We discovered for the first time that light can twist metal to control chirality of nanostructures (hereafter, chiral nanoneedles). The helicity optical vortices is transferred constituent elements irradiated material (mostly melted material), resulting in formation nanoneedles. these nanoneedles could be controlled by just changing sign vortex. tip curvature was measured <40 nm, which less than 1/25th laser wavelength (1064 nm). Such will enable us selectively distinguish and activity...

We discovered that chiral nanoneedles fabricated by vortex laser ablation can be used to visualize the helicity of an optical vortex. The orbital angular momentum light determines chirality nanoneedles, since it is transferred from metal. Only spin reinforce helical structure created nanoneedles. also found vortices with same total (defined as sum and momenta) are degenerate, they generate spiral frequency.

Microneedle fabrication on a metal surface based laser ablation using twisted light with spin was demonstrated, for the first time.The resulting needle showed height of at least 10 µm above target and tip diameter less than 0.3 µm.We also demonstrated two-dimensional 5 × 6 microneedle array.The needles were uniformly well shaped an average length about 0.5 µm, respectively.

We have discovered that a novel chiral structured surface relief (termed 'conch'-shaped relief) with height of over 1 μm can be formed in an azo-polymer film merely by employing circularly polarized optical vortex irradiation total angular momentum j = ±2. The temporal evolution the conch-shaped was also observed. results provide physical insight into how light is transferred to material through mass transport cis-trans photo-isomerization. Such reliefs chirality, which functional chemical...

Abstract Recent work has shown that irradiation with light possessing orbital angular momentum (OAM) and an associated phase singularity, is optical vortex, twists a variety of materials. These include silicon, azo‐polymer, even liquid‐phase resins to form various helically structured This article provides review the unique helical‐structured materials created novel fundamental phenomena enabled by this interaction between both spin OAM matter. Such light‐induced will potentially lead...

Abstract The formation of a monocrystalline silicon needle by picosecond optical vortex pulse illumination was demonstrated for the first time in this study. dynamics further revealed employing an ultrahigh-speed camera. melted collected through deposition to dark core vortex, forming on submicrosecond scale. composed with same lattice index (100) as that substrate and had height approximately 14 μm thickness 3 μm. Overlaid pulses allowed be shaped 40 without any changes crystalline...

The unique properties of optical vortex beams, in particular their spiral wavefront, have resulted the emergence a wide range applications for this type laser output. These include tweezing, free space communications, microfabrication, environmental optics, and astrophysics. However, much like its infancy, adaptation output requires diversity wavelengths. We report on recent progress development sources particular, focus wavelength extension, where nonlinear processes been used to generate...

Skyrmions, topologically stable configurations of a three-component vector field with sophisticated textures, have been considered in many contexts, including atomic physics, Bose–Einstein condensates, liquid crystals, and magnetic materials. Although optical counterparts skyrmions extensively studied theoretically recently demonstrated the laboratory experiments, their experimental mapping is challenging due to fine, three-dimensional, complicated structure polarization distributions. Here,...

A terahertz (THz) spiral phase plate with high transmission (&amp;gt;90% after Fresnel correction) and low dispersion has been developed based on the Tsurupica olefin polymer. Direct observations of topological charge (both magnitude sign) a THz vortex beam are performed by using camera tilted lens focusing radial defect introduction. The outputs ±1 (or ±2) obtained at frequency 2 4) THz.

It was discovered that optical vortices twist isotropic and homogenous materials, e.g., azo-polymer films to form spiral structures on a nano- or micro-scale. However, the formation mechanism has not yet been established theoretically. To understand of surface relief in film, we theoretically investigate radiation force induced an homogeneous material under irradiation using continuous-wave vortex with arbitrary topological charge polarization. is revealed requires positive (negative) spin...

The exact power output of a table-top-sized terahertz (THz)-wave source using nonlinear optical process has not been clarified because detectors for these experiments [Si bolometer, deuterated triglycine sulfate (DTGS), etc.] are calibrated well. On the other hand, powermeters mid-infrared (mid-IR) region well established and calibrated. We constructed high-power dual-wavelength parametric oscillator with two KTP crystals as light difference frequency generation. obtained powers dual waves...

