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Chinese Optics Letters 第12卷 第4期

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 College of Physics and Electronic Information Engineering, Wenzhou University, Wenzhou 325035, China
3 School of Physical Science and Technology, Shanghai Tech University, Shanghai 200031, China
A new polarization gating is demonstrated by our principle-of-proof experiment, which is theoretically proposed to generate the isolated or double attosecond pulses with the multi-cycle driving laser pulse in the previous work [Optics Express. 20, 5196 (2012)]. In the experiment, the polarization gating is formed by two orthogonally-polarized linearly chirped multi-cycle laser pulses, and the spectral bandwidths of the harmonics are broadened by more than two times, which agree with the previous theoretical work.
020.1335 Atom optics 020.2649 Strong field laser physics 190.2620 Harmonic generation and mixing 
Chinese Optics Letters
2014, 12(4): 040201
Author Affiliations
Abstract
An integrated method based on optical and digital image processing is presented to suppress speckle in digital holography. A spatial light modulator is adopted to introduce random phases to the illuminating beam. Multiple holograms are reconstructed and superimposed, and the intensity is averaged to smooth the noise. The adaptive algorithm based on the nonlocal means is designed to further suppress the speckle. The presented method is compared with other methods. The experimental results show that speckle reduction is improved, and the proposed method is effective and feasible.
030.6140 Speckle 090.1995 Digital holography 100.2000 Digital image processing 
Chinese Optics Letters
2014, 12(4): 040301
Author Affiliations
Abstract
Two-dimensional metallic photonic crystal slabs with square lattice are proposed to be used for the design of waveguide bandpass filters operating in millimeter to terahertz region. Filter characteristics are studied when rod radii and lattice constants are changed. Based on the frequency scaling technique, a series of higher frequency filters has been designed. By using laser drilling and welding processing techniques, a compact waveguide filter embedded in an EIA-WR10 waveguide with central frequency 145.5 GHz and 3-dB bandwidth of 5.26 GHz is fabricated and measured. The measurement data agree well with the simulation prediction.
040.2235 Far infrared or terahertz 120.2440 Filters 050.5298 Photonic crystals 120.7000 Transmission 
Chinese Optics Letters
2014, 12(4): 040401
Author Affiliations
Abstract
A series of Alx-(Alq3)1-x granular films is prepared on Si wafer with native oxide layer using co-evaporation technique. Large lateral photovoltaic effect (LPE) is observed, with an optimal LPV sensitivity of 75 mV/mm in x = 0.35 sample. The dependence of LPE on temperature and Al composition is investigated, and the possible mechanism is discussed.
040.5160 Photodetectors 040.5350 Photovoltaic 160.4890 Organic materials 
Chinese Optics Letters
2014, 12(4): 040402
Author Affiliations
Abstract
By using PDM-OFDM-16QAM modulation, all-Raman amplification, coherent detection, and 7% forward error correction (FEC) threshold, we successfully demonstrate 63-Tb/s (368×183.3-Gb/s) signal over 160-km standard single mode fiber (SSMF) transmission in the C- and L-bands with 25-GHz channel spacing. 368 optical channels with bandwidth spacing of 25 GHz are generated from 16 external cavity laser sources. After 160-km SSMF transmission, all tested bit error rate (BER) are under 3.8×10-3, which can be recovered by 7% FEC threshold. Within each channel, we achieve the spectral efficiency of 6.85 bit/s/Hz in C/L band.
