Cylindrical vector beams (CVBs) have attracted immense recent attention for material processing and particle manipulation. High power output is the base of CVB lasers those applications. The traditional path to obtain high laser cooperation high-order mode (HOM) amplifier seed source, which a complex non-integrated system. This work proposed compact with an oscillator integrated into one fiber cavity. In cavity, fundamental resonant, HOM escapes in leaky mode. Tunable slope efficiency are...

A frequency-modulated continuous-wave (FMCW) lidar is proposed to avoid signal aliasing in the measurement of distance and velocity. In transmitter, a lightwave amplitude-modulated Mach-Zehnder modulator by linear-frequency modulated (LFM) waveform. The light used as probe signal. reflected optical beats with local (LO) phase-diversity coherent receiver. in-phase quadrature components output are simultaneously recorded. extracted from sum squares two components, while velocity calculated...

The entire decaying dynamics of harmonic mode-locking (HML) are studied utilizing the dispersive Fourier transform (DFT) technique in a SESAM-based mode-locked fiber laser. It is unveiled that solitons do not disappear directly, but undergo transitional processes from higher-order HML to lower-order and then fundamental (FML), finally vanish. “big corner” can also exist process rather than just buildup HML, there at least one during between consecutive multi-pulsing states. energy...

Ultrafast transient absorption spectroscopy is a powerful tool to reveal excited state dynamics in various materials. Conventionally, probe pulses are generated via bulk supercontinuum generation or (noncollinear) optical parametric amplifiers whilst pump separately using amplifiers. These systems limited by either their spectral density, stability, range, and/or temporal compressibility. Recently, new intense broadband light source being developed, the multi-plate compression, which...

A multifunction lidar system is proposed based on polarization-division multiplexing, by which the distance, velocity, and depolarization ratio of a target can be simultaneously measured. The key component multiplexing dual-drive Mach-Zehnder modulator (PDM-DMZM). linear frequency-modulated (LFM) waveform applied to one sub-DMZM PDM-DMZM modulate light along polarization direction, while single-frequency RF signal other orthogonal direction. As result, dual-polarization beam containing both...

A frequency-modulated continuous-wave (FMCW) coherent lidar with downlink communication capability is proposed based on phase-diversity detection, by which laser ranging, velocimetry and free-space optical communications can be simultaneously achieved. In the local transceiver, a linear-frequency modulated (LFM) signal generated used as signal. The LFM received remote transceiver coded data via amplitude modulation. Then, light transmitted back to in receiver extract range, velocity, data....

To analyze the composition of lunar surface minerals, one scientific payloads Chang'E 3 Yutu rover, Visible and Near-infrared Imaging Spectrometer (VNIS), was developed to detect objects obtain their reflectance spectra geometric images. The VNIS, which uses acousto-optic tunable filters as dispersive components, consists a VIS/NIR imaging spectrometer (0.45-0.95 μm), shortwave IR (0.9-2.4 calibration unit with dust-proofing functionality. It is capable synchronously acquiring full...

The vortex beam (Laguerre-Gaussian, LG10 mode) is employed to alleviate crystal damage in multiple-plate continuum generation. We successfully compressed 190-fs, 1030-nm pulses 42 fs with 590 μJ input pulse energy, which 5.5 times higher than that obtained by a Gaussian setup of the same footprint. High throughput (86%) and high intensity-weighted homogeneity (>98%) have also been achieved. This experiment confirms great potential shaping energy up-scaling nonlinear compression.

A compact all-fiber polarization coherent Lidar is demonstrated to simultaneously measure the velocity and depolarization ratio. In system, a dual-polarization light beam generated in modulator (PolM). The consists of linearly polarized optical carrier an sideband with orthogonal state. If depolarized, directions are rotated. Both them can be detected along direction original carrier. receiver, backscattered selected beats frequency-shifted local oscillator (LO) signal at photodetector. beat...

A near-resonant, red-detuning laser-assisted Stark deceleration scheme is proposed to slow CaF in its high-field-seeking rovibronic ground state. The assisting Gaussian laser beam can confine molecules transversely owing the optical effect. Simulations suggest that present superior previous decelerators. Under typical experimental conditions, when frequency red-detuned molecular transition (λ ∼606.3 nm) by 5.0 GHz and power about 5.6 W, decelerator achieve a total number at order of 104 with...

