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Graphene is emerging as a broadband optical material which can be dynamically tuned by electrostatic doping. However, direct application of grapheme sheets in optoelectronic devices is challenging due to its small thickness and the resultant weak interaction with light. By combining metal and graphene in a hybrid plasmonic structure, it is possible to enhance graphene-light interaction and thus achieve in situ control of the optical response. We show that the effective mode index of the bonding plasmonic mode in metal-insulator-metal (MIM) waveguides is particularly sensitive to the change in the optical conductivity of a graphene layer in the gap. By incorporating such MIM structures in optic antenna designs, we demonstrate an electrically tunable coupled antenna array on graphene with a large tuning range (1100 nm, i.e. 250 cm-1, nearly 20% of the resonance frequency) of the antenna resonance wavelength at the mid-infrared (MIR) region. Our device exhibits a 3dB cut-off frequency of 30 MHz, which can be further increased into the GHz range. This study confirms that hybrid metal-graphene structures are promising elements for high-speed electrically controllable optical and optoelectronic devices.
This article was published in the following journal.
Name: Nano letters
The design of an integrated graphene-based fine-tunable optical delay line on silicon nitride for optical beamforming in phased-array antennas is reported. A high value of the optical delay time (τg=...
Wavelength tuning of conventional mirror-based optical parametric oscillators (OPOs) exhibits parabolically-shaped tuning curves (type-0 and type-I phase matching) or tuning branches that cross each o...
Optical antennas enable the control of light-matter interaction on the nanometer scale. Efficient on-chip electrical switching of plasmonic resonances is a crucial step toward the integration of optic...
An ultra-broadband tunable cascaded Raman random fiber laser pumped by a tunable (1020-1080 nm) ytterbium-doped fiber laser is investigated. By continuously adjusting the pump laser wavelength, the R...
The independent excitation and tuning of double plasmonic waves are realized in a free-standing graphene-spacer-grating-spacer-graphene (GSGSG) hybrid slab, which consists of two graphene field effect...
We have developed a safe, non-contact, intra-operative guidance system to optimize tumor resection in neurosurgery. The Modulated Imaging (MI) is non-contact optical imaging technology dev...
The purpose of this investigation is to study the effectiveness of longer wavelength UVA1 (340-400nm) or shorter wavelength ultraviolet B [UVB] (290-320nm) irradiation in the treatment of ...
The macular pigment (MP) in humans consists of the yellow, blue-absorbing carotenoids lutein and zeaxanthin, which are contained in vegetables and fruits. The highest concentrations of lut...
Traditional biopsy requires the removal, fixation, and staining of tissues from the human body. Its procedure is invasive and painful. Non-invasive in vivo optical biopsy is thus required,...
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Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.
Products or parts of products used to detect, manipulate, or analyze light, such as LENSES, refractors, mirrors, filters, prisms, and OPTICAL FIBERS.
An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.
Scattering of a beam of electromagnetic or acoustic RADIATION, or particles, at small angles by particles or cavities whose dimensions are many times as large as the wavelength of the radiation or the de Broglie wavelength of the scattered particles. Also know as low angle scattering. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed) Small angle scattering (SAS) techniques, small angle neutron (SANS), X-ray (SAXS), and light (SALS, or just LS) scattering, are used to characterize objects on a nanoscale.
Behavior of LIGHT and its interactions with itself and materials.
A diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease. For example: to diagnose diseases to measure the progress or recovery from disease to confirm that a person is free from disease Clin...