Abstract-The terahertz metamaterials for sensitive biosensors in the detection of ethanol solutions

Author links open overlay panelFuyu Li, Ke He, Tingting Tang, Yinghui Mao, Rui Wang, Chaoyang Li, Jian Shen,

                                               

https://www.sciencedirect.com/science/article/abs/pii/S0030401820307045 

Metamaterials have attracted much attention due to their subwavelength characteristics, especially in the field of unlabeled refractive index sensing. Because biomolecular molecules have special biological fingerprint spectra in terahertz band, high sensitivity sensor components can be realized by using the special electromagnetic response of metamaterials. In this paper, a novel biosensor based on electromagnetic induced reflection is designed. We find that the asymmetrically fractured double-ring resonator can effectively enhance the fano-resonance of electromagnetic induction reflection, where the resonance position occurs at 1.57 THz. Oscillating Lorentz model shows that when the resonant detuning continues to increase, the bright mode and the dark mode are strongly coupled. When the light mode decreases, the radiation loss also decreases, which induces the decrease of resonance ability. The sensitivity of pure ethanol solution (analyte) under  coating thickness is 103.7 GHz/RIU, 107.1 GHz/RIU and 112.05 GHz/RIU, respectively. The sensitivity and full width at half maximum (FWHM) of the sensor are studied from the perspectives of analyte concentration, thickness, and proportion, respectively. The results show the great potential of electromagnetic metamaterials as sensitive sensors in biological solution detection.

Abstract-Terahertz oscilloscope for recording time information of ultrashort electron beams

Lingrong Zhao, Zhe Wang, Heng Tang, Rui Wang, Yun Cheng, Chao Lu, Tao Jiang, Pengfei Zhu, Long Hu, Wei Song, Huida Wang, Jiaqi Qiu, Roman Kostin, Chunguang Jing, Sergey Antipov, Peng Wang, Jia Qi, Ya Cheng, Dao Xiang, and Jie Zhang

https://journals.aps.org/prl/accepted/d407dY16M5819b51b9d98708b359b7042e3e658c9

We propose and demonstrate a Terahertz (THz) oscilloscope for recording time information of an ultrashort electron beam. By injecting a laser-driven THz pulse with circular polarization into a dielectric tube, the electron beam is swept helically such that the time information is uniformly encoded into the angular distribution that allows one to characterize both the temporal profile and timing jitter of an electron beam. The dynamic range of the measurement in such a configuration is significantly increased compared to deflection with a linearly polarized THz pulse. With this THz oscilloscope, nearly 50-fold longitudinal compression of a relativistic electron beam to about 15 fs (rms) is directly visualized with its arrival time determined with 3 fs accuracy. This technique bridges the gap between streaking of photoelectrons with optical lasers and deflection of relativistic electron beams with radio-frequency deflectors, and should have wide applications in many ultrashort electron beam based facilities.

Abstract-Spectroscopic analyses of Tm3+/Yb3+: BaGd2(MoO4)4 crystal for mid-infrared applications

Rui Wang, Peixiong Zhang, Siqi Zhu, Hao Yin, Zhen Li, Zhenqiang Chen, Yi Zheng, Guiyao Zhou, JinYu,



https://www.sciencedirect.com/science/article/pii/S1350449518302718

A Tm3+/Yb3+ co-doped BaGd2(MoO4)4 crystal was successfully grown and analyzed. The use of Tm3+ codoping for enhancement of the transition of Tm3+:3F4 → 3H6 ∼ 2 μm emissions was investigated. Compared with Tm3+ singly-doped BaGd2(MoO4)4 crystal, the Tm3+/Yb3+codoped BaGd2(MoO4)4 crystal possessed a longer fluorescence lifetime (2.467 ms), higher fluorescence emission cross section (1.174 × 10−20 cm2) corresponding to the stimulated emission of Tm3+ :3F4 → 3H6 transition. The ∼2 μm emission characteristics and energy transfer were investigated in detail. The energy transition efficiency from Tm3+:3H4 level to Yb3+:2F5/2 level, and from Yb3+:2F5/2 level to Tm3+:3H5 level were calculated to be 0.52 and 0.75, respectively. It indicates that Yb3+ can act as an effective bridge between 3H4 level and 3F4 level of Tm3+ to obtain efficient 1.9 μm emission under being pumped by a conventional 782 nm LD. Therefore, Tm3+/Yb3+ co-doped BGM crystal is a promising candidate for mid-infrared applications.