Mid-infrared (MIR) pulsed lasers near a 3 µm waveband show great potential for the high absorption of water molecules and many important gas molecules. A passively Q-switched mode-locked (QSML) Er3+-doped fluoride fiber laser with low threshold slope efficiency around 2.8 is reported. The improvement achieved by depositing bismuth sulfide (Bi2S3) particles onto cavity mirror directly as saturable absorber using cleaved end output directly. -QSML pulses begin to appear pump power 280 mW....

We have developed a temporal coupled-mode theory based on quasi-normal modes to investigate the chiroptical effects in parity-time (PT) symmetric metasurfaces. The PT symmetry enforces different constraint for direct scattering matrix and coupling constants, which is verified by calculating transmission spectra originating from chiral quasi-bound states continuum. What's more, can be analytically continued complex frequency plane. find that zero pole singularities of coefficients play an...

Optical trapping and manipulating of micron-sized particles have attracted enormous interests due to the potential applications in biotechnology nanoscience. In this work, we investigate numerically theoretically radiation forces acting on a Rayleigh dielectric particle produced by beams generated Gaussian mirror resonator (GMR) scattering regime. The results show that focused GMR can be used trap manipulate with both high low index refractive near focus point. influences optical parameters...

A frequency-modulated continuous-wave laser ranging method using low-duty-cycle linear-frequency-modulated (LFM) signals is proposed. spectrum consisting of a dense Kronecker comb obtained so that the frequency beat signal can be measured with finer resolution. Since provided, super-resolved achieved single-parametric estimation method. Therefore, run times are reduced which promises real-time applications. proof-of-concept experiment carried out, in an LFM bandwidth 5 GHz and duration 1 µs...

A fiber-based beam shaper to adjust the distribution of spatial modes in a few-mode fiber (FMF) is theoretically and experimentally investigated this work. compact robust device, composed with single mode fiber-graded index multimode fiber-few (SMF-GIMF-FMF), fabricated by simply fusion splicing fibers. Switchable multi-wavelength comb are obtained combination Bragg grating (FM-FBG). This acts as filter select wavelength laser. switchable laser high purity extended among LP 01 , 11...

Abstract Ultrafast transient absorption spectroscopy is a powerful tool to reveal excited state dynamics in various materials. Conventionally, probe pulses are generated via bulk supercontinuum generation or (noncollinear) optical parametric amplifiers whilst pump separately from amplifiers. These systems limited by either their spectral density, stability, range, and/or temporal compressibility. Recently, new intense broadband light source being developed, the multi plate compression, which...

Digital signals are encoded via amplitude modulation on the LFM optical signal of an FMCW lidar. The distance and data simultaneously extracted without crosstalk. transmission is not influenced by Doppler Effect.

Harmonic mode-locking (HML) is realized in a thulium-doped fiber laser (TDFL) using indium sulfate (In2(SO4)3) as saturable absorber (SA). The In2(SO4)3 has nonlinear absorption properties with the optical modulation depth of 13.3 % and saturation power 0.11 kW at 1930 nm. fundamentally mode-locked pulses operate 1964.44 nm have 3-dB bandwidth 4.70 nm, pulse width 1.266 ps, repetition rate 25.37 MHz. maximum resonance frequency 228 MHz achieved, which corresponds to 9th harmonic. supermode...

The degradation mechanism of fluorine treated enhancement-mode (E-mode) AlGaN/GaN high electron mobility transistors (HEMTs) under reverse gate bias was studied in this paper. experimental results show that E-mode HEMTs using ion implantation shows a significant negative shift threshold voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) during the long-term bias. Three main mechanisms are used to explain phenomenon. In paper,...

We have developed a new method, transient grating photoluminescence spectroscopy (TGPLS), allowing the collection of broadband ultrafast with low background. In TGPLS, two laser pulses generate multiplexed (TG) by optical Kerr effect. The gated signal is diffracted TG and spatially separated from background fluorescence. This high performance nonlinear gate delivers time resolution less than 200 fs, spectral bandwidth covering entire visible region extremely fluorescence Here we present...