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Chinese Optics Letters 第15卷 第7期

Author Affiliations
Abstract
1 State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou 310027, China
2 College of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China
3 Key Laboratory of RF Circuit & System (Hangzhou Dianzi University), Ministry of Education, Hangzhou 310018,China
Multi-photon parametric magnetic resonance in a miniature vapor cell is demonstrated. Much more multi-photon magnetic resonance can be observed when the radio frequency field becomes stronger. The linewidth of the n photons magnetic resonance equals that of the first-order resonance divided by n, which means that the uncertainty of the magnetic sublevel is reduced by the factor n. The signal-to-noise ratio can be improved when the low-frequency multi-photon resonance takes place, which finds a possible application in precision magnetic field measurement.
020.7490 Zeeman effect 270.4180 Multiphoton processes 
Chinese Optics Letters
2017, 15(7): 070201
Author Affiliations
Abstract
1 The MOE Key Laboratory of Weak-Light Nonlinear Photonics, and TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China
2 Faculty of Mathematics and Physics, University of Ljubljana and Department of Complex Matter, J. Stefan Institute, Ljubljana SI1000, Slovenia
3 Faculty of Physics, Vienna University, Wien A-1090, Austria
4 Synergetic Innovation Center of Chemical Science and Engineering, Tianjin 300071, China
We develop a new method for smooth and continuous space-variant alignment of the liquid crystal medium in micro-patterned structures, which is based on a radial micro-structured pattern of polymeric ribbons exhibiting out-of-plane orientation with respect to the ITO-coated glass plates. Thanks to the broad range of electrical tunability of the optical retardation for the micro-patterned liquid crystal structures, transformation of the fundamental Gaussian beam into different types of specific beams, including generalized cylindrical vector beams, vortex beams, and vectorial vortex beams, is efficiently demonstrated.
050.4865 Optical vortices 230.3720 Liquid-crystal devices 220.0220 Optical design and fabrication 
Chinese Optics Letters
2017, 15(7): 070501
Author Affiliations
Abstract
Laboratory of Specialty Fiber Optics and Optical Access Networks, School of Communication and Information Engineering, Shanghai University, Shanghai 200072, China
A simple capillary-based extrinsic Fabry–Perot structure is presented and fabricated, using the manual welding method with the strain sensing characteristics investigated in detail. Strain sensitivities of 4.2, 2.8, and 2.4 pm/με are obtained experimentally with the interferometer length around 50 μm and the inner diameter of 75, 50, and 25 μm, respectively. The underlying physics of the strain sensitivity of this device is negatively correlated with the interferometer length and positively correlated with the capillary inner diameter, which provides two simple parameters to tailor the strain sensitivity.
060.2370 Fiber optics sensors 
Chinese Optics Letters
2017, 15(7): 070601
Author Affiliations
Abstract
1 Bialystok University of Technology, Bialystok 15-351, Poland
2 AGH University of Science and Technology, Krakow 30-059, Poland
Lanthanide-doped polymers are very attractive, since they can be used for luminescent optical fiber fabrications. This Letter presents the terbium-ions-doped poly(methyl methacrylate) fiber fabrication and spectroscopic characterization. The measured excited state (D45) lifetime of 0.741 ms confirms that a used organometallic can be used to obtain an intense luminescence in a polymeric fiber. The luminescence spectrum shape modification versus the fiber length is also investigated.
060.2280 Fiber design and fabrication 160.4890 Organic materials 160.2540 Fluorescent and luminescent materials 
Chinese Optics Letters
2017, 15(7): 070602
Author Affiliations
Abstract
1 Information and Navigation College, Air Force Engineering University, Xi’an 710077, China
2 Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
An approach for photonic generation of a frequency-octupled phase-coded signal based on carrier-suppressed high-order double sideband modulation is proposed and experimentally demonstrated. The key component of the scheme is an integrated dual-polarization quadrature phase shift keying modulator, which is used to achieve the carrier-suppressed high-order double sideband modulation. At the output of the modulator, two fourth-order optical sidebands are generated with the optical carrier suppressed. After that, a Sagnac loop incorporating a fiber Bragg grating and a phase modulator is employed to separate the two optical sidebands and phase modulate one sideband with a binary coding signal. The approach features large carrier frequency tuning range for the generated phase-coded signal from several megahertz to beyond the W-band. A proof-of-concept experiment is carried out. The 2 Gbit/s phase-coded signals with frequencies of 16.48, 21.92, and 29.76 GHz are generated.
