Apparatus, systems, and methods for on-chip spectroscopy using optical switches
First Claim
1. A spectrometer, comprising:
- a beam splitter to split incident light into a first portion and a second portion;
a first interference arm, in optical communication with the beam splitter, to receive the first portion of the incident light, the first interference arm comprising;
a first optical switch switchable between a first state and a second state;
a first waveguide having a first optical path length L1 to receive the first portion of the incident light when the first optical switch is in the first state; and
a second waveguide having a second optical path length L2, different than the first optical path length L1, to receive the first portion of the incident light when the first optical switch is in the second state;
a second interference arm, in optical communication with the beam splitter, to receive the second portion of the incident light; and
a single-element detector, in optical communication with the first interference arm and the second interference arm, to detect interference of the first portion of the incident light from the first interference arm and the second portion of the incident light from the second interference arm.
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Accused Products
Abstract
A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.
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Citations
20 Claims
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1. A spectrometer, comprising:
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a beam splitter to split incident light into a first portion and a second portion; a first interference arm, in optical communication with the beam splitter, to receive the first portion of the incident light, the first interference arm comprising; a first optical switch switchable between a first state and a second state; a first waveguide having a first optical path length L1 to receive the first portion of the incident light when the first optical switch is in the first state; and a second waveguide having a second optical path length L2, different than the first optical path length L1, to receive the first portion of the incident light when the first optical switch is in the second state; a second interference arm, in optical communication with the beam splitter, to receive the second portion of the incident light; and a single-element detector, in optical communication with the first interference arm and the second interference arm, to detect interference of the first portion of the incident light from the first interference arm and the second portion of the incident light from the second interference arm. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A spectrometer, comprising:
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a beam splitter to split incident light into a first portion and a second portion; a first interference arm, in optical communication with the beam splitter, to receive the first portion of the incident light, the first interference arm comprising N cascaded M-output optical switches to direct the first portion along one of MN possible optical paths, where N is an integer greater than one and each of the MN possible optical paths has a different optical path length; a second interference arm, in optical communication with the beam splitter, to receive the second portion of the incident light; and a detector, in optical communication with the first interference arm and the second interference arm, to detect interference of the first portion of the incident light from the first interference arm and the second portion of the incident light from the second interference arm. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A method of using a spectrometer comprising N cascaded M-output optical switches, where M and N are integers greater than one, the method comprising:
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splitting incident light into a first portion and a second portion; directing the first portion along at least one of MN possible optical paths via the N cascaded M-output optical switches, each of the MN possible optical paths having a different optical path length; detecting interference between the first portion and the second portion at the end of the at least one of the MN possible optical paths; and determining a spectrum of the incident light based on the interference between the first portion and the second portion. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification