Cyanines during the 1990s: A Review

We studied the photoelectrochemical properties of nanoporous TiO2 electrodes sensitized by a series of benzothiazole merocyanine dyes, 3-carboxyalkyl-5-[2-(3-alkyl-2-benzothiazolinyldene) ethylidene]-2-thioxo-4-thiazolidinone, having a different alkyl chain length. Broadening of absorption spectra and a large red shift of the absorption threshold up to 680 nm were observed by adsorbing dyes on a porous TiO2 electrode, suggesting the formation of various kinds of J aggregates of the dye on the TiO2 surface. The dye was fixed by a chelate-like linkage of the carboxylate anchoring group on the TiO2 surface, rather than by an ester linkage. The solar light-to-power conversion efficiency (ηsun) and the incident photon-to-current conversion efficiency (IPCE) increased with increasing the length of alkyl chain attached to the benzothiazole ring. The maximum ηsun value was 4.5%, which is the second highest value among organic dye systems reported so far (AM-1.5, 100 mW/cm2). The J aggregates of the dyes having lo...

Photoelectrochemical Properties of J Aggregates of Benzothiazole Merocyanine Dyes on a Nanostructured TiO2 Film

An optical code symbol reading system includes a housing having a light transmission aperture, and at least one sound port formed in the housing. The system includes an optical code symbol reading subsystem for optically reading a code symbol in the field external to the light transmission aperture, and generating symbol character data representative of the read code symbol. An electro-acoustic transducer is disposed in the housing for producing sonic energy. Also, an acoustic-waveguide structure is disposed in the housing, for coupling the sonic energy produced from the electro-acoustic transducer, to the at least sound wave port formed the housing, to audibly signal the reading of a code symbol to the operator of the optical code symbol reading system.

Code symbol reading system

Efficient sensitization of nanocrystalline TiO2 films with cyanine and merocyanine organic dyes

An image capture and processing system supports a multi-tier modular software, and plug-in extendable, architecture. The image capture and processing system can be realized as an image-capturing cell phone, a digital camera, a video camera, mobile computing terminal and portable data terminal (PDT), provided with suitable hardware platform, communication protocols and user interfaces. A third-party customer can write and install a software plug-in into the application layer so as to enhance or modify the behavior of the image capture and processing system without any required knowledge of the hardware platform, communication protocols and/or user interfaces.

Image capture and processing system supporting a multi-tier modular software architecture

A waveguide type reduction type image sensor has a waveguide type light source having a light emitting element (6) and a substrate (5) including optical waveguides having a planar waveguide and a tapered waveguide. The waveguide type reduction type image sensor also has a light detecting section having a microlens array (4), an optical waveguide substrate (2) and a CCD array (3). The microlens array (4) converges reflected light from an original (1) onto an incident face of the optical waveguide substrate (2). The optical waveguide substrate (2) has L-shaped optical waveguides for guiding the converged light to the CCD array (3) located on a substrate face perpendicular to the incident face. The CCD array (3) converts the guided light to an electric signal and outputs this electric signal. A manufacturing method of this waveguide type reduction type image sensor is also shown.

Waveguide type compact optical scanner and manufacturing method thereof

A color image sensor has a white fluorescent tube as a light source, a microlens array with three rows of microlenses arranged vertically, a three-layer optical waveguide array and a three-line color CCD with color filters. The waveguides in each waveguide array layer are bent so that the interval between successive waveguides becomes narrower from the input end toward the output end. The three-line color CCD has three lines of light-receiving elements (photodiodes) as the light sensing portion. These lines in the light-receiving element array are arranged vertically at the same intervals as the waveguide layers are arranged. Further, a cylindrical lens is attached to cover the microlens array. Because of the presence of this cylindrical lens, the images of light beams incident on different microlenses of the microlens array corresponding to different waveguide layers are the same image from an identical area on the original.

Color image sensor and a production method of an optical waveguide array for use therein

Three types of aggregates of spiropyran with long and short hydrophobic alkyl chains

The formation of J-aggregates in Langmuir monolayers of a neat merocyanine dye (3-carboxymethyl-5-[2-(3-octadecyl-2-benzothiazolinyldene)ethylidene]-2-thioxo-4-thiazolidinone) has been examined by measuring the normal incidence absorption spectra. Five types of J-aggregates were found to be formed, depending on the temperature and the concentration and type of cations present in the subphase. The shift in the absorption peak wavelength on the J-aggregates formation is accounted for in terms of the number and the geometrical arrangement of the chromophores in each J-aggregate. The spectral shifts were analyzed numerically using both a point dipole model and a transition density model. These calculations indicate that the five different J-aggregates are linear ones with aggregation numbers ranging from 2 to 6.

David Heard

Papers

Waveguide type compact optical scanner and manufacturing method thereof

Color image sensor and a production method of an optical waveguide array for use therein

Three types of aggregates of spiropyran with long and short hydrophobic alkyl chains

Five Types of J-Aggregates in Single-Chain Merocyanine Langmuir Monolayers on an Aqueous Subphase

Waveguide type compact optical scanner