Electrically-programmable optical processor with enhanced resolution
First Claim
1. An optical apparatus comprising a pair of diffraction gratings operable in tandem for processing light, the pair of diffraction gratings including a first diffraction grating having a first plurality of grating elements with a fixed spaced relationship therebetween, and a second diffraction grating having a second plurality of grating elements with an electrically-variable spaced relationship therebetween, one of the pair of diffraction gratings initially intercepting and processing the light and directing the light to the other of the pair of diffraction gratings for further processing.
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Accused Products
Abstract
An optical apparatus is disclosed for processing light that based on a pair of diffraction gratings operating in tandem, with one of the gratings being a fixed diffraction grating and with the other grating being electrically programmable. The combination of the fixed and electrically-programmable diffraction gratings provides a spectral resolution and dispersion higher than that of either diffraction grating when used alone. These two diffraction gratings can be formed on different substrates, or alternately be combined to form a composite diffraction grating. The electrically-programmable diffraction grating can be operated in either a singly-periodic mode or a multi-periodic mode to select particular wavelengths of the incident light for analysis and detection, or for transferring between optical fibers (e.g. wavelength division multiplexing or demultiplexing). In some cases, a prism can be substituted for the fixed diffraction grating or used in addition to the fixed grating. The optical apparatus has applications for use in remote spectral analysis, spectrometry, and optical fiber communications.
107 Citations
37 Claims
- 1. An optical apparatus comprising a pair of diffraction gratings operable in tandem for processing light, the pair of diffraction gratings including a first diffraction grating having a first plurality of grating elements with a fixed spaced relationship therebetween, and a second diffraction grating having a second plurality of grating elements with an electrically-variable spaced relationship therebetween, one of the pair of diffraction gratings initially intercepting and processing the light and directing the light to the other of the pair of diffraction gratings for further processing.
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18. An optical apparatus for processing light, comprising:
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(a) a first substrate having a fixed diffraction grating formed thereon, with the fixed diffraction grating further comprising a plurality of fixed grating elements; and
(b) a second substrate located proximate to the first substrate and having an electrically-programmable diffraction grating formed thereon, with the electrically-programmable diffraction grating further comprising a plurality of moveable grating elements, and with each moveable grating element being elongate and elastically mounted for movement relative to an adjacent grating element in response to a voltage applied between the grating element and an electrode formed proximate thereto, the fixed and electrically-programmable diffraction gratings operating in combination to sequentially process the light.
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28. An optical apparatus for processing light, comprising a composite diffraction grating formed on a substrate and having a first plurality of grating elements with an electrically-variable spaced relationship between adjacent grating elements of the first plurality of grating elements, and with each grating element in the first plurality of grating elements further having formed thereon a second plurality of grating elements in a fixed spaced relationship between adjacent grating elements of the second plurality of grating elements.
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35. A method for increasing the wavelength resolution of an electrically-programmable diffraction grating, comprising introducing a wavelength dispersing element into an optical path of the electrically-programmable diffraction grating.
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37. A method for processing light comprising steps for:
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(a) directing the light to a first diffraction grating for initial processing of the light by selecting a wavelength range of interest; and
(b) directing the light to a second diffraction grating for subsequent processing of the light by selecting at least one wavelength within the wavelength range of interest, with one of the first and second diffraction gratings having a fixed spaced relationship of grating elements therein, and with the other diffraction grating having an electrically-variable spaced relationship of grating elements therein.
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Specification