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991.
In this Letter, an electro-optical probe configuration with polar molecule liquids as the sensing film is proposed to improve the voltage sensitivity. This method exhibited increases in intrinsic sensitivities better than 0.1 mV/√Hz, 2 orders of magnitude larger than the normal method using a GaAs probe in the same measurement system. Based on the mechanism of orientation polarization, the electro-optic coefficient was measured to be 250 pm/V by the Teng-Man method at a modulation field of 100 Hz. This technology will be promising in applications of low-frequency field detection. 相似文献
992.
Accurate method for measuring the thermal coefficient of group birefringence of polarization-maintaining fibers 总被引:1,自引:0,他引:1
We present a method to accurately measure the group birefringence variation with temperature in high-birefringence polarization-maintaining (PM) fibers using a distributed polarization analyzer. By analyzing polarization cross-talk peaks purposely induced at both ends of a PM fiber, the temperature coefficient of group birefringence can be accurately obtained. We confirm the theoretical prediction that the group birefringence of PANDA and TIGER PM fibers decrease linearly with temperature from -40 °C to 80 °C, and find that the temperature coefficients are -5.93 × 10(-7) °C(-1) and -5.29 × 10(-7) °C(-1) for two types of PANDA fibers, and -5.36 × 10(-7) °C(-1) for a TIGER fiber. 相似文献
993.
Focused proton beam writing has been utilized to fabricate optical channel waveguides in Nd:GGG crystals. The 1?MeV proton beam irradiation creates a local modified region with positive refractive index changes at the end of the proton trajectory, in which the channel waveguide could confine the light field in a symmetric way. Room-temperature laser emission has been achieved at 1063.7?nm, with absorbed pump power of 61?mW (at 808?nm). The obtained slope efficiency of the Nd:GGG waveguide laser system is as high as 66%, which is, to our best knowledge, the highest value for integrated lasers from ion beam processed channel waveguide systems. 相似文献
994.
Using freshly isolated animal retinas, we have conducted a series of experiments to test fast intrinsic optical signals (IOSs) that have time courses comparable to electrophysiological kinetics. In this Letter, we demonstrate the feasibility of in vivo imaging of fast IOSs in intact frogs. A rapid line-scan confocal ophthalmoscope was constructed to achieve high-speed IOS recording. By rejecting out-of-focus background light, the line-scan confocal imager provided the resolution to differentiate individual photoreceptors in vivo. Rapid confocal imaging disclosed robust IOSs with time courses comparable to retinal electroretinogram kinetics. High-resolution IOS images revealed both positive (increasing) and negative (decreasing) light responses, with subcellular complexity. 相似文献
995.
We demonstrate a terahertz-wave parametric oscillator (TPO) with a corner-cube resonator consisting of a corner-cube prism (CCP) and a flat mirror. By using the cavity configuration proposed in this Letter, the generation of tunable monochromatic terahertz (THz) waves can be achieved just by rotating the flat mirror instead of rotating the TPO cavity relative to the pump beam. The THz-wave output intensity and pulse width can be controlled periodically by rotating the CCP around the cavity axis. The TPO stability against cavity misalignment is significantly improved by at least 1 to 2 orders of magnitude compared with the conventional plane-parallel resonator configuration. 相似文献
996.
An efficient 2 μm room temperature Ho:YVO(4) laser resonantly pumped by a 1.94 μm Tm:YAP laser is demonstrated, for the first time to our knowledge, in this Letter. Up to 8.58 W of laser output at 2053 nm is obtained with the optical-to-optical conversion efficiency as much as 41.2%. The output beam had quality of M2 factor with Mx(2) of 3.58 and My(2) of 1.76 at 8 W output level. In addition, we also obtained 4.18 W laser output at 2066 nm and 7.04 W at 2040 nm from the Ho:YVO(4) laser with conversion efficiency of 27.8% and 33.8%, respectively. 相似文献
997.
We propose a fiber laser that can operate with passive mode-locking pulse output, continuous single-wavelength emission, and continuous multiwavelength emission. It consists of a nonlinear optical loop mirror (NOLM) in a linear cavity. The NOLM is used to induce different kinds of intensity-dependent feedback, which determine the operation mode of the laser. We have experimentally demonstrated that the fiber laser can easily be switched between the operation modes. The results may find useful applications in optical communication and fiber sensing. 相似文献
998.
In this paper, we reported a novel, simple, and cost-effective route to SnTe films. The films were prepared by a chemical bath method, at room temperature and ambient pressure, using conventional chemicals as starting materials with or without surfactant. The films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and field-emission scanning electron microscopy, respectively. The SnTe film deposited without surfactant consists of nanoparticles (∼100 nm). The film deposited using polyethyleneglycol (PEG) as the surfactant consists of nanoparticles with size of ∼25 nm, whereas the film deposited using polyvinylpyrrolidone (PVP) as the surfactant consists of rough rod-like nanostructures (∼50 in diameter and ∼500 nm in length), besides nanoparticles (∼40-180 nm). The SnTe film deposited with PEG is smoother and denser. The formation mechanism of the SnTe films was proposed. 相似文献
999.
Z.P. FanW.L. Liu Z.J. WeiJ.S. Yao X.L. SunM. Li X.Q. Wang 《Applied Surface Science》2011,257(9):4296-4301
Two biomimetic superhydrophobic polymeric surfaces were obtained by a simple approach under ambient atmosphere. Water and ethanol were used as the nonsolvents in the method of phase separation in different systems. The influences of various factors in the process were investigated. Both of the as-prepared films showed excellent superhydrophobicity, depending on the high contact angle and the low contact angle hysteresis. Moreover, the classic and a new modified Cassie-Baxter relation were used on the polystyrene and poly-α-methyl styrene films to confirm the superhydrophobic performance. 相似文献
1000.