检索结果-内蒙古大学图书馆

Analysis of light wave diffraction and amplification by reflection grating operating in the second-order Bragg regime. 2. Reflectivity and spectral characteristics of a grating

引用

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 2012年第5期29卷 944-949页

作者： Fitio, Volodymyr M. Smirnova, Tatiana N. Natl Acad Sci Ukraine Inst Phys UA-03680 Kiev Ukraine Lviv Polytech Natl Univ Lvov Ukraine

Reflectivity and spectral properties of a thick reflection grating are discussed for the second-order Bragg diffraction regime. Analytical expressions for the reflection and gain coefficients are obtained with the help of the developed theory. A procedure is proposed for determining the wavelength of laser oscillations generated in an optically active grating. The influence of the second harmonic of dielectric permittivity spatial modulation on reflection and spectral characteristics of a grating was also analyzed. Comparison of the approximate results obtained by the proposed approach and by the numerical solution is carried out, and their excellent agreement is demonstrated. (C) 2012 Optical Society of America

关键词： Diffraction theory Volume gratings Lasers distributed-feedback

来源：评论

学校读者我要写书评

暂无评论

Multimode lasing dynamics of photonic band-gap microlasers

引用

LASER PHYSICS 2004年第5期14卷 720-726页

作者： Smirnov, AG NASB Stepanov Inst Phys Minsk 220072 BELARUS

Finite-difference time-domain simulation of lasing, action in a one-dimensional band-gap material is carried out using Maxwell-Bloch equations for a four-level model of an active medium. A comparative analysis of various lasing schemes utilizing band-gap materials is presented. A new type of coupled-cavity photonic band-gap microlaser is proposed to provide low-threshold lasing at multiple wavelengths.

关键词： distributed-feedback CRYSTALS LASER ENHANCEMENT MODES GAIN

来源：评论

学校读者我要写书评

暂无评论

Normalized pulsed energy thresholding in a nonlinear optical loop mirror

引用

APPLIED OPTICS 2015年第11期54卷 3218-3224页

作者： Nahmias, M. A. Shastri, B. J. Tait, A. N. Eder, M. Rafidi, Nicole Tian, Yue Prucnal, P. R. Princeton Univ Dept Elect Engn Lightwave Commun Lab Princeton NJ 08544 USA

We demonstrate for the first time, to the best of our knowledge, that a Sagnac interferometer can threshold the energies of pulses. Pulses below a given threshold T are suppressed, while those above this threshold are normalized. The device contains an in-loop tunable isolator and 10.4 m of a highly doped silica fiber. We derive an analytical model of the nonlinear optical loop mirror's pulse energy transfer function and show that its energy transfer function approximates a step function for very high phase shifts (>pi). We reveal some limitations of this approach, showing that a step-function transfer function necessarily results in pulse distortion in fast, nonresonant all-optical devices. (C) 2015 Optical Society of America

关键词： Fiber optics sensors Fibers polarization-maintaining Fiber Bragg gratings Lasers distributed-feedback

来源：评论

学校读者我要写书评

暂无评论

Cavity ringdown spectroscopic detection of nitric oxide with a continuous-wave quantum-cascade laser

引用

APPLIED OPTICS 2001年第30期40卷 5522-5529页

作者： Kosterev, AA Malinovsky, AL Tittel, FK Gmachl, C Capasso, F Sivco, DL Baillargeon, JN Hutchinson, AL Cho, AY Rice Univ Rice Quantum Inst Houston TX 77251 USA Bell Labs Lucent Technol Murray Hill NJ 07974 USA

A spectroscopic gas sensor for nitric oxide (NO) detection based on a cavity ringdown technique was designed and evaluated. A cw quantum-cascade distributed-feedback laser operating at 5.2 mum was used as a tunable single-frequency light source. Both laser-frequency tuning and abrupt interruptions of the laser radiation were performed through manipulation of the laser current. A single ringdown event sensitivity to absorption of 2.2 x 10(-8) cm(-1) was achieved. Measurements of parts per billion (ppb) NO concentrations in N-2 with a 0.7-ppb standard error for a data collection time of 8 s have been performed. Future improvements are discussed that would allow quantification of NO in human breath. (C) 2001 Optical Society of America.

