2015, 3(2) Column
Photonics Research 第3卷 第2期
Investigation on random distributed feedback Raman fiber laser with linear polarized outputDownload:825次
A random distributed feedback fiber laser with linear polarized output at 1178 nm is presented. Linear polarization is realized by fiber coiling in a half-opened cavity of a polarization maintaining random fiber laser structure. The single linear polarization laser output power reaches ~3 W with polarization extinction ratio >14 dB. Further investigations on the coiling technique and additional feedback are also studied. So far as we know, this is the first reported linear polarized random distributed feedback Raman fiber laser.
Lasers Lasers distributed-feedback distributed-feedback Fibers Fibers polarization-maintaining polarization-maintaining Scattering Scattering Rayleigh Rayleigh Photonic crystal slabs integrated into organic light-emitting diodes (OLEDs) allow for the extraction of waveguide modes and thus an increase in OLED efficiency. We fabricated linear Bragg gratings with a 460-nm period on flexible polycarbonate substrates using UV nanoimprint lithography. A hybrid organic–inorganic nanoimprint resist is used that serves also as a high refractive index layer. OLEDs composed of a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) polymer anode, an organic emission layer [poly(p-phenylene vinylene) (PPV)-derivative “Super Yellow”], and a metal cathode (LiF/Al) are deposited onto the flexible grating substrates. The effects of photonic crystal slab deformation in a flexible OLED are studied in theory and experiment. The substrate deformation is modeled using the finite-element method. The influence of the change in the grating period and the waveguide thickness under bending are investigated. The change in the grating period is found to be the dominant effect. At an emission angle of 20° a change in the resonance wavelength of 1.2% is predicted for a strain of 1.3% perpendicular to the grating grooves. This value is verified experimentally by analyzing electroluminescence and photoluminescence properties of the fabricated grating OLEDs.
Gratings Gratings Photonic crystals Photonic crystals Light-emitting diodes Light-emitting diodes Organic materials Organic materials Polymers Polymers Photoluminescence Photoluminescence Raman tensor of AlN bulk single crystalDownload:757次
The angle dependence of optical phonon modes of an AlN bulk single crystal from the m-plane (1100) and c-plane (0001) surfaces, respectively, is investigated by polarized Raman spectroscopy in a backscattering configuration at room temperature. Corresponding Raman selection rules are derived according to measured scattering geometries to illustrate the angle dependence. The angle-dependent intensities of phonon modes are discussed and compared to theoretical scattering intensities, yielding the Raman tensor elements of A1(TO), E22 , E1(TO), and A1(LO) phonon modes and the relative phase difference between the two complex elements of A1_TO_. Furthermore, the Raman tensor of wurtzite AlN is compared with that of wurtzite ZnO reported in previous work, revealing the intrinsic differences of lattice vibration dynamics between AlN and ZnO.
Semiconductor materials Semiconductor materials Scattering Scattering Raman Raman Scattering Scattering polarization polarization The comparative numerical and analytical analysis of scintillation indices of the vortex Laguerre–Gaussian beam and the nonvortex doughnut hole and Gaussian beams propagating in the randomly inhomogeneous atmosphere has been performed. It has been found that the dependence of the scintillation index at the axis of the optical vortex on the turbulence intensity at the path has the form of a unit step. It has been shown that the behavior of scintillations in the cross sections of vortex and nonvortex beams differs widely. Despite the scintillation index of vortex beams has been calculated only for the simplest LG10 mode, the obtained results are quite general, because they demonstrate the main properties inherent in scintillations of vortex beams of any type.
Atmospheric propagation Atmospheric propagation Atmospheric turbulence Atmospheric turbulence Coherence Coherence Optical vortices Optical vortices Singular optics Singular optics Speckle Speckle Sign of differential reflection and transmission in pump-probe spectroscopy of graphene on dielectric substrateDownload:1124次
Pump-probe differential reflection and transmission spectroscopy is a very effective tool to study the nonequili-brium carrier dynamics of graphene. The reported sign of differential reflection from graphene is not explicitly explained and not consistent. Here, we study the differential reflection and transmission signals of graphene on a dielectric substrate. The results reveal the sign of differential reflection changes with the incident direction of the probe beam with respect to the substrate. The obtained theory can be applied to predict the differential signals of other two-dimensional materials placed on various dielectric substrates.
Thin films Thin films other properties other properties Nonlinear optics Nonlinear optics materials materials Optical properties Optical properties Ultrafast nonlinear optics Ultrafast nonlinear optics Due to the manifestation of fascinating physical phenomena and materials science, two-dimensional (2D) materials have recently attracted enormous research interest with respect to the fields of electronics and optoelectronics. There have been in-depth investigations of the nonlinear properties with respect to saturable absorption, and many 2D materials show potential application in optical switches for passive pulsed lasers. However, the Eigen band-gap determines the responding wavelength band and constrains the applications. In this paper, based on band-gap engineering, some different types of 2D broadband saturable absorbers are reviewed in detail, including molybdenum disulfide (MoS2), vanadium dioxide (VO2), graphene, and the Bi2Se3 topological insulator. The results suggest that the band-gap modification should play important roles in 2D broadband saturable materials and can provide some inspiration for the exploration and design of 2D nanodevices.
