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公开(公告)号：US20240369901A1
公开(公告)日：2024-11-07
申请号：US18570953
申请日：2022-04-15
Applicant: Massachusetts Institute of Technology
Inventor： Gavin WEST , Rajeev J. RAM
Abstract: An integrated acousto-optic modulator operates with an extremely high extinction ratio (e.g.,>50 dB) thanks to two widely separated two-dimensional (2D) waveguides. These 2D waveguides are formed on or adjacent to a one-dimensional (ID) wave-guide far enough apart (e.g., 10-100 pm apart) to prevent evanescent coupling between them. An acoustic transducer formed on the surface of the ID waveguide switches light from one 2D waveguide to the other 2D waveguide via the ID waveguide. The acoustic wave emitted by the acoustic transducer forms a traveling grating that overlaps with one 2D waveguide. diffracting light from that 2D waveguide into the ID waveguide, which guides the light to the other 2D waveguide. A lateral grating coupler diffracts this light from the ID waveguide into a mode guided by the other 2D waveguide. This acoustic modulator acts as a switch suitable for use in quantum and atomic systems.
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2.发明公开公开(公告)号：US20240344991A1
公开(公告)日：2024-10-17
申请号：US18685153
申请日：2022-08-19
Inventor： Pil Joong CHUNG , Sayuj KOYYAPPURATH , Nam-Hai CHUA , Rajani SAROJAM , Gajendra Pratap SINGH , Rajeev J. RAM
CPC classification number: G01N21/65 , G01N33/0098
Abstract: The present invention relates to the use of Raman spectroscopy for the real time detection and quantitation of innate immunity response in plants. More specifically, the present invention provides Raman spectroscopy as a tool for rapid, non-invasive, and early detection and quantitation of plant innate immune response.
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Patent Agency Ranking
公开(公告)号：US20230243750A1
公开(公告)日：2023-08-03
申请号：US17999331
申请日：2021-05-20
Inventor： In-Cheol JANG , Benny Jian Rong SNG , Gajendra Pratap SINGH , Rajeev J. RAM
CPC classification number: G01N21/65 , G01N21/84 , G01N33/0098 , G01N2021/8466
Abstract: The present invention relates to the use of a Raman spectral signature for detection of plant metabolites, specifically carotenoids, in tissue of a plant leaf. Carotenoids are used as a biomarker for an early, real-time diagnosis of shade avoidance syndrome (SAS) in growing plants in a non-invasive or non-destructive way in order to detect the adverse effect of the SAS upon their health, and ultimately their yield. The early, real-time diagnosis of SAS provides a window period within which further adverse effects of SAS may be slowed or prevented without negatively affecting the yield of growing plants or leafy vegetables.
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4.发明公开公开(公告)号：US20230184684A1
公开(公告)日：2023-06-15
申请号：US17999312
申请日：2021-05-20
Inventor： Bong Soo PARK , Rajeev J. RAM , Chung Hao HUANG , Gajendra Pratap SINGH , Nam-Hai CHUA
CPC classification number: G01N21/65 , G01N21/84 , G01N33/0098 , A01C21/007 , G01N2021/8466
Abstract: The present invention relates to the use of a Raman spectral signature of nitrate, as a biomarker for an early, real-time diagnosis of nitrogen status in growing plants in a non-invasive or non-destructive way in order to detect nitrogen deficiency before the onset of any visible symptoms. The early, real-time diagnosis of nitrogen deficiency in plants makes it possible to correct nitrogen deficiency for the avoidance of negative effects on the yield and biomass of growing plants or leafy vegetables.
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公开(公告)号：US20230139185A1
公开(公告)日：2023-05-04
申请号：US17765361
申请日：2021-12-10
Applicant: Massachusetts Institute of Technology
Inventor： Rajeev J. RAM , Jaehwan Kim , Jin Xue , Zheng Li
IPC: H01L27/15
Abstract: Light-emitting diodes having radiative recombination regions with deep sub-micron dimensions are described. The LEDs can be fabricated from indirect bandgap semiconductors and operated under forward bias conditions to produce intense light output from the indirect bandgap material. The light output per unit emission area can be over 500 W cm−2, exceeding the performance of even high brightness gallium nitride LEDs.
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公开(公告)号：US20210116298A1
公开(公告)日：2021-04-22
申请号：US16853811
申请日：2020-04-21
Applicant: Massachusetts Institute of Technology
Inventor： Amir H. Atabaki , Rajeev J. RAM , William F. Herrington
Abstract: In swept source Raman (SSR) spectroscopy, a swept laser beam illuminates a sample, which inelastically scatters some of the incident light. This inelastically scattered light is shifted in wavelength by an amount called the Raman shift. The Raman-shifted light can be measured with a fixed spectrally selective filter and a detector. The Raman spectrum can be obtained by sweeping the wavelength of the excitation source and, therefore, the Raman shift. The resolution of the Raman spectrum is determined by the filter bandwidth and the frequency resolution of the swept source. An SSR spectrometer can be smaller, more sensitive, and less expensive than a conventional Raman spectrometer because it uses a tunable laser and a fixed filter instead of free-space propagation for spectral separation. Its sensitivity depends on the size of the collection optics. And it can use a nonlinearly swept laser beam thanks to a wavemeter that measures the beam's absolute wavelength during Raman spectrum acquisition.
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公开(公告)号：US20200103281A1
公开(公告)日：2020-04-02
申请号：US16704444
申请日：2019-12-05
Applicant: Massachusetts Institute of Technology
Inventor： Erika Ye , Amir H. Atabaki , Ningren Han , Rajeev J. RAM , William F. Herrington
Abstract: A non-paraxial Talbot spectrometer includes a transmission grating to receive incident light. The grating period of the transmission grating is comparable to the wavelength of interest so as to allow the Talbot spectrometer to operate outside the paraxial limit. Light transmitted through the transmission grating forms periodic Talbot images. A tilted detector is employed to simultaneously sample the Talbot images at various distances along a direction perpendicular to the grating. Spectral information of the incident light can be calculated by taking Fourier transform of the measured Talbot images or by comparing the measured Talbot images with a library of intensity patterns acquired with light sources having known wavelengths.
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