate fiber Bragg grating （FBG） in an optical microfiber （OM） from a conventional photosensitive fiber is proposed in this letter. The cladding of a conventional photosensitive fiber is etched to 17 pro. The etched fiber is drawn to an OM 6μm in diameter. The photosensitivity of the fabricated OM is effectively reserved. A FBG in the OM （MFBG） is successfully fabricated using a KrF excimer laser at a fluence of 400 mJ/cm2 through a phase mask with a pitch of 1 089.3 nm. The reflectivity of the FBG is approximately 10%, and the 3-dB spectrum bandwidth is 0.13 nm. The concentration of brine is measured by immersing the MFBG in the liquid, and the minimum detectable refractive index variation can reach 7.2×10^-5 at a refractive index value of 1.33.
文摘The highly Ge-doped photosensitive fiber （PSF） has been widely used in the fabrication of fiber Bragg gratings （FBGs）. Its birefringence and cladding mode coupling characteristics greatly influence FBG＇s transmission feature in communication application areas. In this work, a new concept of the PSF is introduced which, along with an optimized birefringence design, a precisely controlled fabrication process, and a cladding mode depressed design, results in a written FBG with -25-dB clad mode-depressed ratio and a polarization mode dispersion value less than 0.045 ps.
基金supported by the National Natural Science Foundation of China (Nos. 10074011 and 60378034)the Ministry of Science and Technology of China (Nos. 02JD14001 and 03DJ14001).
文摘Sn/Yb codoped silica optical fiber preform is prepared by the modified chemical vapor deposition （MCVD） followed by the solution-doping method. Ultraviolet （UV） optical absorption, photoluminescence （PL） spectra under 978-nm laser diode （LD） pumping, and refractive index change after exposure to 266-nm laser pulses are obtained. There is only a little change in the PL spectra while a positive refractive index change up to 2×10^-4 is observed after 30-min exposure to 266-nm laser pulses. The results show that both of the peculiar photosensitivity of Smdoped silica and the gain property of Yb-doped silica fiber are preserved in the Sn/Yb codoped silica optical fiber preform. The experimental data suggest that the photosensitivity of the fiber preform under high energy density laser irradiation should be mainly due to the bond-breaking of oxygen deficient defects, while under relatively low energy density laser irradiation, the refractive index change probably originates from the photoconversion of optically active defects.