We demonstrate the direct generation of visible vortex beams at 640 nm and 607 by employing an off-axis pumping scheme in a diode end-pumped Pr3+:YLF laser. A detailed numerical analysis, based on coherent superposition Hermite-Gaussian modes with different amplitudes phases, is perfectly consistent experimentally observed lasing modes. The maximum output powers have been measured to be 808 mW 211 pump power 3.16 W, for wavelengths nm, respectively. also handedness control generated beam....

Multicolor visible high-order Bessel (Bessel-vortex) beams which have a helical wavefront and long confocal length garnered significant interest for applications in materials processing biomedical technologies. In this paper, we demonstrate the direct generation of multicolor (523, 605 637 nm) Bessel-vortex from Pr 3+ -doped water-proof fluoro-aluminate glass (Pr : WPFG) fiber laser with an intracavity lens induces chromatic spherical aberration. The handedness generated beam is selectively...

Widely tunable terahertz (THz)-wave generation using difference frequency (DFG) in an organic N-benzyl-2-methyl-4-nitroaniline (BNA) crystal was demonstrated. To our knowledge, this is the first report of THz-wave by BNA DFG. Large, high-quality single crystals (ϕ 8 mm×30 mm) were grown vertical Bridgman method. The nonlinear optical (NLO) coefficient d33 ~234 pm/V, which largest value reported for any yellow NLO material. collinear phase-matching condition type-0 configuration satisfied a...

An effective and widely tunable means of producing terahertz (THz) radiation using difference-frequency generation (DFG) in an organic N-benzyl-2-methyl-4-nitroaniline (BNA) crystal was demonstrated by optimizing the pump wavelengths. We calculated (wideband) refractive index coherence length mapping BNA to establish optimum phase-matching condition DFG configuration. To satisfy conditions over range 0.1-20 THz, both wavelengths were varied from 780 950 nm, optical wavelength dependency...

The first demonstration of a mid-infrared optical parametric oscillator pumped by 1-μm vortex pulses is presented. A 0.5-mJ 2-μm fractional pulse having half-integer topological charge generated. Using this system, 0.24-mJ with 1 can be created. charges the are observed an interferometric technique in combination second-harmonic frequency conversion.

We generated tunable 2-μm optical vortex pulses with a topological charge of 1 or 2 in the wavelength range 1.953-2.158 μm by realizing anisotropic transfer from pump beam to signal output vortex-pumped half-symmetric parametric oscillator. A maximum energy 2.1 mJ was obtained at 22.8 mJ, which corresponds slope efficiency 15%. The charges and idler were investigated using shearing interferometric technique employing low-spatial-frequency transmission grating.

A helical surface relief can be created in an azo-polymer film simply by illuminating circularly polarized light with spin angular momentum and without any orbital momentum. The helicity of the is determined sign illumination induces motion to shape as intermediate form; a subsequent transformation non-helical bump-shaped central peak creates final form additional exposure time. mechanism for formation such was also theoretically analyzed using formula optical radiation force homogeneous...

We demonstrate the generation of high-quality tunable terahertz (THz) vortices in an eigenmode by employing soft-aperture difference frequency vortex and Gaussian modes. The generated THz output exhibits a orbital angular momentum (OAM) mode with topological charge ℓTHz = ±1 range 2-6 THz. maximum average power obtained was ∼3.3 µW at 4

Photopolymerization is a powerful technique to create arbitrary micro-objects with high spatial resolution. Importantly, date all photopolymerization studies have been performed incident light fields planar wavefronts and solely exploited the intensity profile of beam. We investigate possessing orbital angular momentum, characterized by topological charge l. show both experimentally theoretically that, as consequence nonlinear self-focusing optical field, creates an annular-shaped...

Abstract Optical vortex, possessing an annular intensity profile and orbital angular momentum (characterized by integer termed a topological charge) associated with helical wavefront, has attracted great attention for diverse applications due to its unique properties. In particular terahertz (THz) frequency range, several approaches THz vortex generation, including molded phase plates consisting of metal slit antennas, achromatic polarization elements binary-diffractive optical elements,...

We report a simple single-pixel imaging system with low mean squared error in the entire terahertz frequency region (3-13 THz) that employs thin metallic ring series of directly perforated random masks and subpixel mask digitization technique. This produces high pixel resolution reconstructed images, up to 1200 x pixels, area 32 mm mm. It can be extended develop advanced systems near-ultraviolet region.