Optical tweezers use the forces exerted by a strongly focused beam of light to trap and move objects ranging in size from tens of nanometres to tens of micrometres. Since their introduction in 1986, the optical tweezer has become an important tool for research in the fields of biology, physical chemistry and soft condensed matter physics. Recent advances promise to take optical tweezers out of the laboratory and into the mainstream of manufacturing and diagnostics; they may even become consumer products. The next generation of single-beam optical traps offers revolutionary new opportunities for fundamental and applied research.

http://physics.nyu.edu/grierlab/nreview2c/nreview2c.pdf

A revolution in optical manipulation

A laser cavity formed from a single defect in a two-dimensional photonic crystal is demonstrated. The optical microcavity consists of a half wavelength–thick waveguide for vertical confinement and a two-dimensional photonic crystal mirror for lateral localization. A defect in the photonic crystal is introduced to trap photons inside a volume of 2.5 cubic half-wavelengths, approximately 0.03 cubic micrometers. The laser is fabricated in the indium gallium arsenic phosphide material system, and optical gain is provided by strained quantum wells designed for a peak emission wavelength of 1.55 micrometers at room temperature. Pulsed lasing action has been observed at a wavelength of 1.5 micrometers from optically pumped devices with a substrate temperature of 143 kelvin.

https://science.sciencemag.org/content/sci/284/5421/1819.full.pdf

Two-Dimensional Photonic Band-Gap Defect Mode Laser

Nano-optics of surface plasmon polaritons

This article presents an overview of current research activities that center on monodispersed colloidal spheres whose diameter falls anywhere in the range of 10 nm to 1 μm. It is organized into three parts: The first part briefly discusses several useful methods that have been developed for producing monodispersed colloidal spheres with tightly controlled sizes and well-defined properties (both surface and bulk). The second part surveys some techniques that have been demonstrated for organizing these colloidal spheres into two- and three-dimensionally ordered lattices. The third part highlights a number of unique applications of these crystalline assemblies, such as their uses as photonic bandgap (PBG) crystals; as removable templates to fabricate macroporous materials with highly ordered and three-dimensionally interconnected porous structures; as physical masks in lithographic patterning; and as diffractive elements to fabricate new types of optical sensors. Finally, we conclude with some personal perspectives on the directions towards which future research in this area might be directed.

Monodispersed Colloidal Spheres: Old Materials with New Applications

Two-photon excitation provides a means of activating chemical or physical processes with high spatial resolution in three dimensions and has made possible the development of three-dimensional fluorescence imaging, optical data storage, and lithographic microfabrication. These applications take advantage of the fact that the two-photon absorption probability depends quadratically on intensity, so under tight-focusing conditions, the absorption is confined at the focus to a volume of order λ3 (where λ is the laser wavelength). Any subsequent process, such as fluorescence or a photoinduced chemical reaction, is also localized in this small volume. Although three-dimensional data storage and microfabrication have been illustrated using two-photon-initiated polymerization of resins incorporating conventional ultraviolet-absorbing initiators, such photopolymer systems exhibit low photosensitivity as the initiators have small two-photon absorption cross-sections (δ). Consequently, this approach requires high laser power, and its widespread use remains impractical. Here we report on a class of π;-conjugated compounds that exhibit large δ (as high as 1, 250 × 10−50 cm4 s per photon) and enhanced two-photon sensitivity relative to ultraviolet initiators. Two-photon excitable resins based on these new initiators have been developed and used to demonstrate a scheme for three-dimensional data storage which permits fluorescent and refractive read-out, and the fabrication of three-dimensional micro-optical and micromechanical structures, including photonic-bandgap-type structures.

Two-photon polymerization initiators for three-dimensional optical data storage and microfabrication

The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

http://ieeexplore.ieee.org/iel5/6354/16969/00781867.pdf

Photonic crystals

Optical Wireless Communications international standards — A review

Stop-band optical filters protecting from harmful infrared radiation: wavelength-scale electromagnetic modelling by the method of single expression

Advantages of optical links for data transmission are doubtless. Different types of optical interconnects for inter/intra chip links are under development. Electro-optical modulators (EOMs) are one of key elements of optical links. Transmission-type EOM for chip-to-chip optical interconnection is analysed by the method of single expression. Transmission properties of Fabry-Perot resonant type modulator consisting of electro-optical material embedded between Si/SiO2 distributed Bragg reflectors (DBRs) are analysed. From four possible types of DBRs the suitable structure has been chosen. Two semitransparent conducting electrodes for applying electrical signal to electro-optical material are parts of the nano-layered structure and are included in the electromagnetic model. As an external light source, a conventional laser diode of wavelength 1.55 $\mu m$ is taken. Efficiency of optical wave intensity modulation is analysed by means of influence of electro-optical material's permittivity change (under applied voltage) on resonator's maximal transmission peak shift. For the electro-optical material LiNbO3 of thickness about 1 mm the suitable resonance peak shift is obtained.

Transmission Type Nano-Layered Electro-Optical Modulator for Chip-to-Chip Optical Interconnection: Electromagnetic Modelling by the Method of Single Expression

M. Marciniak

Papers

Photonic crystals

Optical Wireless Communications international standards — A review

Stop-band optical filters protecting from harmful infrared radiation: wavelength-scale electromagnetic modelling by the method of single expression

Transmission Type Nano-Layered Electro-Optical Modulator for Chip-to-Chip Optical Interconnection: Electromagnetic Modelling by the Method of Single Expression