Using Diffractive Optical Elements

Abstract

A diffractive optical element (DOE) uses thin micro‐structure patterns to alter the phase of the light that is propagated through it. Those micro‐structures, once properly designed, can manipulate the light to almost any desired intensity profile or shape. This technology enables many functions and light manipulations which are not feasible with standard refractive optics.

Random Silica-Glass Microlens Arrays Based on the Molding Technology of Photocurable Nanocomposites

“…In recent years, high-energy lasers have attracted much attention for their wide range of applications in laser illumination, − laser detection, etc. − Lasers exhibit a Gaussian distribution and strong coherence, requiring beam modulation for applications in photolithography, − laser projection, high-performance illumination, etc. − The realization of high-energy laser beam modulation often relies on extremely high threshold materials, which are conventionally used by silica glass. Among a bunch of approaches to beam homogenization, − microlens arrays (MLAs), due to their superior energy utilization, high flexible integration, and high homogeneity, are one of the most commonly used homogenizers. − However, due to the periodicity of the MLAs, interference between beamlets happens, and their related interference fringes appear in the obtained homogenized spots, seriously impacting the uniformity of the spots. To break the coherence between small beams, a continuous profile MLA with random aperture size and arrangement of sub-lenses is proposed, which is generally called random microlens arrays (rMLAs).…”

3D Switchable Diffractive Optical Elements Fabricated with Two‐Photon Polymerization

“…[ 1 ] Applications of DOEs span across a vast number of industries and include holographic displays, augmented reality (AR)/virtual reality (VR), spectroscopy, aberration correction, beam steering, beam shaping, and 3D depth sensing. [ 2–16 ]…”

“…[1] Applications of DOEs span across a vast number of industries and include holographic displays, augmented reality (AR)/virtual reality (VR), spectroscopy, aberration correction, beam steering, beam shaping, and 3D depth sensing. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] write a DOE into a photoresist with a beam diameter of around 7 μm. A nematic LC was then placed on top of the DOE that was encoded into the photoresist.…”

Spiral-Phase-Defect Resonator and Its Application in Vortex Laser of Controllable Topological Charges

“…This demand for easy access to lasers carrying OAMs is increasing, which accelerates the development of vortex laser technologies. Passive mode conversion techniques, such as diffractive optics [10], spatial light modulators [11,12], and engineered anisotropic materials [13], are mature and have very high conversion efficiencies of more than 90% [14]. Their limited working range, less desirable beam quality, and OAM purity limit the usefulness of structured light in long-range OAM multiplexing communications [15].…”