060.0060 Fiber optics and optical communications 250.0250 Optoelectronics 070.0070 Fourier optics and signal processing 
Chinese Optics Letters
2014, 12(4): 040601
Author Affiliations
Abstract
This letter reports a study of a hybrid burst assembly and a hybrid burst loss recovery scheme (delay-based burst assembly and hybrid loss recovery (DBAHLR)) which selectively employs proactive or reactive loss recovery techniques depending on the classification of traffic into short term and long term, respectively. Traffic prediction and segregation of optical burst switching network flows into the long term and short term are conducted based on predicted link holding times using the hidden Markov model (HMM). The hybrid burst assembly implemented in DBAHLR uses a consecutive average-based burst assembly to handle jitter reduction necessary in real-time applications, with variations in burst sizes due to the non-monotonic nature of the average delay handled by additional burst length thresholding. This dynamic hybrid approach based on HMM prediction provides overall a lower blocking probability and delay and more throughput when compared with forward segment redundancy mechanism or purely HMM prediction-based adaptive burst sizing and wavelength allocation (HMM-TP).
060.4250 Networks 060.4510 Optical communications 
Chinese Optics Letters
2014, 12(4): 040602
Author Affiliations
Abstract
This letter presents a low cost solution for wavelength division multiplexed orthogonal frequency division multiplexed passive optical network (WDM-OFDM-PON) with widely tunable optical filter and linear small form-factor pluggable (SFP) module. With 9-nm tunable range from 1551 to 1560 nm, the tunable filter can support up to 10-channel 100-GHz spacing WDM PON system. A linear avalanche photodiode (APD) based SFP+ module is designed for optical OFDM signal demodulation, which can provide better receiver performance compared with limiting APD module. Experimental results show that ~34 dB power budget can be achieved in 4×5-Gbps WDM-OFDM-PON system, which can satisfy the transmission requirements of next generation PON system.
060.2330 Fiber optics communications 060.2360 Fiber optics links and subsystems 
Chinese Optics Letters
2014, 12(4): 040603
Author Affiliations
Abstract
We demonstrate a digital optical communication system based on minimum shift keying (MSK) signal transmission with coherent detection. 5-Gb/s MSK signal can transmit over a 160-km standard single mode fiber (SSMF) without phase compensation. At the receiver, we use data-aided channel estimation and frequency domain equalization (FDE) techniques in the digital signal processing (DSP) algorithm, then analyze its performance characteristics compared with quadrature phase shift keying (QPSK) format. The simulation results show that the MSK format will be a potential candidate for next-generation access network.
060.2330 Fiber optics communications 060.2360 Fiber optics links and subsystems 060.1660 Coherent communications 
Chinese Optics Letters
2014, 12(4): 040604
Author Affiliations
Abstract
DNA tetrahedral nanostructures are considered to be new nanocarriers because they can be precisely controlled and hold excellent penetration ability to the cellular membrane. Although the DNA tetrahedral nanostructure is extensively studied in biology and medicine, its behavior in the cells with nanoscale resolution is not understood clearly. In this letter, we demonstrate superresolution fluorescence imaging of the distribution of DNA tetrahedral nanostructures in the cell with a simulated emission depletion (STED) microscope, which is built based on a conventional confocal microscope and can provide a resolution of 70 nm.
110.0180 Microscopy 100.6640 Superresolution 180.2520 Fluorescence microscopy 
Chinese Optics Letters
2014, 12(4): 041101
Author Affiliations
Abstract
We report a line-narrowed electro-optic periodically-poled-lithium-niobate (PPLN) Q-switched laser with intra-cavity optical parametric oscillation using a grazing-incidence grating, producing 8-ns, 5-\mu J pulses at 10-kHz repetition rate when pumped with a 10-W diode laser at 808 nm. The output wavelength is centered at 1554.3 nm with a 0.03-nm spectral width. Wavelength tuning is achieved by rotating a mirror and changing the crystal temperature.
140.3480 Lasers, diode-pumped 140.3540 Lasers, Q-switched 190.4975 Parametric processes 
Chinese Optics Letters
2014, 12(4): 041401
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
In this letter, we report a multifunctional high-performance Nd:glass laser system. Laser pulses from an all-fiber front end are first amplified by a regenerative amplifier to 10 mJ level, and then further amplified in a four-pass amplifier. The laser system can provide 10.3-J, 3-ns laser pulses at 1053-nm wavelength. The shot-to-shot energy stability is better than 1.5% (RMS). The output laser beam is near diffraction limit. Binary amplitude masks are used to maintain a flat top near-field profile with a 71% fill factor. After the frequency conversion process, 7 and 5.5 J pulses at 526.5 and 351 nm are obtained, respectively.
