Topic
Photonic crystal
About: Photonic crystal is a research topic. Over the lifetime, 43424 publications have been published within this topic receiving 887083 citations.
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TL;DR: In this article, an index-guiding photonic crystal fiber with an array of air holes surrounding the silica core region has been shown to have special characteristics compared with conventional single-mode fibers.
Abstract: Recent progress on numerical modeling methods for photonic crystal fibers (PCFs) such as the effective index approach, basis-function expansion approach, and numerical approach is described. An index-guiding PCF with an array of air holes surrounding the silica core region has special characteristics compared with conventional single-mode fibers (SMFs). Using a full modal vector model, the fundamental characteristics of PCFs such as cutoff wavelength, confinement loss, modal birefringence, and chromatic dispersion are numerically investigated.
251 citations
TL;DR: In this paper, a new type of omnidirectional gaps is theoretically found in one-dimensional photonic crystals (1DPCs) composed of two kinds of single-negative (SNG) materials.
Abstract: A new type of omnidirectional gaps is theoretically found in one-dimensional photonic crystals (1DPCs) composed of two kinds of single-negative (SNG) (permittivity- or permeability-negative) materials. In contrast to the Bragg gaps, the properties (the central frequency and width of the gap) of such omnidirectional gaps are insensitive to the incident angles and the light polarizations, and are invariant upon the change of scale length. Such omnidirectional gaps result from the interaction of evanescent waves. When a defect layer is introduced, a defect mode appears inside the omnidirectional gap, and the spectral position of the defect mode is almost independent of incident angles and nearly invariant with the scaling.
250 citations
TL;DR: The present paper reports on the first successful continuous-wave operation at room temperature for the smallest nanolaser reported to date, achieved through fabrication of a laser with a low threshold of 1.2 muW.
Abstract: Photonic crystal slab enables us to form an ultrasmall laser cavity with a modal volume close to the diffraction limit of light. However, the thermal resistance of such nanolasers, as high as 10(6) K/W, has prevented continuous-wave operation at room temperature. The present paper reports on the first successful continuous-wave operation at room temperature for the smallest nanolaser reported to date, achieved through fabrication of a laser with a low threshold of 1.2 muW. Near-thresholdless lasing and spontaneous emission enhancement due to the Purcell effect are also demonstrated in a moderately low Q nanolaser, both of which are well explained by a detailed rate equation analysis.
250 citations
TL;DR: This review focuses on single nanoparticle detection using optical whispering gallery microcavities and photonic crystal microc Cavities, both of which have been developing rapidly over the past few years.
Abstract: Detection of nanoscale objects is highly desirable in various fields such as early-stage disease diagnosis, environmental monitoring and homeland security. Optical microcavity sensors are renowned for ultrahigh sensitivities due to strongly enhanced light-matter interaction. This review focuses on single nanoparticle detection using optical whispering gallery microcavities and photonic crystal microcavities, both of which have been developing rapidly over the past few years. The reactive and dissipative sensing methods, characterized by light-analyte interactions, are explained explicitly. The sensitivity and the detection limit are essentially determined by the cavity properties, and are limited by the various noise sources in the measurements. On the one hand, recent advances include significant sensitivity enhancement using techniques to construct novel microcavity structures with reduced mode volumes, to localize the mode field, or to introduce optical gain. On the other hand, researchers attempt to lower the detection limit by improving the spectral resolution, which can be implemented by suppressing the experimental noises. We also review the methods of achieving a better temporal resolution by employing mode locking techniques or cavity ring up spectroscopy. In conclusion, outlooks on the possible ways to implement microcavity-based sensing devices and potential applications are provided.
250 citations
TL;DR: In this article, two AB GaAs field effect transistor (FET) power amplifiers have been designed and fabricated in the 4.4-4.8 GHz range, and a dielectric PBG line was incorporated in the design to tune the second harmonic.
Abstract: Two class AB GaAs field-effect transistor (FET) power amplifiers have been designed and fabricated in the 4.4-4.8 GHz range. In the first case, a dielectric PBG line was incorporated in the design to tune the second harmonic. In the second case, a 50-/spl Omega/ line is used with no harmonic tuning. The PBG structure allows broad-band harmonic tuning and is inexpensive to fabricate. A 5% improvement in power-added efficiency was achieved at the design frequency of 4.5 GHz, in both simulation and measurement.
250 citations