关键词： .ppb Spectroscopic detection losses CRDs quantum-cascade mirror optical cavity distributed-feedback NO detection Cavity ringdown spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Manipulation of light propagation in photonic crystal

引用

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 2015年第10期32卷 2122-2128页

作者： Yang, Zhiyuan Joshi, Amitabh Kasumova, Rena Rostovtsev, Yuri Univ N Texas Dept Phys Denton TX 76203 USA Univ N Texas Ctr Nonlinear Sci Denton TX 76203 USA Adelphi Univ Dept Phys Garden City NY 11530 USA Baku State Univ Dept Phys AZ-1148 Baku Azerbaijan

The propagation of probe electromagnetic waves has been investigated in a heterostructure formed by layers having linear and nonlinear optical properties. The appearance of a forbidden bandgap for the probe electromagnetic field induced by another control electromagnetic field has been shown that leads to the trapping of the probe pulse inside the structure. Switching off the control field leads to resuming the propagation of the probe pulse. Implementation of nonlinear layer has been suggested. (C) 2015 Optical Society of America

关键词： Fibers polarization-maintaining Fiber Bragg gratings Lasers distributed-feedback

来源：评论

学校读者我要写书评

暂无评论

Simple parametric model for intensity calibration of Cassini composite infrared spectrometer data

引用

APPLIED OPTICS 2016年第17期55卷 4699-4705页

作者： Brasunas, J. Mamoutkine, A. Gorius, N. NASA Goddard Space Flight Ctr Code 693 Greenbelt MD 20771 USA Adnet Syst 8800 Greenbelt RdCode 693 Greenbelt MD 20771 USA Catholic Univ 8800 Greenbelt RdCode 693 Greenbelt MD 20771 USA

Accurate intensity calibration of a linear Fourier-transform spectrometer typically requires the unknown science target and the two calibration targets to be acquired under identical conditions. We present a simple model suitable for vector calibration that enables accurate calibration via adjustments of measured spectral amplitudes and phases when these three targets are recorded at different detector or optics temperatures. Our model makes calibration more accurate both by minimizing biases due to changing instrument temperatures that are always present at some level and by decreasing estimate variance through incorporating larger averages of science and calibration interferogram scans.

关键词： Spectrometers and spectroscopic instrumentation Space instrumentation Lasers distributed-feedback Spectroscopy Fourier transforms

来源：评论

学校读者我要写书评

暂无评论

Numerical analysis of broadband fiber optical parametric amplifiers pumped by two chirped pulses

引用

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 2016年第9期33卷 1800-1807页

作者： Bigourd, Damien Dutin, Coralie Fourcade Vanvincq, Olivier Hugonnot, Emmanuel Univ Bourgogne Franche Comte Inst FEMTO ST Dept Opt UMR 6174CNRS F-25030 Besancon France Univ Lille CNRS Lab PhLAM Phys Lasers Atomes & Mol UMR 8523 F-59655 Villeneuve Dascq France Commissariat Energie Atom & Energies Alternat Ctr Etud Sci & Tech Aquitaine F-33116 Le Barp France

An optical parametric amplifier pumped by two chirped pump pulses has been analytically and numerically investigated to predict the spectral gain bandwidth and its temporal distribution. We highlight that the properties of the amplifier depend strongly on the relative chirp values and a uniform spectrotemporal gain can be obtained when the two chirps have opposite signs. A chirped signal pulse owing a very broad bandwidth has also been injected and we demonstrate the amplification of ultrashort pulse with this type of amplifier. (C) 2016 Optical Society of America

关键词： Nonlinear optics fibers Lasers distributed-feedback Nonlinear optics four-wave mixing Nonlinear optics parametric processes

来源：评论

学校读者我要写书评

暂无评论

Terahertz light-emitting graphene-channel transistor toward single-mode lasing

引用

NANOPHOTONICS 2018年第4期7卷 741-752页

作者： Yadav, Deepika Tamamushi, Gen Watanabe, Takayuki Mitsushio, Junki Tobah, Youssef Sugawara, Kenta Dubinov, Alexander A. Satou, Akira Ryzhii, Maxim Ryzhii, Victor Otsuji, Taiichi Tohoku Univ Res Inst Elect Commun Sendai Miyagi 9808577 Japan Univ Texas Austin Dept Elect & Comp Engn Austin TX 78712 USA Lobachevsky State Univ Nizhny Novgorod Russian Acad Sci Inst Phys Microstruct Nizhnii Novgorod 603950 Russia Univ Aizu Dept Comp Sci & Engn Aizu Wakamatsu Fukushima 9658580 Japan Tohoku Univ Res Inst Elect Commun Sendai Miyagi 9808577 Japan Bauman Moscow State Tech Univ Ctr Photon & Infrared Engn Moscow 105005 Russia

A distributed feedback dual-gate graphene-channel field-effect transistor (DFB-DG-GFET) was fabricated as a current-injection terahertz (THz) light-emitting laser transistor. We observed a broadband emission in a 1-7.6-THz range with a maximum radiation power of similar to 10 mu W as well as a single-mode emission at 5.2 THz with a radiation power of similar to 0.1 mu W both at 100 K when the carrier injection stays between the lower cutoff and upper cutoff threshold levels. The device also exhibited peculiar nonlinear threshold-like behavior with respect to the current-injection level. The LED-like broadband emission is interpreted as an amplified spontaneous THz emission being transcended to a single-mode lasing. Design constraints on waveguide structures for better THz photon field confinement with higher gain overlapping as well as DFB cavity structures with higher Q factors are also addressed towards intense, single-mode continuous wave THz lasing at room temperature.

