Recently, there has been an explosion of interest in metalenses for imaging. The is primarily based on their subwavelength thicknesses. Diffractive gratings have used as thin optical elements since the late 19th century. Here, we show that multilevel diffractive lenses (MDLs), when designed properly, can exceed performance metalenses. Furthermore, MDLs be and fabricated with larger constituent features, making them accessible to low-cost, large-area volume manufacturing, which generally...

Abstract We exploit the inherent dispersion in diffractive optics to demonstrate planar chromatic-aberration-corrected lenses. Specifically, we designed, fabricated and characterized cylindrical lenses that efficiently focus entire visible band (450 nm 700 nm) onto a single line. These devices are essentially pixelated, multi-level microstructures. Experiments confirm an average optical efficiency of 25% for three-wavelength apochromatic lens whose chromatic shift is only 1.3 μm 25 lateral...

In the past, formation of microscale patterns in far field by light has been diffractively limited resolution to roughly half wavelength radiation used. Here, we demonstrate lines with an average width 36 nanometers (nm), about one-tenth illuminating lambda1 = 325 nm, made applying a film thermally stable photochromic molecules above photoresist. Simultaneous irradiation second wavelength, lambda2 633 renders opaque writing beam except at nodal sites, which let through spatially constrained...

We demonstrate imaging over the visible band using a single planar diffractive lens. This is enabled via multi-level optics that designed to focus broad wavelength range, which we refer as an achromatic lens (ADL). designed, fabricated and characterized two ADLs with numerical apertures of 0.05 0.18. Diffraction-limited focusing demonstrated for NA = measured efficiency 40% across entire spectrum (450 nm 750 nm). lenses monochromatic color CMOS sensor, video under natural sunlight other...

We present an extension of the direct-binary-search algorithm for designing high-efficiency multi-wavelength diffractive optics that reconstruct in Fresnel domain. A fast computation method solving optimization problem is proposed. Examples three-wavelength with over 90% diffraction efficiency are presented. These optical elements three distinct image patterns when probed using design wavelengths. Detailed parametric and sensitivity studies conducted, which provide insight into optic's...

A lens performs an approximately one-to-one mapping from the object to image plane. This in plane is maintained within a depth of field (or referred as focus, if at infinity). necessitates refocusing when images are separated by distances larger than field. Such mechanisms can increase cost, complexity, and weight imaging systems. Here we show that judicious design multi-level diffractive (MDL) it possible drastically enhance focus over 4 orders magnitude. Using such lens, able maintain for...

Conventional polarizers operate by rejecting undesired polarization, which limits their transmission efficiency to much less than 50% when illuminated unpolarized light. We designed, fabricated, and characterized a multilevel metamaterial linear polarizer that rotates light with polarization perpendicular its principal axis 90 deg. Light parallel is transmitted undisturbed. Thereby, such able output linearly polarized from input substantially higher the theoretical upper limit of 50%. A...

Significance We demonstrate, with simulations corroborated by experiments, that broadband long-wave infrared (LWIR) imaging is possible a single flat lens thickness of 10 μm and weight over 100 times less than conventional refractive optics. Reducing the LWIR optics crucial for increasing range camera-carrying drones as well reducing head neck injuries among camera-borne soldiers. The technology discussed herein will be extremely useful not only to specialists but also camera designers users...

Flat lenses enable thinner, lighter, and simpler imaging systems. However, large-area high-NA flat have been elusive due to computational fabrication challenges. Here we applied inverse design create a multi-level diffractive lens (MDL) with thickness <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mo>&lt;</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>1</mml:mn> </mml:mrow> <mml:mo>.</mml:mo> <mml:mn>35</mml:mn> <mml:mspace width="thickmathspace"/>...

The increasingly important role of maskless lithography in industry, research, and emerging applications nanoscale science engineering is discussed. various forms are reviewed with major emphasis on zone-plate-array lithography, a new paradigm that promises low cost extendibility to the limits lithographic process.

We describe a simple, compact, low-cost spectrometer comprised of broadband diffractive optic and sensor array. The is designed to disperse incident collimated light onto the array in prescribed manner defined by its spatial-spectral point-spread function. By applying novel nonlinear optimization method, we show that it possible reconstruct unknown spectrum from measured image on experimentally reconstructed numerous spectra with resolution as small ~1 nm bandwidths large 450 nm....

