Ryan M. Gelfand

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We present a new structure that combines a metal-dielectric-metal sandwich with a periodic structure to form a plasmon polariton photonic crystal. Three-dimensional finite-difference time-domain simulations show a clear bandgap in the terahertz regime. We exploited this property by adding a defect to the crystal, which produces a cavity with a quality(More)
We report on a novel nanoinjection-based shortwave infrared imager, which consists of InGaAs/GaAsSb/InAlAs/InP-based nanoinjection detectors with internal gain. The imager is 320Â256 pixels with a 30-m pixel pitch. The test pixels show responsivity values in excess of 2500 A/W, indicating generation of more than 2000 electrons/photon with high quantum(More)
We report on the signal-to-noise performance of a nanoinjection imager, which is based on a short-wave IR InGaAs/GaAsSb/InP detector with an internal avalanche-free amplification mechanism. Test pixels in the imager show responsivity values reaching 250 A/W at 1550 nm, -75 degrees C, and 1.5V due to an internal charge amplification mechanism in the(More)
We present spatial mapping of optical force generated near the hot spot of a metal-dielectric-metal bowtie nanoantenna at a wavelength of 1550 nm. Maxwell's stress tensor method has been used to simulate the optical force and it agrees well with the experimental data. This method could potentially produce field intensity and optical force mapping(More)
—Exploiting optical nano-antennas to boost the near-field confinement within a small volume can increase the limit of molecular detection by an order of magnitude. We present a novel antenna design based on Au–SiO 2 –Au single nanorod integrated on the facet of a quantum cascade laser operating in the midinfrared region of the optical spectrum.(More)
Optical nanoantennas are capable of enhancing the near-field intensity and confining optical energy within a small spot size. We report a novel metal-dielectric-metal coupled-nanorods antenna integrated on the facet of a quantum-cascade laser. Finite-difference time-domain simulations showed that, for dielectric thicknesses in the range from 10 to 30 nm,(More)
We report a type of infrared switchable plasmonic quantum cascade laser, in which far field light in the midwave infrared (MWIR, 6.1 μm) is modulated by a near field interaction of light in the telecommunications wavelength (1.55 μm). To achieve this all-optical switch, we used cross-polarized bowtie antennas and a centrally located germanium nanoslab. The(More)
We present metal-dielectric-metal bow-tie antenna integrated Quantum Cascade Laser where the optical mode has been squeezed within ~ 100nm and its interaction with AFM tip (~50nm) can affect laser cavity mode (~6um). Such compact device with high sensitivity can be useful for building mid-infrared bio-sensors. Sensitivity is a key requirement to upgrade any(More)
Spatial mapping of optical force near the hot-spot of a metal-dielectric-metal bow-tie nanoantenna at a wavelength of 1550 nm is presented. Non contact mode atomic force microscopy is used with a lock-in method to produce the map. Maxwell's stress tensor method has also been used to simulate the force produced by the bow-tie and it agrees with the(More)
We present experimental spatial mapping of optical force generated by the plasmonic mode confinement of a nanoantenna at 1550 nm. Maxwell's stress tensor method is used to simulate the force map and it agrees well with the experimental data. Radiation pressure and optical force originate from the elastic scattering of photons with a momentum of h/λ. It has(More)