Abstract: Wavelength selection apparatus for use in various applications such as spectrometry, the demultiplexing/multiplexing of multiline laser beams, and so forth, includes an input prism and an output prism aligned along an optical axis, and at least one side mirror. A second side mirror spaced from the first side mirror on the opposite side of the optical axis may be provided, as well as end mirrors adjacent to the input and output prisms. An incoming beam incident upon the input prism is refracted so as to deflect and angularly disperse the various wavelengths present in the input beam, with the dispersing beam reflected from the first side mirror either directly to the output prism or with intermediate reflections from the second side mirror and the end mirrors before impinging upon the output prism. The output prism matches the input prism and deflects and recollimates the dispersed wavelengths to provide parallel output beams of different wavelengths spaced from one another.
Abstract: Flash photolysis is carried out in a microscope imaging system while maintaining continuous and superimposed imaging of the target area to which the flash is directed as well as its surroundings. In scanning imaging systems an excitation optical coupler receives the flash excitation beam and directs it onto an optical path through an aperture spatial filter to a main optical coupler, which directs the excitation beam into the microscope. The scanning beam from the scanning system is also passed through the main optical coupler to the microscope and the reflected light from the specimen is passed back from the microscope through the main optical coupler to the scanning system in a normal fashion to allow imaging of the specimen when the excitation beam is not provided.
Abstract: An x-ray collimator for wavelength dispersive spectroscopy and the like includes a grazing incidence mirror optic having a polycapillary x-ray optic nested therein. The polycapillary x-ray optic is mounted in a hollow bore of the grazing incidence mirror optic so as not to interfere with operation of the grazing incidence mirror. The polycapillary x-ray optic extends the range of the grazing incidence mirror optic to higher energy ranges. The x-ray collimator of the present invention may be employed in a wavelength dispersive x-ray spectrometer including a diffracting element positioned to receive x-rays collimated by the x-ray collimator, and an x-ray detector positioned to receive the x-rays defracted by the diffracting element. A wavelength dispersive x-ray spectrometer in accordance with the present invention may be used in combination with an energy beam microscope, such as an electron microscope, to analyze x-rays emanating from a sample specimen.
Abstract: A two-piece collimator for use in high takeoff angle energy dispersive spectroscopy (EDS) is provided. The two-piece collimator includes a base section and an extension section. The collimator base section may be attached rigidly to the end of an EDS detector tube. The collimator extension section is removably attached to and extends from the base section. Apertures through the base and extension sections are easily aligned with each other and with an EDS detector. The length of the collimator extension section is preferably selected such that the distal end of the extension section extends below the bottom of an upper pole piece of an electron microscope in which the collimator is employed. A two-piece collimator in accordance with the present invention effectively reduces stray radiation, including back scattered electrons, which may cause artifacts in a detected EDS X-ray spectrum.
Abstract: An improved X-ray spectrometer detector system includes a mechanical cooling system with a compressor connected by supply and return lines to a cryocooler connected to an X-ray dispersive spectrometer detector for an electron microscope. Within a housing containing a cryocooler heat exchanger, a heat sink thermal mass is thermally connected to a cold finger heat conducting structure which has the X-ray detector mounted at its distal end. The housing insulates the cryocooler heat exchanger and the heat sink from the external ambient. The compressor unit is operated to cool the detector to a desired low operating temperature at which precision measurements may be made. When such measurements are to be made, the compressor is turned off to minimize vibrations that could interfere with X-ray detector measurements or the operation of the electron microscope.
Abstract: A noisy signal obtained from an acquisition system, such as a conventional or confocal microscope, is reconstructed in a manner which simultaneously estimates the true or ideal signal as well as the response function of the acquisition system. The restored signal can be a function of one or more variables, e.g., time or space. Prior knowledge of the response function of the acquisition system is not required, there is no the need to calibrate the acquisition system before acquiring a signal. The true signal and the response function of the acquisition system are estimated in iterative manner. The actual signal data and the frequency content of the actual signal data may be used to determine constraints to be applied to the estimates of the true signal and the impulse response of the acquisition system. These constraints include constraints on the signal (in the spatial domain) and constraints in the frequency domain.