060.2330 Fiber optics communications 060.5625 Radio frequency photonics 
Chinese Optics Letters
2017, 15(7): 070603
Author Affiliations
Abstract
1 Institute of Information Science, Beijing Jiaotong University, Beijing 100044, China
2 Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou, 510632, China
3 Institute of Optical Information, Beijing Jiaotong University, Beijing 100044, China
We present a theoretical analysis and an experimental study of the impacts of external optical feedback on dual-frequency fiber lasers. The external optical feedback can effectively suppress the phase noise of the beat notes of dual-frequency fiber lasers, provided some requirements are satisfied. The polarization of the optical feedback is important for the fiber laser’s stability, and it can also tune the beat note frequency. A side effect of external optical feedback, as demonstrated in the experiments, is lowering the sensitivity of the dual-frequency fiber laser-based sensors, although such degradation is not obvious.
060.2370 Fiber optics sensors 140.3425 Laser stabilization 
Chinese Optics Letters
2017, 15(7): 070604
Author Affiliations
Abstract
1 Key Laboratory of Optoelectronics Information Technology, Institute of Optical Fiber Sensing of Tianjin University, MEC, Tianjin 300072, China
2 School of Computer and Information Engineering, Tianjin Chengjian University, Tianjin 300384, China
A new wavelength division multiplexing method for fiber Bragg grating (FBG) sensors based on spectrum profile identification is proposed. In this method, FBGs and tilted FBG (TFBG) sensors are cascaded in a single fiber in one sensing channel. The different spectrum profiles enable the cross-correlation method to demodulate the wavelength. Therefore, the different types of sensors can occupy the same central wavelength band. Using this method, the multiplexing capacity is optimized. Experiment results demonstrate the feasibility of this method and it is useful for applications where large numbers of FBGs are needed.
060.0060 Fiber optics and optical communications 060.3735 Fiber Bragg gratings 060.2370 Fiber optics sensors 
Chinese Optics Letters
2017, 15(7): 070605
Author Affiliations
Abstract
School of Physical Sciences, National Institute of Science Education and Research, HBNI Bhubaneswar, Jatni 752050, India
We propose a broadband fiber optic parametric amplifier (FOPA) based on a near-zero ultra-flat dispersion profile with a single zero-dispersion wavelength (ZDW) by using a selective liquid infiltration technique. The amplifier gain and bandwidth is investigated for a variety of fiber lengths, pump power, and operating wavelengths. It is observed that sufficient peak gains and broader bandwidths can be achieved with a small negative anomalous dispersion (β20) and a positive value of the 4th-order dispersion parameter (+ β4) around the pump. We can optimize an FOPA with a bandwidth of more than 220 nm around the communications wavelength.
060.4005 Microstructured fibers 060.5295 Photonic crystal fibers 190.4970 Parametric oscillators and amplifiers 
Chinese Optics Letters
2017, 15(7): 070606
Author Affiliations
Abstract
School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150001, China
A laser interferometry technique is developed to detect water surface capillary waves caused by an impinging acoustic pressure field. The frequency and amplitude of the water surface capillary waves can be estimated from the local signal data at some special points of the phase modulated interference signal, which is called the turning points. Demodulation principles are proposed to explain this method. Experiments are conducted under conditions of different intensity and different frequency driving acoustic signals. The results show the local signal data analysis can effectively estimate the amplitude and frequency of water surface capillary waves.
120.3180 Interferometry 120.7280 Vibration analysis 
Chinese Optics Letters
2017, 15(7): 071201
Author Affiliations
Abstract
1 Department of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, South Korea
2 Innovations for High Performance Microelectronics (IHP), Frankfurt (Oder) 15236, Germany
We experimentally observe that Si micro-ring modulator (MRM) modulation characteristics are strongly influenced by the modulation data rate and the data pattern and determine this influence is due to the temperature increase caused by dynamic power dissipation within the Si MRM device. We also quantitatively determine the amount of Si MRM resonance wavelength shift due to different modulation data rates, data patterns, and modulation voltages. Our results should be of great help for achieving reliable and optimal modulation characteristics for Si MRMs.
