摘要:
A broadband optical accumulator and tunable narrowband optical source use a microstructured optical fiber into which optical energy is coupled at a first wavelength. The input optical energy is spectrally broadened as it propagates through the fiber, and the output signal is directed to a wavelength separator such as a Bragg grating. A narrowband portion of the output signal is redirected by the grating, while the remainder is reinjected into the fiber. Adjustment of the output wavelength band may be accomplished by changing the incidence angle of the output signal by pivoting the grating. The grating may be located in a housing and surrounded by index matching fluid, and the narrowband portion of the output signal isolated by the grating may be redirected to an output location by a reflector that moves with pivoting of the grating.
摘要:
A laser induced breakdown spectroscopy (LIBS) system uses discrete optical filters for isolated predetermined spectral components from plasma light created by ablation of a sample. Independent detection elements may be used for detecting the magnitude for each spectral component. A first spectral component may include a characteristic wavelength of the sample, while a second spectral component may be a portion of a background continuum. The filters may include volume Bragg gratings and the detectors may be photodiodes. A detector that detects plasma light remaining after the isolation of the predetermined spectral components may be used together with a signal acquisition controller to precisely control the initiation and termination of signal acquisition from each of the detection elements. The system may also have optics including a collimating lens through which passes both the initial plasma light and the isolated spectral components.
摘要:
A notch filter system, where multiple filter passes of a light signal may be effected for removing a target spectral component from the light signal, is provided. Advantageously, the notch filter system may be tunable. A cascade notch filter system is provided which includes multiple notch filters arranged in a cascade, each of the filters having spectral filtering characteristics and being disposed in the path of the light signal at an appropriate filter angle so that the target spectral component is filtered out of the light signal as the light signal passes therethrough. A multipass notch filter system is provided which includes a notch filter having spectral filtering characteristics, and an optical assembly for directing the light signal for multiple filter passes through the filter at an appropriate angle, so that the target spectral component is filtered out of the light signal as the light signal passes through the filter.