The first known demonstration of tunable terahertz-wave generation by difference-frequency generation of dual signal-wave quasi-phase-matched optical parametric oscillation was performed with periodically poled LiNbO(3) (PPLN) with a series of gratings. An organic ionic salt, 4-dimethylamino-N-methyl-4-stilbazolium-tosylate (DAST), was used as a nonlinear crystal. A compact terahertz-wave sourc...

Histologic study of lesions produced by krypton red (647.1 nm) and krypton yellow (568.2 nm) laser lights reported here suggests advantages in alternating these two wavelengths in photocoagulation. Selection of the best wavelength to be used in a given location on the retina should result from pre-determined absorbance conditions in that location. The feasibility of the relative measurement of ...

We experimentally demonstrate an all-diffractive optical setup for digital lensless holographic microscopy with easy wavelength line selection and micrometric resolution. In the proposed system, an ultrashort laser pulse is focused with a diffractive lens (DL) onto a pinhole of diameter close to its central wavelength to achieve a highly spatially coherent illumination cone as well as a spectra...

A new laboratory apparatus devoted to the characterization of various devices for the X-UV range (100-5000 eV), such as mirrors, diffraction gratings, spectrometers or detectors is described. The apparatus includes open x-ray tubes as x-ray sources, a two-crystal monochromator for wavelength selection and a goniometer. Various examples of its use are presented : dispersive mode where the radiat...

II Electro-optic devices permit rapid wavelength selection and high-bandwidth frequency modulation in single-frequency solid state lasers. Laser dynamics limits both the speed ofwavelength selection and the linearity offrequency modulation. The maximum speed of laser mode selection is determined by the buildup ofoscillation from spontaneous emission. For frequency modulation, the minimum fracti...

In optical WDM networks, transmission of information along optical lines is advantageous since it has high transmission capacity, scalability, feasibility and also high reliability. But large amount of information is being carried; any problem during transmission can lead to severe damage to the data being carried. Hence it is essential to consider the routing as well as the wavelength assignme...

In optical WDM networks, transmission of information along optical lines is advantageous since it has high transmission capacity, scalability, feasibility and also high reliability. But large amount of information is being carried; any problem during transmission can lead to severe damage to the data being carried. Hence it is essential to consider the routing as well as the wavelength assignme...

This paper addresses alternative procedures to the ESO supplied pipeline procedures for the reduction of UVES spectra of two quasar spectra to determine the value of the fundamental constant μ = Mp/Me at early times in the universe. The procedures utilize intermediate product images and spectra produced by the pipeline with alternative wavelength calibration and spectrum addition methods. Spect...

Classification is broadly used in a range of exploration technologies. This paper will summarize standard classification methods and provide a new hybrid method for classifying spectra used in mapping mineralogy with hyperspectral remote sensing data. Classification methods commonly employed do not allow the user specifically to identify key features that give confidence as to the quality of th...

In this paper, we propose and demonstrate a technique to realize multiwavelength operation in erbium-doped fiber lasers (EDFLs) by inserting two Fabry Pérot laser diodes (FP-LDs) in the laser cavity respectively in cascaded and parallel way. The FP-LDs not only act as wavelength selection elements, but also offer optical gain or loss for the operation wavelengths in the laser cavity. The gains ...