Lasers and laser optics Lasers and laser optics Lasers Lasers Q-switched Q-switched Laser materials Laser materials Lasers Lasers pulsed pulsed We propose and demonstrate a dual-wavelength single-longitudinal-mode (SLM) fiber laser with switchable wavelength spacing based on a graphene saturable absorber (GSA) and a WaveShaper. By virtue of the excellent saturable absorption ability of graphene, the linewidths of the lasing wavelengths can be effectively reduced and eventually SLM operation can be obtained. The linewidths of both wavelengths are measured to be narrower than 7.3 kHz. The obtained results suggest that the graphene would be a good candidate nonlinear optical material for applications in related photonic fields, such as SLM oscillation generation for microwave generation and optical sensing.
Lasers Lasers fiber fiber Lasers Lasers single-mode single-mode Nonlinear optical materials Nonlinear optical materials Nanosecond-pulsed, dual-wavelength, passively Q-switched ytterbium-doped bulk laser based on few-layer MoS2 saturable absorberDownload:1062次
A compact saturable absorber mirror (SAM) based on few-layer molybdenum disulfide (MoS2) nanoplatelets was fabricated and successfully used as an efficient saturable absorber (SA) for the passively Q-switched solid-state laser at 1 μm wavelength. Pulses as short as 182 ns were obtained from a ytterbium-doped (Yb:LGGG) bulk laser Q-switched by the MoS2 SAM, which we believe to be the shortest one ever achieved from the MoS2 SAs-based Q-switched bulk lasers. A maximum average output power of 0.6 W was obtained with a slope efficiency of 24%, corresponding to single pulse energy up to 1.8 μJ. In addition, the simultaneous dual-wavelength Q-switching at 1025.2 and 1028.1 nm has been successfully achieved. The results indicate the promising potential of few-layer MoS2 nanoplatelets as nonlinear optical switches for achieving efficient pulsed bulk lasers.
Lasers Lasers solid-state solid-state Nonlinear optical materials Nonlinear optical materials Nanomaterials Nanomaterials Few-layer MoS2 saturable absorbers for short-pulse laser technology: current status and future perspectives [Invited]Download:1011次
Few-layer molybdenum disulfide (MoS2) is emerging as a promising quasi-two-dimensional material for photonics and optoelectronics, further extending the library of suitable layered nanomaterials with exceptional optical properties for use in saturable absorber devices that enable short-pulse generation in laser systems. In this work, we catalog and review the nonlinear optical properties of few-layer MoS2, summarize recent progress in processing and integration into saturable absorber devices, and comment on the current status and future perspectives of MoS2-based pulsed lasers.
Lasers Lasers pulsed pulsed Nanomaterials Nanomaterials Nonlinear optical materials Nonlinear optical materials Nonlinear optical devices Nonlinear optical devices Soliton fiber laser mode locked with two types of film-based Bi2Te3 saturable absorbersDownload:757次
We propose a low-threshold soliton fiber laser passively mode locked with two different types of film-like saturable absorbers, one of which is fabricated by mixing Bi2Te3 with de-ionized water, as well as polyvinyl alcohol (PVA), and then evaporating them in a Petri dish, and the other of which is prepared by directly dropping Bi2Te3 solution on the PVA film. Both Bi2Te3–PVA films exhibit outstanding features of low loss, high flexibility, and easy synthesis. By incorporating Bi2Te3–PVA films into fiber lasers, stable single-soliton emissions are obtained at a low pump power of 13 mW. Our results suggest that the Bi2Te3 can work as a promising mode locker for ultrafast lasers, while PVA is an excellent host for fabricating high-performance film-based saturable absorbers.
Mode-locked lasers Mode-locked lasers Lasers Lasers fiber fiber Nanomaterials Nanomaterials Ultrafast nonlinear optics Ultrafast nonlinear optics Passive Q-switching and Q-switched mode-locking operations of 2 μm Tm:CLNGG laser with MoS2 saturable absorber mirrorDownload:797次
With MoS2 as saturable absorber, passive Q-switching and Q-switched mode-locking operations of a Tm-doped calcium lithium niobium gallium garnet (Tm:CLNGG) laser were experimentally demonstrated. The Q-switched laser emitted a maximum average output power of 62 mW and highest pulse energy of 0.72 μJ. Q-switched mode locking was also obtained in the experiment. The research results will open up applications of MoS2 at the mid-infrared wavelength.
