Employing multiple thin plates instead of a bulk material mitigates large material dispersion and suppresses destructive effects to permit using peak powers up to 1000 times the self-focusing critical power in high-power supercontinuum generation.

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In this work, we generated a supercontinuum source pumped by noise-like pulses from an all-normal dispersion Yb-doped fiber laser. Several kinds of OCT systems were constructed to examine the performance of this new light source, the ultrahigh resolution OCT with axial resolution of 2.3 μm was also demonstrated.

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Beam direction effect was shown to determine the up-conversion efficiency of chirp-PPLN when the infrared pump has spectral width less than that covered by the QPM structure. This phenomenon ceases when the spectral width of the IR beam matches to the QPM bandwidth. The latter can be understood from the structure causality analysis.

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Multi-mode interactions are considered in the numerical model to study stimulated Raman scattering (SRS) in a large-mode-area amplifier, in which excitations of SRS are more efficient as compared to simulation results based on single-mode approximation.

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We present a nonlinear method to design laser resonator with optical elements of inhomogeneous ray transfer matrix for modes of an arbitrary order. By that method, two types resonator modes are classified by the handedness across an intra-cavity spiral wave plate.

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A continuous-wave mode-locking laser via positive cascaded second-order Kerr lens and soft aperture effects at 1063 nm was demonstrated. Under 10 W diode pump power, the measured average power, pulse repetition rate and pulse duration are 1.670 W, 175 MHz and 7.5 ps, respectively.

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We report a 750 nm LED-pumped Nd:YAG laser. By driving the LEDs by 1-ms current pulses, with a current which is 4 times above the allowed CW current. At 10 Hz repetition rate, the laser energy is about 37 uJ/pulse, and the optical efficiency is about 1.05 %.

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We demonstrate millijoule level 1.9 µm pulses by optical parametric chirp pulse amplifier. The pulse energy can be scaled up to 1.07 mJ after amplification. The compressed pulse is 367.8 fs. This mid-infrared source is believed to be the first time of OPCPA in 1.9 µm amplification.

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Thulium is one of the best candidate as an 2 μm laser because of its relatively high quantum efficiency. The purpose of this study is to develop in-house technology for 2 μm Thulium-doped laser fiber for potential biomedical applications, such as high-precision surgery.

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Dynamical grating diffraction experiments have been conducted on azo-dye doped Blue-Phase Liquid Crystal to investigate the mechanisms responsible for laser induced refractive index changes. The underlying mechanisms for the transient grating diffraction components are attributed to thermal indexing and orientational effects.

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4 kHz, 20 ns, pulses with energy up to 1.33 J and wavelengths over 533-553 nm are generated by cascaded (2) processes and applied to optical resolution photoacoustic microscopy of hemoglobin oxygen saturation.

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The lasing quality of whispering-gallery-mode in an individual ZnO microrod were affected by its ambient conditions. We demonstrate that the ZnO microrod entirely surrounded by the air has better optical confinement than that on the Si substrate, which is in agreement with the simulated results.

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We have demonstrated a high power cladding pumped Yb-doped fiber laser generating 400 W of continued-wave (CW) output power at 1080 nm. With all-fiber structure, the laser exhibits good quality and high power efficiency.

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In this paper, we studied spectrally-Gaussian-shaped chirped-pulse amplification of a high-power ytterbium-doped fiber laser. The maximum pulse energy could reach 2.0 microjoule, the peak power and the pulse duration of the best result was ~ 60 kW and 350 fs (FWHM), respectively, with approximately 40% pulse energy in the main pulse.

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In this thesis, I mainly use the cyclic voltammetry (CV) and UV-Visible spectrum to measure the optical properties of polymer light emitting diodes (PLEDs) to compare with the quantum simulation results which are based on time-dependent density functional theories (TD-DFT) for microscopic analysis. PLEDs play an important role in organic electroluminescent (OEL) especially the emitting layer in PLEDs. One of the basic materials to fabricate the emitting layer is the polythiophene (PT). Therefore, it is important to exploit the material properties by experiments and appropriate simulations. In the quantum simulation part, since Gaussian function is not capable of representing periodically molecular structure, the first step is to set up T1(monomer), T2(dimer), until T20 molecular models and then use the regression analysis to predict the band gap of the polythiophene. The absorption energies are then evaluated from the DFT and TD-DFT simulations. In the experimental part, using the cyclic voltammetry by varying the input potential is able to analyze the redox system of the emitting materials and to estimate their band gaps from the V-I plots. The oxidation potential (Eox) and the reduction potential (Ered) can be obtained, and are transformed to the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) accordingly. Finally, through experimental result verifications, this quantum simulation technique is concluded to be reliable and accurate for predicting the optical properties of modern PLEDs.

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An intense 400 nm pump is generated by doing SHG from commercial Ti: Sapphire. The pump passed through a set of fused silica plates and produced a broadband continuum. The coherence, phase, and the M square are further measured in the experiment.

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The electronic properties of silicon nanowires in [100] direction have been calculated using nearest neighbor sp3d5s* tight-binding model. The effect of wire thickness on band gap, effective mass and optical transition has been calculated. Due to the quantum confinement, the one-dimensional Brillouin zone of a Si nanowire changes into direct band gap. And the band gap broadens when the wire size shrinks.

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We report a pulsed IOPO whose output spectrum is EO tailorable based on an APPLN working simultaneously as an OPGM and an active gain spectrum filter in the system. We have obtained from the IOPO the emission of single to multiple narrow-line signal spectral peaks simply by EO control.

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Passive mode-locking laser used graphene as saturable absorber to generate ultrafast pulse. Graphene samples were fabricated by CVD method. The number of layer of graphene saturable absorber has significant influence on laser mode-locking stability and dynamic range. Increased number of layer stacking caused instability and reduced dynamic range in mode-locking laser. However, mode-locking laser was able to generate shorter pulses by employing graphene with more number of layer.

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We report on the development of efficient continuous wave (CW) fiber laser utilizing an Er3+-doped nano-engineered yttria stabilized zirconia–alumino (YZA) silicate fiber. The YZA host presents superior cluster elimination than commercial silica fibers.

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We demonstrated that the crescent wave can be triggered in the vertical cavity surface emitting laser. Near and far fields were investigated. Analysis of stability was also included. Results reveal that elliptical ring with high aspect ratio emerged strong spatial locality and higher output stability under higher current operation.

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We have observed coherent acoustic phonon oscillation in ZnO/ZnMgO multiple quantum wells with pump-probe measurement. With UV femtosecond pulse excitation, photogenerated carriers screen out the strained-induced piezoelectric field and initiate the coherent acoustic-phonon oscillation. As excited photon energy around 3.32 ev, the measured coherent acoustic phonon oscillations about 302 GHz.

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We report experimental observation of lasing on surface states, in the form of standing waves at the termination of a defect-free photonic crystal on top of VCSELs Direct images of lasing modes at the truncated periodic potential, along one side of a square lattice, are demonstrated by collecting near-field radiation patterns, as well as in numerical simulations.

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This paper presents the results of a two-stage oscillator/amplifier radio frequency power supply for driving compact CO2 lasers. The main characteristic of this power supply is simple and inexpensive in the facts based on MOSFET technology. RF output power is above 300W centered at 100MHz frequency signal.

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We integrate Finite-Difference model and Kruskal-Wallis method to analyze two-section DFB self-sustaining-pulsation lasers periodic output stability. Systematic integrating such two methods in optical signals process is different to the existed researches.

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