Abstract:
The present invention provides an improvement in a wavelength division multiplexer and/or a dense wavelength division multiplexer (WDM/DWDM) by incorporating an electronically reconfigurable diffraction grating (108). The introduction of the electronically reconfigurable diffraction grating (108), which is typically fabricated using MEMS (microelectromechanical systems) technology, improves the compact design, durability, and dynamic functionality of the WDM/DWDM system.
Abstract:
Plane diffraction grating 13 is formed of a material having an appropriate linear expansion coefficient and a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of members other than plane diffraction grating 13 is cancelled out or reduced by a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of plane diffraction grating 13. The same principle is used to deal with the effect on the wavelength of the diffracted light that may be caused by changes in the layout of individual members on account of thermal expansion or shrinkage of substrate 10a that fix them.
Abstract:
A biocompatible monomer composition includes: (A) at least one monomer, which forms a medically acceptable polymer; (B) at least one plasticizing agent present in the composition in an amount of from 0.5 wt. to 15 wt. % of the composition; and (C) at least one acidic stabilizing agent having a pKa ionization constant of from about 1 to about 7. The composition can be applied to a variety of materials and is particularly suitable as in vivo tissue adhesive. A method of joining together in vivo two surfaces, e.g., body tissues, includes (a) holding damaged tissue edges together to form abutted tissue surfaces; (b) applying to the abutted tissue surfaces an excessive amount of a composition containing 1) at least one monomer, which forms a medically acceptable biodegradable polymer, 2) at least one plasticizing agent; and 3) at least one acidic stabilizing agent; and (c) maintaining the surfaces in contact until the composition polymerizes to form a thick film of polymerized composition bridging the abutted tissue surfaces.
Abstract:
Disclosed are photometric methods and devices for determining optical pathlength of liquid samples containing analytes dissolved or suspended in a solvent. The methods and devices rely on determining a relationship between the light absorption properties of the solvent and the optical pathlength of liquid samples containing the solvent. This relationship is used to establish the optical pathlength for samples containing an unknown concentration of analyte but having similar solvent composition. Further disclosed are methods and devices for determining the concentration of analyte in such samples where both the optical pathlength and the concentration of analyte are unknown. The methods and devices rely on separately determining, at different wavelengths of light, light absorption by the solvent and light absorption by the analyte. Light absorption by the analyte, together with the optical pathlength so determined, is used to calculate the concentration of the analyte. Devices for carrying out the methods particularly advantageously include vertical-beam photometers containing samples disposed within the wells of multi-assay plates, wherein the photometer is able to monitor light absorption of each sample at multiple wavelengths, including in the visible or UV-visible region of the spectrum, as well as in the near-infrared region of the electromagnetic spectrum. Novel photometer devices are described which automatically determine the concentration of analytes in such multi-assay plates directly without employing a standard curve.
Abstract:
A spectrum analyzer providing an integrated calibration function and for providing that calibration function automatically. The injection of light to be analyzed through a central aperture of a scanning grating onto a focusing reflector provides in combination four traversals of the space therebetween. The spectrometer thus is used to separate wavelength information spacially and receive it back at the same or adjacent aperture(s) to be analyzed by a processing system to establish the spectra for the incident light. The light is typically injected from and received back into optical fibers or other light carrying elements. Calibration light is also applied through the same or adjacent apertures in the grating from a known source and spectra such as Argon to use as a calibration reference by detecting the known spectra peaks and correlating it to grating scan angle. The same structure is also used as a telecommunications channel router by injecting light of multi-channel and thus broadband spectral content into the spectrometer through the central aperture(s) and angling the grating so that a selected channel or channels are reflected back after four passages of the spectral separator to output one or more optical fibers or other guides.
Abstract:
The monochromator and the spectrometric method are disclosed wherein the measured beam converted into a parallel beam by a first collimator is diffracted by a plane diffraction grating, then the diffracted beam is returned so that the diffracted beam after the return is separated from that before the return along rulings of the plane diffraction grating, the diffracted beam is diffracted again by the plane diffraction grating, then the beam condensed by a second collimator is allowed to pass through an exit slit.
Abstract:
The invention provides a method and apparatus for determining the wavelength of a sample source of light, the apparatus having a reference light source of known wavelength, a collimator for collimating light from the sample source and from the reference source, a dispersing means for receiving and spatially dispersing collimated light from the collimator according to wavelength, focusing means for focusing dispersed light from the dispersing means, and a photodetector located in the focal plane of the focusing means and having an aperture for spatially selectively admitting light from the focusing means, and operable to provide a temporally calibratable output signal indicative of the wavelength of the selectively admitted light, wherein the apparatus is operable to scan the focused spatially dispersed beam across the aperture, and the photodetector output includes resolvable features corresponding to light from the reference source and sample source, whereby a time difference between the features is indicative of a wavelength difference between the light from the reference source and the sample source.
Abstract:
The present invention relates to a device and to a method for the excitation of fluorescent markers in multiphoton scanning microscopy, having at least one illumination beam path, a light source that produces the illumination light and at least one detection beam path for a detector, the objects to be studied being labelled with fluorescent markers. So as to avoid making it necessary to increase the illumination power of the light source in order to achieve an increase in the fluorescence photon yield, the device according to the invention and the method according to the invention are characterized in that at least one means that influences the spectral distribution/composition of the illumination light is provided for variably influencing the illumination light that excites the fluorescent markers, in particular during the illumination process.
Abstract:
Plane diffraction grating 13 is formed of a material having an appropriate linear expansion coefficient and a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of members other than plane diffraction grating 13 is cancelled out or reduced by a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of plane diffraction grating 13. The same principle is used to deal with the effect on the wavelength of the diffracted light that may be caused by changes in the layout of individual members on account of thermal expansion or shrinkage of substrate 10a that fix them.
Abstract:
Disclosed are photometric methods and devices for determining optical pathlength of liquid samples containing analytes dissolved or suspended in a solvent. The methods and devices rely on determining a relationship between the light absorption properties of the solvent and the optical pathlength of liquid samples containing the solvent. This relationship is used to establish the optical pathlength for samples containing an unknown concentration of analyte but having similar solvent composition. Further disclosed are methods and devices for determining the concentration of analyte in such samples where both the optical pathlength and the concentration of analyte are unknown. The methods and devices rely on separately determining, at different wavelengths of light, light absorption by the solvent and light absorption by the analyte. Light absorption by the analyte, together with the optical pathlength so determined, is used to calculate the concentration of the analyte. Devices for carrying out the methods particularly advantageously include vertical-beam photometers containing samples disposed within the wells of multi-assay plates, wherein the photometer is able to monitor light absorption of each sample at multiple wavelengths, including in the visible or UV-visible region of the spectrum, as well as in the near-infrared region of the electromagnetic spectrum. Novel photometer devices are described which automatically determine the concentration of analytes in such multi-assay plates directly without employing a standard curve.