Controlling the spectral width in compound waveguide grating structures

Liu, Wenxing; Li, Yunhui; Jiang, Haitao; Lai, Zhenquan; Chen, Hong

doi:10.1364/ol.38.000163

Cited by 53 publications

(27 citation statements)

References 19 publications

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“…As d/p decreases from 1 to 0, the responsivity peaks tend to move along a line of the same order FP resonance. According to effective medium theory, [34][35][36] a subwavelength grating can be replaced by a homogeneous, isotropic layer with an appropriate effective index. The effective indices of a 1D subwavelength grating are given by…”

Section: Resultsmentioning

confidence: 99%

Simulation and analysis of grating-integrated quantum dot infrared detectors for spectral response control and performance enhancement

Kim¹,

Ku²,

Krishna³

et al. 2014

Journal of Applied Physics

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High-speed >90% quantum-efficiency p-i-n photodiodes with a resonance wavelength adjustable in the 795-835 nm range Appl. Phys. Lett. 74, 1072Lett. 74, (1999 We propose and analyze a novel detector structure for pixel-level multispectral infrared imaging. More specifically, we investigate the device performance of a grating-integrated quantum dots-in-a-well photodetector under backside illumination. Our design uses 1-dimensional grating patterns fabricated directly on a semiconductor contact layer and, thus, adds a minimal amount of additional effort to conventional detector fabrication flows. We show that we can gain wide-range control of spectral response as well as large overall detection enhancement by adjusting grating parameters. For small grating periods, the spectral responsivity gradually changes with parameters. We explain this spectral tuning using the Fabry-Perot resonance and effective medium theory. For larger grating periods, the responsivity spectra get complicated due to increased diffraction into the active region, but we find that we can obtain large enhancement of the overall detector performance. In our design, the spectral tuning range can be larger than 1 lm, and, compared to the unpatterned detector, the detection enhancement can be greater than 92% and 148% for parallel and perpendicular polarizations. Our work can pave the way for practical, easy-to-fabricate detectors, which are highly useful for many infrared imaging applications. V C 2014 AIP Publishing LLC.[http://dx

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Section: Resultsmentioning

confidence: 99%

Simulation and analysis of grating-integrated quantum dot infrared detectors for spectral response control and performance enhancement

Kim¹,

Ku²,

Krishna³

et al. 2014

Journal of Applied Physics

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show abstract

“…It is generally accepted that blazed, compound, and complex gratings can be harnessed for the design of spectral and spatial distribution of transmitted, reflected, and guided light modes with improved desired properties such as enhancement or improved coherence of emitted radiation [150]. These kinds of grating can be used for beam shaping [151,152], spectroscopy [153], and spectral filtering [154]. Coherent SP radiation, generated by the passage of relativistic short-bunched electrons across the surface of a metallic grating, has been observed in the wavelength region from 0.5 to 4.0 mm [155].…”

Section: Smith-purcell Sourcesmentioning

confidence: 99%

Electron-driven photon sources for correlative electron-photon spectroscopy with electron microscopes

et al. 2020

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Electron beams in electron microscopes are efficient probes of optical near-fields, thanks to spectroscopy tools like electron energy-loss spectroscopy and cathodoluminescence spectroscopy. Nowadays, we can acquire multitudes of information about nanophotonic systems by applying space-resolved diffraction and time-resolved spectroscopy techniques. In addition, moving electrons interacting with metallic materials and optical gratings appear as coherent sources of radiation. A swift electron traversing metallic nanostructures induces polarization density waves in the form of electronic collective excitations, i.e., the so-called plasmon polariton. Propagating plasmon polariton waves normally do not contribute to the radiation; nevertheless, they diffract from natural and engineered defects and cause radiation. Additionally, electrons can emit coherent light waves due to transition radiation, diffraction radiation, and Smith-Purcell radiation. Some of the mechanisms of radiation from electron beams have so far been employed for designing tunable radiation sources, particularly in those energy ranges not easily accessible by the state-of-the-art laser technology, such as the THz regime. Here, we review various approaches for the design of coherent electron-driven photon sources. In particular, we introduce the theory and nanofabrication techniques and discuss the possibilities for designing and realizing electron-driven photon sources for on-demand radiation beam shaping in an ultrabroadband spectral range to be able to realize ultrafast few-photon sources. We also discuss our recent attempts for generating structured light from precisely fabricated nanostructures. Our outlook for the realization of a correlative electron-photon microscope/spectroscope, which utilizes the above-mentioned radiation sources, is also described.

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“…Assume that the total width of the two grating grooves in each period is kept constant, that is, fb+fc=0.4. According to the rigorous coupled-wave theory [22], the grating Fourier harmonics εn control the amplitude of evanescent diffraction fields and are responsible for the mutual interaction of the evanescent diffraction fields, which have the following forms [23]:ε0=1−fb−fcnSi2+fb+fcnAir2,εn=nSi2−nAir2sinnπ1−fc−sinnπfbnπ, where nSi and nAir represent the refractive indexes of silicon and air, respectively. n is equal to ±1,±2,…±normalN…”

Section: Design For Two-part-period and Three-part-period Gratingsmentioning

confidence: 99%

Ultra-Broadband Absorption from 750.0 nm to 5351.6 nm in a Novel Grating Based on SiO2-Fe-Sandwich Substrate

Liu

Yang³

et al. 2019

Materials

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In this paper, we design a three-part-period grating based on alternating Fe/SiO 2 sandwich structure, which can achieve an ultra-broadband absorption from 750.0 nm to 5351.6 nm. In particular, the absorbing efficiency can reach to more than 95% within 2158.8 nm, which is due to the well impedance matching of Fe with the free space, as well as due to the excitation of localized surface plasmon resonance and surface propagation plasmon resonance in the proposed structure. Furthermore, multiple period gratings are also discussed to broaden the absorption band. These results are very promising for applications in high-performance photovoltaics, nonlinear optics devices and protective equipment for laser weapons.

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Controlling the spectral width in compound waveguide grating structures

Cited by 53 publications

References 19 publications

Simulation and analysis of grating-integrated quantum dot infrared detectors for spectral response control and performance enhancement

Simulation and analysis of grating-integrated quantum dot infrared detectors for spectral response control and performance enhancement

Electron-driven photon sources for correlative electron-photon spectroscopy with electron microscopes

Ultra-Broadband Absorption from 750.0 nm to 5351.6 nm in a Novel Grating Based on SiO2-Fe-Sandwich Substrate

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