140.3280 Laser amplifiers 140.3580 Lasers, solid-state 140.3538 Lasers, pulsed 
Chinese Optics Letters
2014, 12(4): 041402
Author Affiliations
Abstract
Fe-Mn-Si-Cr-Ni composite powders are utilized to form a functional shape memory alloy cladding layer (SMACL) using a laser cladding method. The microstructure, microhardness, and phase composition of the SMACL are measured, and the extent of deformation of the laser cladding samples is determined. The SMACL is composed of planar, cellular, and dendritic crystals, equiaxed grains, and oxides with increasing distance from the substrate surface. The SMACL is further composed of \varepsilon -martensite and \gamma -austenite phases, while the tempered SMACL consists mainly of \gamma -austenite. Extensive deformation occurs in AISI 304 stainless steel laser cladding samples. By contrast, limited deformation is observed in the SMACL samples.
140.3390 Laser materials processing 160.3900 Metals 350.3850 Materials processing 
Chinese Optics Letters
2014, 12(4): 041403
Author Affiliations
Abstract
Transmission and negative refractive index (NRI) of metal-dielectric-metal (MDM) metamaterials perforated with different thickness of dielectric layer are studied. It can be found that transmission peaks of rectangular hole are sensitive to the thickness of the dielectric layer. NRI and the bandwidth of NRI are increased with the increasing of the thickness of dielectric layer. NRI of rectangular hole with the thickness of dielectric layer almost follows a linear law when the thickness of dielectric layer in 2–5 μm. A high NRI of metamateriral can be obtained by adjusting the thickness of the dielectric layer of the rectangular hole on MDM metamateriral arrays.
160.3918 Metamaterials 160.4236 Nanomaterials 260.1180 Crystal optics 260.3910 Metal optics 160.5298 Photonic crystals 
Chinese Optics Letters
2014, 12(4): 041601
Author Affiliations
Abstract
Different from the cases discussed preciously, nonlinear changes of refractive index in the photorefractive materials are influenced by both the linear and quadratic electro-optic effect simultaneously now. Here we present the evolution equations of one-dimension incoherently coupled spatial soliton families due to two-photon effect in biased photorefractive crystals with both the linear and quadratic electro-optic effect and discuss their existence conditions and properties in detail. Our analysis indicates that these soliton families can exist in all three possible realizations: dark-dark, bright-bright and dark-bright provided that the incident beams have the same polarization, wavelength and are mutually incoherent. Finally, the stabilities of these soliton families have been discussed by means of beam propagation methods.
190.0190 Nonlinear optics 190.5330 Photorefractive optics 190.6135 Spatial solitons 160.2100 Electro-optical materials 
Chinese Optics Letters
2014, 12(4): 041901
Author Affiliations
Abstract
Transmission and reflection of an electromagnetic pulse through a dielectric slab doped with the quantum dot molecules are investigated. It is shown that the transmission and reflection coefficients depend on the inter-dot tunneling effect and can be simply controlled by applying a gate voltage without any changing in the refractive index or thickness of the slab. Such simple controlling prepares an active beam splitter which can be used in all optical switching, optical limiting, and other optical systems.
260.2110 Electromagnetic optics 250.5590 Quantum-well, -wire and -dot devices 020.1670 Coherent optical effects 310.6860 Thin films, optical properties 
Chinese Optics Letters
2014, 12(4): 042601
Author Affiliations
Abstract
1 National Laboratory on High Power Laser and Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
Temporal and spatial optical field distributions of a stepped pulse on the hohlraum wall are numerically analyzed using fast-Fourier-transform method combined with chromatographic theory. Changes in the rising edge of the stepped pulse caused by spatio-temporal effect are systematically studied. Results demonstrate that a certain time difference exists for the laser to reach the hohlraum wall because of oblique incidence, which causes distortion to the stepped pulse, especially to the rising edge. Influences of the incident angle, focal length, and width of the input rising edge on distortion degree of the stepped pulse are also discussed. This letter provides some guidance for targeting pulse shaping and synchronization.