130.4110 Modulators 230.4110 Modulators 230.5750 Resonators 
Chinese Optics Letters
2017, 15(7): 071301
Author Affiliations
Abstract
Institute of Laser Engineering, Beijing University of Technology, Beijing 100124, China
We demonstrate a continuous-wave (CW) dual-wavelength Nd:YVO4 laser working at 1064 and 1066 nm simultaneously. The method of Nd:YVO4 crystal angle tuning is used to balance the ratio of the stimulated emission cross sections of the two wavelengths, leading to the realization of a simultaneous dual-wavelength operation from only one laser. The experimental results show that at a 2.85 W pump power, the maximum output powers at wavelengths of 1064 and 1066 nm are 0.55 and 0.54 W, respectively. The linear resonate cavity is as short as 10 mm, which gives the laser the advantages of a miniature configuration and low threshold. Such a dual-wavelength laser can be very attractive for the development of compact THz sources based on difference frequency generation.
140.3580 Lasers, solid-state 
Chinese Optics Letters
2017, 15(7): 071401
Zhijun Yuan 1,2Haibo Zhang 1,2Ren Ye 1,2Jun Zhou 1,2,*[ ... ]Qihong Lou 1,2
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Shanghai Key Laboratory of All Solid-state Laser and Applied Techniques, Shanghai 201800, China
Accurate and precise wavelength controlling of narrowband excimer lasers is essential for the lithography of an integrated circuit. High-precision wavelength tuning and calibration of a line-narrowed ArF laser are presented in this work. The laser spectrum is narrowed to a sub-picometer with a line narrowing system. Absolute wavelength calibration of the line-narrowed laser is performed based on the optogalvanic (OG) effect using iron hollow cathode discharge (HCD). An sccuracy of better than 0.1 pm for wavelength tuning and calibration is achieved with our homemade wavemeter.
140.2180 Excimer lasers 150.1488 Calibration 300.6440 Spectroscopy, optogalvanic 300.3700 Linewidth 
Chinese Optics Letters
2017, 15(7): 071402
Author Affiliations
Abstract
The State Key Laboratory of High Performance Complex Manufacturing, College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China
A fused silica glass micro-channel can be formed by chemical etching after femtosecond laser irradiation, and the successful etching probability is only 48%. In order to improve the micro-channel fabrication success probability, the method of processing a high-temperature lattice by a femtosecond laser pulse train is provided. With the same pulse energy and scanning speed, the success probability can be increased to 98% by optimizing pulse delay. The enhancement is mainly caused by the nanostructure, which changes from a periodic slabs structure to some intensive and loose pore structures. In this Letter, the optimum pulse energy distribution ratio to the etching is also investigated.
140.0140 Lasers and laser optics 230.7380 Waveguides, channeled 
Chinese Optics Letters
2017, 15(7): 071403
Author Affiliations
Abstract
1 State Key laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 Suzhou Everbright Photonics Co., Ltd, Suzhou 215000, China
Far-field blooming, a serious far-field dependence on driving current, affects the stability of beam quality and applications of broad-area (BA) diode lasers. In this Letter, the lateral ridge waveguide (LRW) is introduced to BA lasers by a simple and cost-effective approach to control the far-field stability and beam divergence. The influences of LRW length on output power, near- and far-field, are investigated and it is found that the optimized LRW length is able to improve both the far-field blooming and output power. The mechanism behind this is analyzed and a 0.13°/A dependence of lateral divergence angle on the injection current is achieved.
140.2020 Diode lasers 
Chinese Optics Letters
2017, 15(7): 071404
Author Affiliations
Abstract
1 Faculty of Electrical Engineering, University Teknologi Mara, Shah Alam 40450, Malaysia
2 Department of Electrical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
3 Faculty of Electrical Engineering, University Teknologi Mara (Terengganu), Dungun 23000, Malaysia
4 Photonics Research Center, University of Malaya, Kuala Lumpur 50603, Malaysia
We demonstrate the generation of mode-locked pulses in an erbium-doped fiber laser (EDFL) by using a new manganese-doped cadmium selenide quantum-dots-based saturable absorber. The laser produces a soliton pulse train operating at 1561.1 nm with a repetition rate of 1 MHz, as the pump power is varied from 113 to 250 mW. At the maximum pump power, we obtain the pulse duration of 459 ns with a signal-to-noise ratio of 50 dB.
