Recently the importance of measuring in vivo action spectra for photodynamic therapy (PDT) with various photosensitizers was pointed out in this journal [1]. It was shown that the effect of PDT with zinc phthalocyanine tetrasulphonic acid (ZnPcS4) increases considerably when the wavelength of the activating light is increased from 680 to 692 nm. In this regard a further comparison with haematop...

To study laser tissue interaction absorption and backscattering are the key factors to find the changes in structure and dynamics of turbid media such as complex fluids and biological tissues. Here a method to select suitable wavelength for maximum interaction with a particular type of tissue/tissue phantom, and study of backscattered light intensity at chosen wavelength with respect to change ...

A low cost LED based spectrometer is described. This LED based spectrometer could be operated as a standalone instrument or under PC control via serial link. A total of seven wavelength selections are available by the plug-and-measure LED light module. With the seven wavelength selections, the LED based spectrometer could provide qualitative visible absorption spectra that predict the absorptio...

We report the measurement of optically rectified terahertz (THz) wave power relative to the optical excitation area. Rectified THz wave power reaches its maximum when radius r of the optical excitation area is comparable to the center wavelength of the rectified THz radiation. When r is smaller than the center wavelength of the rectified THz radiation, an r(2) relationship is demonstrated. A mo...

We propose a new wavelength assignment scheme that improves the blocking probability of WDM networks that use limited-range wavelength converters. Limited-range wavelength converters are attractive for wavelength-routed networks, given current technology, since they offer good utilization of the wavelength resource and improved blocking probability. However, their conversion ranges are limited;...

Introduction: Ultraviolet index (UVI) is a dimensionless scale, which describes the maximum intensity and biologic effects of UV during a specific time, on surface of the earth. The UVI is  an  international  standard measurement of  the  strength  of sunburn  producing ultraviolet radiation at a particular place and time. This index is an easy and understandable concept for pr...

In optical networks with wavelength division multiplexing (WDM), multiple connections can share a link if they are transmitted on different wavelengths. We study the problem of satisfying a maximum number of connection requests in a directed tree network if only a limited number W of wavelengths are available. In optical networks without wavelength converters this is the maximum path coloring (...

The use of dye-sensitized solar cells (DSSCs) is widespread owing to their high power conversion efficiency (PCE) and low cost of manufacturing. We prepared multi-shaped Ag nanoparticles (NPs) and introduced them into DSSCs to further enhance their PCE. The maximum absorption wavelength of the multi-shaped Ag NPs is 420 nm, including the shoulder with a full width at half maximum (FWHM) of 121 ...

In addition to the isoflavonoid phytoalexins re­ ported earlier [1], the mung bean, Phaseolus aureus, produces coumestrol ( 1 ) and two novel coumestans, aureol (2) and phaseol (3). Coumestrol has been isolated from this plant previously [2 ] and the present communication describes the isolation and structural characterization of the latter two com­ pounds. The characterizations of aureol and p...

This work describes the comparison of the amplification characteristics (gain) and the Noise figure (NF) of the Thulium and Erbium in three different host materials which the Yttria Alumina-Silica glass, Fluoride and Tellurite fiber glass. The gain using these host materials covers the range 1.45-1.65 μm. Thulium doped fiber amplifier (TDFAs) operated in the region of wavelength (1480-1510 nm) ...