260.1960 Diffraction theory 250.5530 Pulse propagation and temporal solitons 320.5540 Pulse shaping 
Chinese Optics Letters
2014, 12(4): 042602
Author Affiliations
Abstract
We describe a surface plasmon resonance-based fiber sensor based on a side-polished graded-index multimode fiber, in which an Al-doped zinc oxide/gold (AZO/Au) bilayer is deposited on the side-polished surface of the fiber core to improve the detection sensitivity of the device. The AZO/Au layer is used as the active sensing member of the device with a combination of a 75-nm-thick AZO layer and a 40-nm-thick Au layer. Such a device is then applied to the concentration measurement of CH3COONa solutions, as an example showing a good response to concentration variation. The results indicate that the additional AZO layer in the active sensing member may lead to higher detection sensitivity and greater measurement stability in the measurements of solution concentration.
280.4788 Optical sensing and sensors 060.2370 Fiber optics sensors 
Chinese Optics Letters
2014, 12(4): 042801
Author Affiliations
Abstract
This paper proposes the post-integration technology based on sub-pixel image registration and image fusion to improve the signal-to-noise ratio (SNR) of remote sensing images without motion degradation caused by satellite vibration. A two-dimensional vibration system is set up to simulate satellite disturbance. Image sequences with different exposure times are captured using a high-speed CMOS camera. The displacement plots are compared with the motion data measured by the grating linear encoder. These plots indicate that the accuracy of the registration algorithm is better than 0.1 pixels. The sub-pixel image fusion shows an improvement in image quality, thus indicating that this technology is powerful for staring imaging systems in geostationary orbit.
280.4788 Optical sensing and sensors 110.4153 Motion estimation and optical flow 110.4155 Multiframe image processing 
Chinese Optics Letters
2014, 12(4): 042802
Author Affiliations
Abstract
A novel high-throughput spectrometer with a wide-slit is presented. In conventional spectrometers, the slit limited the light throughput. Here, the slit is replaced with a much wider one (200 μm) to increase throughput. A beam splitter is utilized to construct a dual-path optics to measure both non-dispersed and dispersed light intensity which comes from the wide-slit. While the dispersed light intensity is result of the non-dispersed light convoluted spectrum of the source, the spectrum can be acquired by solving the inverse problem of deconvolution. Experiments show that the reconstructed spectra achieved almost the same resolution measured by traditional spectrometer, while throughput and peak signal-to-noise ratio (PSNR) are improved dramatically.
300.6190 Spectrometers 100.6640 Superresolution 100.3190 Inverse problems 
Chinese Optics Letters
2014, 12(4): 043001
Author Affiliations
Abstract
A polymethyl-methacrylate (PMMA) acrylic sample cell using flow injection is developed in this research for the determination of nitrite in an aqueous media. The research focuses on exhibiting direct absorbance spectrophotometry of nitrite using concentration of samples ranging from 0.1078 to 1.725 ppm. Nitrite determination is done colorimetrically using the Greiss reagent method. This method is based on the reaction of nitrite with sulphanilamide acid and N-1-napthylamine (NED) utilizing diazo coupling, and a syringe is used to administer the nitrite solution. The sample cell being used possesses a diameter of 1 mm with an overall size of 7.35×22 mm2. To gauge the direct absorbance, a wavelength range from 400 to 650 nm has been selected for the testing, and the maximum absorbance is found to be at 545 nm. The validity of the proposed cell is explained in this letter.
300.1030 Absorption 280.4788 Optical sensing and sensors 120.0120 Instrumentation, measurement, and metrology 
Chinese Optics Letters
2014, 12(4): 043002