In summary, we proposed and demonstrated a C band TEDFL which employs a BFM and a TFBG to form the laser cavity. The BFM acts as a broadband reflector both for the lasing signal and pump source. At pumping power of 100 mW, stable laser output power of 21.35 dBm is obtained with the threshold pumping power as small as 4.7 mW. A SMSR of 57.9 dB and 16 nm tuning range are demonstrated. This BFM-based TEDFL with graceful features as mentioned may find vast applications in fiber optics communications and fiber sensor technology. , Temperature-tuned erbium-doped fiber ring laser with polymer-coated fiber grating, Opt Commun 202 (2002), 331-334. ABSTRACT: In handheld communications devices there is not much room for the placement of antennas. This problem is exacerbated when more than one antenna is needed for use in a MIMO communications system. It is then useful to be able to utilize some of the existing device structure to form the required antennas. In this article, we show how the characteristic mode theory can be used to achieve this in a way that results in antennas with the low envelope correlation preferred for MIMO antennas. ABSTRACT: A broadband, circular switched parasitic array with two active elements, suitable for DVB-T applications at the V-UHF band is designed with the aid of a genetic algorithm. Numerical as well as measurements results are presented for a single switch position. Simulation results are also presented for switched-beam array operation, using the measured antenna radiation patterns.
When using a high-resolution Fourier transform spectrometer (FTS) in a cube-corner configuration, subharmonic ghosts are observed in the spectrum. These ghosts are attributable to parasitic diffuse reflections on the mirrors of the FTS arm. The reflected beams skip a part of the interferometer and travel a different path from the main beam thus experiencing a smaller optomechanical gain. These reflections are present in the reference laser channel as well as on the measurement channel, and each affect the estimated spectrum differently. The sampling grid generated by the reference laser has periodic errors that are synchronized with the fringe signal. The measured spectrum can therefore exhibit sampling jitter ghosts at submultiples of the reference laser wavenumber in addition to its own additive subharmonics. The diffuse reflection experiencing the nominal optomechanical gain, such as in a plane-mirror configuration, will impact directly on the instrument line shape and on the radiometric accuracy of the spectrometer since some radiation is not propagating at the expected angles in the instrument.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.