140.4050 Mode-locked lasers 140.3500 Lasers, erbium 
Chinese Optics Letters
2017, 15(7): 071405
Author Affiliations
Abstract
1 State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
3 School of Physical Science and Technology, Shanghai Tech University, Shanghai 200031, China
4 University of Chinese Academy of Sciences, Beijing 100049, China
The laser performance of a new Yb:germanophosphate (Yb:GP) glass is investigated. A maximum output power of 826 mW at 1063 nm is achieved with direct diode pumping at 976 nm. The wavelength is tuned from 1034.47 to 1070.83 nm, corresponding to a tuning range of 36.36 nm. Thermal lens effects are investigated to optimize the optical cavity.
140.3580 Lasers, solid-state 140.3615 Lasers, ytterbium 140.3600 Lasers, tunable 
Chinese Optics Letters
2017, 15(7): 071406
Author Affiliations
Abstract
1 Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Research Center of Space Laser Information Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Department of Space and Command, Academy of Equipment, Beijing 101416, China
3 University of Chinese Academy of Sciences, Beijing 100049, China
4 Huazhong University of Science and Technology, Wuhan 430073, China
We report a 307 W 1018 nm Yb-doped fiber laser pumped by a single 976 nm laser diode. The cavity slope efficiency is up to 75.9% and the amplified spontaneous emission is suppressed by 54 dB. The beam quality of the output laser has an M2 factor of 1.17. Effective thermal management is considered to ensure the stable operation of our system. The power stability at the maximum output power level is measured during a period of 0.5 h and the power fluctuation is less than 0.8%. This architecture can be an effective high brightness pump source of core-pumping high-power fiber amplifiers.
140.3510 Lasers, fiber 140.3615 Lasers, ytterbium 140.6810 Thermal effects 
Chinese Optics Letters
2017, 15(7): 071407
Author Affiliations
Abstract
College of Applied Sciences, Beijing University of Technology, Beijing, 100124, PR China
We experimentally demonstrate a cascaded Raman scattering continuum, utilizing a compact mode-locked Yb-doped fiber laser based on a nonlinear polarization rotation technique in the all normal dispersion regime. There is no physical filter or polarization controller in the oscillator, and a different mode-locked operation is achieved, corresponding to the extra fiber location in the oscillator. The broadband spectrum generation owes to the enhanced stimulated Raman scattering progress. The maximum output average power and peak power are 14.75 nJ and 18.0 W, and the short coherence light is suited for optical coherence tomography.
140.3510 Lasers, fiber 140.3550 Lasers, Raman 140.4050 Mode-locked lasers 
Chinese Optics Letters
2017, 15(7): 071408
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
We theoretically investigate the attosecond pulse generation in an orthogonal multicycle midinfrared two-color laser field. It is demonstrated that multiple continuum-like humps, which consist of about twenty orders of harmonics and an intensity of about one order higher than the adjacent normal harmonics, are generated when longer wavelength driving fields are used. By filtering these humps, intense isolated attosecond pulses (IAPs) are directly generated without any phase compensation. Our proposal provides a simple technique to generate intense IAPs with various central photon energies covering the multi-keV spectral regime by using multicycle midinfrared driving pulses with high pump energy in the experiment.
190.2620 Harmonic generation and mixing 020.2649 Strong field laser physics 320.2250 Femtosecond phenomena 
Chinese Optics Letters
2017, 15(7): 071901
Author Affiliations
Abstract
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China
Photothermal/photoacoustic (PT/PA) spectroscopy provides useful knowledge about optical absorption, as well as the thermal and acoustical properties of a liquid sample. For microfluidic biosensing and bioanalysis where an extremely small volume of liquid sample is encapsulated, simultaneous PT/PA detection remains a challenge. In this work, we present a new optofluidic device based on a liquid-core optical ring resonator (LCORR) for the investigation of PT and PA effects in fluid samples. A focused 532 nm pulsed light optically heats the absorptive fluid in a capillary to locally create a transient temperature rise, as well as acoustic waves. A 1550 nm CW laser light is quadrature-locked to detect the resonance spectrum shift of the LCORR and study thermal diffusion and acoustic wave propagation in the capillary. This modality provides an optofluidic investigative platform for biological/biochemical sensing and spectroscopy.
230.5750 Resonators 350.5340 Photothermal effects 
Chinese Optics Letters
2017, 15(7): 072301