Abstract-Terahertz Streaking of Few-Femtosecond Relativistic Electron Beams

Lingrong Zhao, Zhe Wang, Chao Lu, Rui Wang, Cheng Hu, Peng Wang, Jia Qi, Tao Jiang, Shengguang Liu, Zhuoran Ma, Fengfeng Qi, Pengfei Zhu, Ya Cheng, Zhiwen Shi, Yanchao Shi, Wei Song, Xiaoxin Zhu, Jiaru Shi, Yingxin Wang, Lixin Yan, Liguo Zhu, Dao Xiang, and Jie Zhan

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.8.021061

Streaking of photoelectrons with optical lasers has been widely used for temporal characterization of attosecond extreme ultraviolet pulses. Recently, this technique has been adapted to characterize femtosecond x-ray pulses in free-electron lasers with the streaking imprinted by far-infrared and terahertz (THz) pulses. Here, we report successful implementation of THz streaking for time stamping of an ultrashort relativistic electron beam, whose energy is several orders of magnitude higher than photoelectrons. Such an ability is especially important for MeV ultrafast electron diffraction (UED) applications, where electron beams with a few femtosecond pulse width may be obtained with longitudinal compression, while the arrival time may fluctuate at a much larger timescale. Using this laser-driven THz streaking technique, the arrival time of an ultrashort electron beam with a 6-fs (rms) pulse width has been determined with 1.5-fs (rms) accuracy. Furthermore, we have proposed and demonstrated a noninvasive method for correction of the timing jitter with femtosecond accuracy through measurement of the compressed beam energy, which may allow one to advance UED towards a sub-10-fs frontier, far beyond the approximate 100-fs (rms) jitter.

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Abstract-Terahertz streaking of few-femtosecond relativistic electron beams

Lingrong Zhao, Zhe Wang, Chao Lu, Rui Wang, Cheng Hu, Peng Wang, Jia Qi, Tao Jiang, Shengguang Liu, Zhuoran Ma, Fengfeng Qi, Pengfei Zhu, Ya Cheng, Zhiwen Shi, Yanchao Shi, Wei Song, Xiaoxin Zhu, Jiaru Shi, Yingxin Wang, Lixin Yan, Liguo Zhu, Dao Xiang,  Jie Zhang,

https://journals.aps.org/prx/accepted/d8075K71A261f001129c7ce70c632d2221b6fd030

Streaking of photoelectrons with optical lasers has been widely used for temporal characterization of attosecond extreme ultraviolet pulses. Recently, this technique has been adapted to characterize femtosecond x-ray pulses in free-electron lasers with the streaking imprinted by far-infrared and Terahertz (THz) pulses. Here, we report successful implementation of THz streaking for time-stamping of an ultrashort relativistic electron beam of which the energy is several orders of magnitude higher than photoelectrons. Such ability is especially important for MeV ultrafast electron diffraction (UED) applications where electron beams with a few femtosecond pulse width may be obtained with longitudinal compression while the arrival time may fluctuate at a much larger time scale. Using this laser-driven THz streaking technique, the arrival time of an ultrashort electron beam with 6 fs (rms) pulse width has been determined with 1.5 fs (rms) accuracy. Furthermore, we have proposed and demonstrated a non-invasive method for correction of the timing jitter with femtosecond accuracy through measurement of the compressed beam energy, which may allow one to advance UED towards sub-10 fs frontier far beyond the $\sim$100 fs (rms) jitter.

Abstract-Dual-wavelength narrow-linewidth linearly polarized seed source and stimulated Brillouin scattering suppression in its high-power fiber amplification

Yaqian Ding, Yuan Liu, Yunfeng Qi, Lei Zhang, Baoling Guo, Rui Wang, Jun Zhou, and Guanghui Chen

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-54-22-6616#Abstract

In this paper, we demonstrate a dual-wavelength narrow-linewidth linearly polarized all-fiber amplifier emitting 1035 and 1030 nm wavelengths with a high power of 80.0 W. The seed source features two sets of fiber Bragg gratings fabricated on polarization maintaining fibers and a ytterbium-doped fiber as the gain medium. Two wavelengths propagate in one overlapping cavity and the power ratio can be tuned by a coiling fiber setup. A master oscillator power amplifier system consisting of a two-stage amplifier is employed. Longitudinally varied strains are applied on the gain fiber to suppress the back-scattered Stokes light in the main amplifier stage. With an appropriate seed power ratio, we are able to generate amplification power to 80.0 W comprised of 1035 and 1030 nm light while achieving an increase of at least six times that of the stimulated Brillouin scattering threshold. Since both frequencies are propagating in one cavity and amplified in one gain medium, the 1035 and 1030 nm lasers have good temporal and spatial overlapping characteristics. This high-power MHz-level linearly polarized structure affords a compact, novel, and high-efficiency approach to different frequency generation of mid-infrared or terahertz emission.

© 2015 Optical Society of America

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