Scanning Mirror System Research Articles

Cross-sectional characteristics of visible emission spectra in partially premixed flames

Visible spectral characteristics of cross-sectional emissions from a partially premixed methane/air flame and a propane/air flame have been investigated. An optical train with a two-axis scanning mirror system was used to record line-of-sight emission spectra from 354nm to 618nm, and inversion technique was applied to obtain cross-sectional emission spectra. By analyzing the reconstructed emission spectra, cross-sectional intensities of CH and C 2 radicals were separated from the background emission. The blue flame edge and yellow flame edge were also obtained by image processing technique for edge detection with color photographs of the flames. These edges were compared with radial distributions of CH, C 2 radicals and background emission. The CH radicals were observed at the blue flame edge. The background emission was generated by soot precursors at upstream of the flame and by soot at downstream of the flame. The C 2 radicals in the propane/air flame were more noticeable than those in the methane/air flame.

Programmable spatial filtering with bacteriorhodopsin

We describe a programmable spatial-filtering system using bacteriorhodopsin (BR) film as a programmable, optically addressed spatial light modulator illuminated by a single wavelength of light. We use a computer-controlled mirror scanning system to write time-varying filter functions to the BR film and present proof-of-principle experimental results that demonstrate several elementary filtering operations.

Laser beam scanning by rotary mirrors I Modeling mirror-scanning devices

Avector approach to tracing the path of a laser beam through an optical system containing movable plane mirrors is described, which permits a unified treatment of a number of basic mirror-scanning devices. We show that the scan field produced by the mirror-scanning system is a curved surface with a straight line as its generating element. The cross section of the scan field can be a circle, an ellipse, or a curve in the shape of an egg. Based on this understanding, some advanced topics are addressed, e.g., the relationship between the scan field and the scan pattern, the dependence of the scan pattern on the location and orientation of the observation surface, optical distortions in a scan pattern, spot-size enlargement caused by non-normal incidence of the scan beam on the observation plane, and so on. Design equations and curves are derived for the mirror-scanning devices that most frequently exist in linear and circular scan technology. Part II contains an analysis of the galvanometer-based optical scanner paddle scanner and the regular polygon. In Part III, X-Y scanning systems are studied.

Determination of poloidal variation of the electron temperature and density in a tokamak plasma using VUV spectroscopy

An ergodic magnetic limiter (EML) creates a randomization of the magnetic field at the edge of a tokamak plasma. As a result, poloidal changes in the electron temperature and density profiles are expected. We describe an experiment in which these parameters have been measured during EML experiments on the TEXT tokamak using line ratios emitted in the VUV by intrinsic oxygen and carbon charge states isoelectronic with Be I. The spectra were recorded by means of two photometrically calibrated spectrometers equipped with time-resolving, multispectral image intensifier detectors. A scanning mirror system mounted close to the plasma at grazing incidence, enable the tangential view of the tokamak edge plasma. The reliability of the line ratio used as local density and temperature diagnostics is discussed also.

Impurity flux measurements during ICRF heating in ASDEX

During ICRF heating in ASDEX a significant increase of the central radiation due to enhanced radiation from iron is usually observed. To investigate and localize impurity fluxes from the walls, antennas and built in structures we used a new scanning mirror system in connection with our visible spectroscopy diagnostics. During modulated ICRF heating we measured impurity fluxes in the vicinity of the ICRF-SE antenna. Our measurements show a large enhancement of metallic impurity fluxes with ICRF as a result of increased sputtering yields.

Laser Spot Distortion in the Spherical Mirror Scanning System

Laser Spot Distortion in the Spherical Mirror Scanning System

Wide Field Specular Microscopy: Clinical and Research Applications

Through the use of a scanning mirror system, the field of view has been expanded to as much as 0.9 mm in diameter. Both contact and non-contact specular microscopy are possible, each having advantages. In a research application, wound healing in rabbit endothelium is documented by time lapse photography. The study demonstrates the capability to return to an area of interest provided there is a landmark. Clinical applications and advantages over conventional specular microscopy are discussed.

High-Quality Laser Color Television Display

Special features of a new 523-line scanned laser display system are described. These include: (1) the addition of beam wobbling to the polygonal mirror scanning system to allow improvement of the horizontal resolution by a factor of 3.6; (2) a relay lens between the horizontal and vertical deflectors, to minimize deflector aperture requirements; (3) an auxiliary deflection system to compensate for raster irregularity; and (4) an automatic optical black-level control system. The resulting horizontal and vertical resolutions are 500 and 370 TV lines, respectively, and raster uniformity is excellent. Horizontal jitter is less than 0.02 μs and vertical jitter is unnoticeable. The primary colors used and their sources are: 632.8 nm (He–Ne laser), 514.5 nm (argon ion laser) and 476.5 nm (argon ion laser). Low screen brightness is the biggest remaining problem.