Lasers Lasers Q-switched Q-switched Lasers Lasers solid-state solid-state Tunable nonlinear refractive index of two-dimensional MoS2, WS2, and MoSe2 nanosheet dispersions [Invited]Download:1570次
Liquid-phase-exfoliation technology was utilized to prepare layered MoS2, WS2, and MoSe2 nanosheets in cyclohexylpyrrolidone. The nonlinear optical response of these nanosheets in dispersions was investigated by observing spatial self-phase modulation (SSPM) using a 488 nm continuous wave laser beam. The diffraction ring patterns of SSPM were found to be distorted along the vertical direction right after the laser traversing the nanosheet dispersions. The nonlinear refractive index of the three transition metal dichalcogenides dispersions n2 was measured to be ~10 7 cm2·W 1, and the third-order nonlinear susceptibility χ(3) ~ 10 9 esu. The relative change of effective nonlinear refractive index Δn2e∕n2e of the MoS2, WS2, and MoSe2 dispersions can be modulated 0.012– 0.240, 0.029–0.154, and 0.091–0.304, respectively, by changing the incident intensities. Our experimental results imply novel potential application of two-dimensional transition metal dichalcogenides in nonlinear phase modulation devices.
Nonlinear optics Nonlinear optics Nanomaterials Nanomaterials Nonlinear optical materials Nonlinear optical materials Mode-locking of fiber lasers using novel two-dimensional nanomaterials: graphene and topological insulators [Invited]Download:1215次
The paper summarizes the recent achievements in the area of ultrafast fiber lasers mode-locked with so-called lowdimensional nanomaterials: graphene, topological insulators (Bi2Te3, Bi2Se3, Sb2Te3), and transition metal sulfide semiconductors, like molybdenum disulfide (MoS2). The most important experimental achievements are described and compared. Additionally, new original results on ultrashort pulse generation at 1.94 μm wavelength using graphene are presented. The designed Tm-doped fiber laser utilizes multilayer graphene as a saturable absorber and generates 654 fs pulses at 1940 nm wavelength, which are currently the shortest pulses generated from a Tm-doped fiber laser with a graphene-based saturable absorber.
Mode-locked lasers Mode-locked lasers Lasers Lasers fiber fiber Lasers Lasers fiber fiber A graphene-coated microfiber (GCM)-based hybrid waveguide structure formed by wrapping monolayer graphene around a microfiber with length of several millimeters is pumped by a nanosecond laser at ~1550 nm, and multiorder cascaded four-wave-mixing (FWM) is effectively generated. By optimizing both the detuning and the pump power, such a GCM device with high nonlinearity and compact size would have potential for a wide range ofFWM applications, such as phase-sensitive amplification, multi-wavelength filter, all-optical regeneration and frequency conversion, and so on.
Nonlinear wave mixing Nonlinear wave mixing Optical materials Optical materials Guided waves Guided waves Few-layer MoS2-deposited microfiber as highly nonlinear photonic device for pulse shaping in a fiber laser [Invited]Download:757次
Two-dimensional (2D) materials have emerged as attractive mediums for fabricating versatile optoelectronic devices. Recently, few-layer molybdenum disulfide (MoS2), as a shining 2D material, has been discovered to possess both the saturable absorption effect and large nonlinear refractive index. Herein, taking advantage of the unique nonlinear optical properties of MoS2, we fabricated a highly nonlinear saturable absorption photonic device by depositing the few-layer MoS2 onto the microfiber. With the proposed MoS2 photonic device, apart from the conventional soliton patterns, the mode-locked pulses could be shaped into some new soliton patterns, namely, multiple soliton molecules, localized chaotic multipulses, and double-scale soliton clusters. Our findings indicate that the few-layer MoS2-deposited microfiber could operate as a promising highlynonlinear photonic device for the related nonlinear optics applications.
Nonlinear optical materials Nonlinear optical materials Pulse propagation and temporal solitons Pulse propagation and temporal solitons Lasers Lasers fiber fiber Mode-locked lasers Mode-locked lasers We propose and demonstrate a dual-wavelength single-longitudinal-mode (SLM) fiber laser with switchable wavelength spacing based on a graphene saturable absorber (GSA) and a WaveShaper. By virtue of the excellent saturable absorption ability of graphene, the linewidths of the lasing wavelengths can be effectively reduced and eventually SLM operation can be obtained. The linewidths of both wavelengths are measured to be narrower than 7.3 kHz. The obtained results suggest that the graphene would be a good candidate nonlinear optical material for applications in related photonic fields, such as SLM oscillation generation for microwave generation and optical sensing.
Lasers Lasers fiber fiber Lasers Lasers single-mode single-mode Nonlinear optical materials Nonlinear optical materials 公告
动态信息
动态信息 丨 2024-04-25
PR Highlight (Vol. 12, Iss. 2): 封面|超紧凑片上偏振控制器动态信息 丨 2024-04-11
PR Highlight (Vol. 11, Iss. 12): 亮点 | 十亿像素级、高通量的无透镜偏振编码叠层成像技术动态信息 丨 2024-03-29
PR 封面故事 (Vol. 12, Iss. 3): 封面 | 基于时空编码神经网络的像差感知超分辨成像动态信息 丨 2024-03-25
PR 封面故事 (Vol. 12, Iss. 1) 光涡旋与手性器件微纳3D打印动态信息 丨 2024-03-14
PR Highlight (Vol. 12, Iss. 1): 同步双脉冲激光烧蚀中的气泡相互作用效应激光评论微信公众号
点击菜单“联系编辑”即可添加期刊编辑为好友啦