Polarization controlling devices such as polarization splitters and rotators are critical elements in integrated-photonic circuits that function via polarization-diversity schemes. Here, we present the design of an ultra-compact nanophotonic-polarization rotator (NPR) rotates state from TE to TM with a simulated extinction ratio 23dB over coupling length 5µm operating bandwidth 40nm. This all-silicon device can be fabricated single lithography step have characterized preliminary exhibiting...

Abstract Photonic-integrated devices need to be adequately spaced apart prevent signal cross-talk. This fundamentally limits their packing density. Here we report the use of nanophotonic cloaking render neighbouring invisible one another, which allows them placed closer together than is otherwise feasible. Specifically, experimentally demonstrated waveguides that are by a distance ∼ λ 0 /2 and designed with centre-to-centre spacing as small 600 nm (&lt; /2.5). Our experiments show...

We applied nonlinear optimization to design nanophotonics-based metamaterials for efficient free-space-to-waveguide coupling. Three devices were designed, fabricated and characterized. The first device couples incident light into a multi-mode waveguide, the second single-mode waveguide directly, third separates two orthogonal polarizations waveguides. All offer comparable or higher coupling efficiencies, are easier fabricate, demonstrate bandwidth when compared conventional devices....

We present the first lithography results that use high-numerical-aperture photon sieves as focusing elements in a scanning-optical-beam-lithography system [J. Vac. Sci. Technol. B 21, 2810 (2003)]. Photon are novel optical offer advantages of higher resolution and improved image contrast compared with traditional diffractive optics such zone plates [Nature 414, 184 (2001)]. fabricated highest-numerical-aperture reported to date experimentally verified their characteristics. propose two new...

Conventional color imaging requires absorptive color-filter arrays, which exhibit low light transmission. Here, we replace the array with a transparent diffractive-filter (DFA) and apply computational optics techniques to enable sensitivity that is enhanced by factor as high 3.12. The DFA diffracts incident onto conventional monochrome sensor create intensity distributions are wavelength dependent. By first calibrating these wavelength-dependent then applying techniques, demonstrate...

In this Letter, we report the preliminary demonstration of a new paradigm for photovoltaic power generation that utilizes broadband diffractive-optical element (BDOE) to efficiently separate sunlight into laterally spaced spectral bands. These bands are then absorbed by single-junction cells, whose band gaps correspond incident We designed such BDOEs utilizing modified version direct-binary-search algorithm. Gray scale lithography was used fabricate these multilevel optics. They were...

We applied nonlinear optimization to design integrated digital metamaterials in silicon for unidirectional energy flow. Two devices, one each polarization state, were designed, fabricated, and characterized. Both devices offer comparable or higher transmission efficiencies extinction ratios, are easier fabricate, exhibit larger bandwidths more tolerant fabrication errors, when compared alternatives. Furthermore, device footprint is only 3μm × 3μm, which the smallest optical diode ever...

A coating that embodies omnidirectional optical properties over a wide range of wavelengths and possessing specific wetting capabilities is established on glass platforms.

Space-time wave packets are a class of pulsed optical beams that diffraction-free and dispersion-free in free space by virtue introducing tight correlation between the spatial temporal degrees freedom field. Such have been recently synthesized novel configuration makes use light modulator to realize required spatio-temporal correlations. This arrangement combines pulse-modulation beam-shaping assign one frequency each wavelength according prescribed function. Relying on results several...

The propagation distance of a pulsed beam in free space is ultimately limited by diffraction and space-time coupling. "Space-time" (ST) wave packets are beams endowed with tight spatio-temporal spectral correlations that render them propagation-invariant. Here we explore the limits for ST packets. Making use specially designed phase plate inscribed gray-scale lithography having laser-damage threshold ∼0.5 J/cm2, synthesize light sheet width ≈700 μm bandwidth ∼20 nm, confirm ≈70 m.

We experimentally demonstrate a ∼1-mm-thick near infrared camera comprised of multi-level diffractive lens coupled with conventional monochrome image sensor. performed careful measurements the point-spread function, modulation transfer focusing efficiency, aberrations, and field view camera.

It is generally assumed that correcting chromatic aberrations in imaging requires optical elements. Here, we show by allowing the phase image plane to be a free parameter, it possible correct variation of focal length over an extremely large bandwidth, from visible (Vis) longwave infrared (LWIR) wavelengths using single diffractive surface, i.e., flat lens. Specifically, designed, fabricated and characterized flat, multi-level lens (MDL) with thickness {\pounds} 10{\mu}m, diameter ~1mm, =...