关键词： graphene lasers far infrared or terahertz pumping current injection distributed-feedback optoelectronics

来源：评论

学校读者我要写书评

暂无评论

Beam combining of quantum cascade laser arrays

引用

OPTICS EXPRESS 2009年第18期17卷 16216-16224页

作者： Lee, Benjamin G. Kansky, Jan Goyal, Anish K. Pfluegl, Christian Diehl, Laurent Belkin, Mikhail A. Sanchez, Antonio Capasso, Federico Harvard Univ Sch Engn & Appl Sci Cambridge MA 02138 USA MIT Lincoln Lab Lexington MA 02173 USA

Wavelength beam combining was used to co-propagate beams from 28 elements in an array of distributed-feedback quantum cascade lasers (DFB-QCLs). The beam-quality product of the array, defined as the product of near-field spot size and far-field divergence for the entire array, was improved by a factor of 21 by using wavelength beam combining. To demonstrate the applicability of wavelength beam combined DFB-QCL arrays for remote sensing, we obtained the absorption spectrum of isopropanol at a distance of 6 m from the laser array. (C) 2009 Optical Society of America

关键词： .laser beam Beam combining Quantum cascade lasers laser arrays distributed-feedback wavelength beam co-propagate DFB-QCLs beam-quality product

来源：评论

学校读者我要写书评

暂无评论

A microscope using Zernike's phase contrast method and a hard x-ray Gabor hologram

引用

JOURNAL OF THE EUROPEAN OPTICAL SOCIETY-RAPID PUBLICATIONS 2016年第1期12卷 1-7页

作者： Matsuda, Kiyofumi Aguilar, Juan C. Misawa, Masaki Yasumoto, Masato Rehman, Shakil Suzuki, Yoshio Takeuchi, Akihisa Niskanen, Ilpo Natl Inst Adv Ind Sci & Technol Theranost Device Res Grp Hlth Res Inst 1-2-1 Namiki Tsukuba Ibaraki 3058564 Japan Grad Sch Creat New Photon Ind Nishi Ku 1955-1 Kurematsu Hamamatsu Shizuoka 4311202 Japan Inst Nacl Astrofis Opt & Electr Luis Enrique Erro 1 Tonantzintla Puebla Mexico Natl Inst Adv Ind Sci & Technol NMIJ Res Inst Measurement & Analyt Instrumentat Tsukuba Ibaraki 3058568 Japan Japan Synchrotron Radiat Res Inst SPring 8 Sayo Hyogo 6795198 Japan Singapore Alliance Res & Technol SMART Ctr 1 CREATE Way 09-03CREATE Tower Singapore 138602 Singapore Univ Oulu Fac Technol POB 73009014 Oulu Finland

Background: In hard X-ray phase imaging using interferometry, the spatial resolution is limited by the pixel size of digital sensors, inhibiting its use in magnifying observation of a sample. Methods: To solve this problem, we describe a digital phase contrast microscope that uses Zernike's phase contrast method with a hard X-ray Gabor holography associated with numerical processing and spatial frequency domain filtering techniques. The hologram is reconstructed by a collimated beam in a computer. The hologram intensity distributions itself become the reconstructed wavefronts. For this transformation, the Rayleigh-Sommerfeld diffraction formula is used. Results: The hard X-ray wavelength 0.1259 nm (an energy of 9.85 keV) was employed at the SPring-8 facility. We succeeded in obtaining high-resolution images by a CCD sensor with a pixel size of 3.14 mu m, even while bound by the need to satisfy the sampling theorem and by the CCD pixel size. The test samples used here were polystyrene beads of 8 mu m, and human HeLa cells. Conclusions: We thus proved that the resolution 0.951 mu m smaller than the pixel size of CCD (3.14 mu m) was achieved by the proposed reconstruction techniques and coherent image processing in the computer, suggesting even higher resolutions by adopting greater numerical apertures.

关键词： X-ray microscopy distributed-feedback Digital holography X-ray imaging Interference microscopy X-ray interferometry

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：