Characterization of a dissolved oxygen sensor made of plastic optical fiber coated with ruthenium-incorporated solgel

A dissolved oxygen sensor made of plastic optical fiber as the substrate and dichlorotris (1, 10-phenanthroline) ruthenium as a fluorescence indicator is studied. Oxygen quenching characteristics of both intensity and phase were measured; the obtained characteristics showed deviation from the linear relation described by the Stern-Volmer equation. A two-layer model is proposed to explain the deviation, and main parameters can be deduced with the model. (C) 2009 Optical Society of America

Repetition rate stabilization of the SBS Q-switched fiber laser by external injection

Repetition rate fluctuation is one of the main drawbacks of the low-threshold stimulated Brillouin scattering (SBS) Q-switched fiber laser. A method to stabilize the repetition rate is proposed in this paper by injecting a square-wave modulated light. It is measured experimentally that variance of the repetition rate can be improved from similar to 20% to similar to 1% of the period. It is also found that effectiveness of the method depends on modulation frequency and duty cycle of the injection. Its working mechanism is analyzed qualitatively. (C) 2009 Optical Society of America

Study of polymer thermal and mechanical properties using a fiber Bragg grating thermal sensor

A simple and practical method for the study of polymer thermal and mechanical properties using a fiber Bragg grating (FBG) sensor is presented for the first time, in which the FBG is embedded in a typical epoxy polymer. By measuring the sensitivity change of the FBG sensor, changes of the thermal-mechanical properties of the polymer with temperature and pressure can be measured. The experimental results show that this technique is capable of providing continuous in-line monitoring such properties with high sensitivity during transformation between the glassy state and the rubbery state of a polymer within the temperature and pressure range of 20 to 180 C and 0 to 15 MPa. (c) 2007 Society of Photo-Optical Instrumentation Engineers.

Study of polymer thermal and mechanical properties using a fiber Bragg grating thermal sensor

A simple and practical method for the study of polymer thermal and mechanical properties using a fiber Bragg grating (FBG) sensor is presented for the first time, in which the FBG is embedded in a typical epoxy polymer. By measuring the sensitivity change of the FBG sensor, changes of the thermal-mechanical properties of the polymer with temperature and pressure can be measured. The experimental results show that this technique is capable of providing continuous in-line monitoring such properties with high sensitivity during transformation between the glassy state and the rubbery state of a polymer within the temperature and pressure range of 20 to 180 C and 0 to 15 MPa. (c) 2007 Society of Photo-Optical Instrumentation Engineers.

Field and dispersion properties of subwavelength-diameter hollow optical fiber

We have investigated the basic properties of subwavelength-diameter hollow optical fiber with exact solutions of Maxwell's equations. The characteristics of modal field and waveguide dispersion have been studied. It shows that the subwavelength-diameter hollow optical fibers have interesting properties, such as enhanced evanescent field, local enhanced intensity in the hollow core and large waveguide dispersion that are very promising for many miniaturized high performance and novel photonic devices. (C) 2007 Optical Society of America.

Stable single frequency and single polarization DFB fiber lasers operated at 1053 nm

Stable single-frequency and single-polarization distributed-feedback (DFB) fiber laser was realized by giving a pressure on the phase shift region of the fiber grating. The output wavelength of the DFB fiber laser is 1053 nm. When the pump power of 980 nm laser diode is 100 and 254 mW, the output power can reach 8.3 and 37.1 mW and the polarization extinction ratio was 26 and 20 dB, respectively. After chopped by Acousto-optic modulator (0.3 Hz), the pulse peak value variance is 4.65%(peak to peak) and 1.098% (RMS) for 31 min. (C) 2006 Elsevier Ltd. All rights reserved.

Field enhancement and power distribution characteristics of subwavelength-diameter terahertz hollow optical fiber

Fields in subwavelength-diameter terahertz hollow optical fiber (STHOF) can be intensified by large discontinuity of the electric field at high index contrast interfaces. The influences of fiber geometry and refractive index of the dielectric region on the fiber characteristics, such as power distribution, enhancement factor, have been discussed in detail. By appropriate design, the intensity in the central region of STHOF may be enhanced by a factor of greater than 1.5 compared with subwavelength-diameter terahertz fiber without the central hole and the loss can be reduced. For its compact structure and simple fabrication process, the fiber may be very useful in many miniaturized high performance and novel terahertz photonic devices. (c) 2007 Elsevier B.V. All rights reserved.

75 mW robust single frequency Yb-doped DFB fiber Bragg grating laser

Incorporating the shielded method and post-processing method, a 75 mW single frequency Yb-doped DFB fiber laser was obtained with a 250 mW laser diode pump source at 978 nm. The threshold of the laser is 2 mW. The laser is single-polarization operation and the output power fluctuation is less than 0.2 mW in one hour when the pump power is 250 mW.

7.3 W国产单频光纤放大器

报道了一种MOPA式国产单频光纤放大器。该放大器采用连续波单频激光器作为主振荡器，采用我国自行设计和制造的大模场面积掺Yb双包层光纤作为功率放大器，在波长1064 nm处实现了最高7.3 W的连续激光输出，斜率效率为39%，光－光转换效率为26%。此外，对光谱特性及放大的自发发射的抑制也进行了探讨。