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951.
B. Q. Yao F. Chen C. T. Wu Q. Wang G. Li C. H. Zhang Y. Z. Wang Y. L. Ju 《Laser Physics》2011,21(3):468-471
In this paper, we presented experimental results concerning on the laser characteristics of two microchip lasers emitting
in the 2 μm range, Tm:Ho:YVO4 microchip laser and Tm:Ho:GdVO4 microchip laser. At a heat sink temperature of 283 K, the maximum output power of Tm:Ho:YVO4 laser and Tm:Ho:GdVO4 laser is 47 and 34 mW under absorbed pump power of 912 mW, respectively. High efficiency can be achieved for both lasers
at room temperature. Nevertheless, compared with Tm:Ho:GdVO4 laser, Tm:Ho:YVO4 laser can operate on single frequency with high power easily. At the heat sink temperature of 288 K, as much as 16.5 mW of
2052.3 nm single-longitudinal-mode (SLM) laser was achieved for Tm:Ho:YVO4 laser. Under the same condition, only 8 mW of 2048.5 nm SLM laser was achieved for Tm:Ho:GdVO4 laser. 相似文献
952.
B. Q. Yao F. Chen C. T. Wu Q. Wang G. Li C. H. Zhang Y. Z. Wang Y. L. Ju 《Laser Physics》2011,21(4):663-666
Room temperature Tm, Ho:YVO4 microchip laser operated around 2 μm was demonstrated for the first time to our knowledge. At a heat sink temperature of
283 K, a maximum output power of 47 mW was obtained by using a 0.25 mm length crystal at an absorbed pump power of 912 mW,
corresponding to a slope efficiency of 9.1%. Increasing the temperature to 288 K, as much as 16.5 mW 2052.3 nm single-longitudinal-mode
laser was achieved. The M
2 factor was measured to be 1.4. 相似文献
953.
A novel artificial anion receptor based on phenylhydrazone structure was designed, synthesized and characterized. The binding behavior of the receptor to various anions was investigated by UV-vis fluorescence analyses. In addition, 1H NMR experiments were carried out to explore the nature of interaction between receptor 1 and acetate. The processes of sensing can literally be seen through the ‘naked-eye’ for the sharp color changes from yellow to purple. 相似文献
954.
An information hiding method based on the optical interference principle is proposed. In this method, a secret image can be obtained by two light beams' interference. One of the beams is modulated by our assigned host image; and the other is modulated by a noise-like complex distribution, which is regard as the encrypted image. The transmission of the encrypted image can be implemented by hiding it in the host image to prevent the communication from being perceived by unauthorized person. In addition, this method can also realize simultaneous encryption and hiding for two images. A series of numerical simulation results are presented to verify the feasibility of our proposed method. 相似文献
955.
We report a new type of black silicon: flexible black silicon. A silicon-on-insulator (SOI) wafer is irradiated by automatically scanning a femtosecond laser and then split by etching out the SOI silica middle layer. Large-area, uniform micro spikes on the surface of a very thin flexible silicon layer are obtained. The black silicon shows good flexibility and optical properties. The absorption spectrum of the flexible black silicon is as high as 97% in the visible and insensitive to the change of the incident angle of the light, which makes it a potential good candidate as an absorber for the solar-thermo generator. 相似文献
956.
Chunting Wu Youlun Ju Qiang Wang Zhenguo Wang Baoquan Yao Yuezhu Wang 《Optics Communications》2011,284(4):994-998
The solid-state, tunable, narrowband, high pulse energy and high reliability lasers are attractive source for LIDAR system. In this paper, we demonstrated a diode pumped injection-seeded 2 μm Tm:YAG laser. By inserting two F-P etalons into the laser cavity, linear-polarized single-frequency seed-laser was achieved at a wavelength of 2013 nm, with a maximum output power of 60 mW. Long-term and short-term frequency stability for the seed-laser were 1.27 × 10− 7 and 97 Hz/μs, respectively. High power Q-switched laser was operated using a bowtie cavity, the bidirectional output of which was favorable for the injection-seeded. After injecting the seed-laser to the power-laser, single-frequency, nearly transform-limited pulsed 2 μm laser was obtained. As much as 2.0 mJ output energy was achieved at an operating repetition rate of 15 Hz, with a pulse width of 356.2 ns. 相似文献
957.
We have simulated the coupling loss of three types of Inverse Taper and taper-lensed fiber using three dimensional (3D) semi-vectorial beam propagation methods (BPM) respectively. Our results showed that the performances of exponential inverse taper and quadratic inverse taper were better than the commonly used linear inverse taper. Especially, for TM mode the improvement in the reduction of devices size is 53% and 136% for exponential and quadratic inverse taper compared with the linear inverse taper. 相似文献
958.
He RH Fujita M Enoki M Hashimoto M Iikubo S Mo SK Yao H Adachi T Koike Y Hussain Z Shen ZX Yamada K 《Physical review letters》2011,107(12):127002
We demonstrated experimentally a direct way to probe a hidden propensity to the formation of a spin-density wave in a nonmagnetic metal with strong Fermi surface nesting. Substituting Fe for a tiny amount of Cu (1%) induced an incommensurate magnetic order below 20 K in heavily overdoped La(2-x)Sr(x)CuO(4). Elastic neutron scattering suggested that this order cannot be ascribed to the localized spins on Cu or doped Fe. Angle-resolved photoemission revealed a strong Fermi surface nesting inherent in the pristine La(2-x)Sr(x)CuO(4) that likely drives this order. Our finding presents the first example of the long-sought "itinerant-spin extreme" of cuprates, where the spins of itinerant doped holes define the magnetic ordering ground state; it complements the current picture of cuprate spin physics that highlights the predominant role of localized spins at lower dopings. 相似文献
959.
Haifeng Yao Yueping Niu Yandong Peng Shangqing Gong 《Optics Communications》2011,284(16-17):4059-4063
We investigate the nonlinear propagation of few-cycle rectangular laser pulses on resonant intersubband transitions in semiconductor quantum wells using an iterative predictor–corrector finite-difference time-domain method. An initial 2π rectangular pulse will split into Sommerfeld–Brillouin precursors and a self-induced transparency soliton during the course of propagation. The duration of generated soliton depends on the carrier-envelope phase of the incident pulse. In our case, not only the near-resonant frequency components but also the low frequency components could contribute to the generation of the soliton pulse when the condition of multi-photon resonance is satisfied. The phase-sensitive property of the solitons results from the phase-dependent distribution of high and low frequency sidebands of few-cycle rectangular pulses. 相似文献
960.
We investigate the spin-orbit opened energy gap and the band topology in recently synthesized silicene as well as two-dimensional low-buckled honeycomb structures of germanium using first-principles calculations. We demonstrate that silicene with topologically nontrivial electronic structures can realize the quantum spin Hall effect (QSHE) by exploiting adiabatic continuity and the direct calculation of the Z(2) topological invariant. We predict that the QSHE can be observed in an experimentally accessible low temperature regime in silicene with the spin-orbit band gap of 1.55 meV, much higher than that of graphene. Furthermore, we find that the gap will increase to 2.9 meV under certain pressure strain. Finally, we also study germanium with a similar low-buckled stable structure, and predict that spin-orbit coupling opens a band gap of 23.9 meV, much higher than the liquid nitrogen temperature. 相似文献