Systems and methods for Raman spectroscopy
AssigneeMassachusetts Institute of Technology
InventorsJuejun Hu, Derek Kita, Jerome Michon
Life of this patent
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Abstract
A method of performing Raman spectroscopy can include guiding a Raman pump beam with an optical fiber, where the Raman pump beam inducing fluorescence in the optical fiber. The beam and the fluorescence are coupled to a photonic integrated circuit (PIC) via the fiber. The beam is used to excite a sample in optical communication with the PIC via evanescent coupling and induces Raman scattering in the sample. The Raman scattering is collected via the PIC, and the Raman pump beam as well as the fluorescence is filtered out from the Raman scattering via the PIC.
Claims23
A photonic integrated circuit (PIC) for Raman spectroscopy, the PIC comprising:
- a semiconductor substrate;
- a multi-port optical coupler, integrated with the semiconductor substrate and having a first port, a second port, and a third port, to receive a Raman pump beam and fluorescence induced by the Raman pump beam in an optical fiber at the first port, and to output the Raman pump beam and the fluorescence at the second port;
- a sample waveguide, integrated with the semiconductor substrate and coupled to the second port, to guide the Raman pump beam and the fluorescence in a first direction, to excite a sample in optical communication with the sample waveguide with the Raman pump beam via evanescent coupling, to receive a scattering signal from the sample in response to the excitation, and to guide the scattering signal in a second direction opposite from the first direction;
- and
- an output waveguide, integrated with the semiconductor substrate and coupled to the third port of the multi-port optical coupler, to guide the scattering signal to a detector,
- wherein the multi-port optical coupler has a first splitting ratio at a wavelength of the Raman pump beam and a second splitting ratio different than the first splitting ratio at a wavelength of the scattering signal.
A method of Raman spectroscopy, comprising:
- receiving, via an optical fiber, at a first port of a multi-port optical coupler integrated with a semiconductor substrate of a photonic integrated chip (PIC), a Raman pump beam and fluorescence induced by the Raman pump beam in the optical fiber;
- coupling, by the multi-port optical coupler, the Raman pump beam from the first port to a second port of the multi-port optical coupler at a first coupling ratio;
- guiding, via a sample waveguide coupled to the second port, the Raman pump beam and the fluorescence away from the second port;
- exciting a sample in optical communication with the sample waveguide with the Raman pump beam via evanescent coupling;
- receiving, via the sample waveguide, a scattering signal from the sample in response to the excitation;
- guiding, via the sample waveguide, the scattering signal towards the second port;
- coupling, by the multi-port optical coupler, the scattering signal from the second port to a third port of the multi-port optical coupler at a second coupling ratio different than the first coupling ratio;
- and
- guiding, via an output waveguide coupled to the third port, the scattering signal to a detector.
Dependencies are inferred from the claim text.