Transverse grating-assisted narrow-bandwidth acousto-optic tunable filter

1998 ◽  
Vol 23 (16) ◽  
pp. 1322 ◽  
Author(s):  
Eung Gi Paek ◽  
Joon Y. Choe ◽  
Tae K. Oh
Keyword(s):  
Tunable Filter ◽  
Narrow Bandwidth

scholarly journals A Technique for Tunable Filters with Low Insertion Loss and Narrow Bandwidth

2018 ◽  
Vol 38 ◽  
pp. 03039
Author(s):  
Chang Zhou ◽  
Chen Ji ◽  
Gen Ping Wu
Keyword(s):  
Insertion Loss ◽  
Return Loss ◽  
Tunable Filters ◽  
Tunable Filter ◽  
Center Frequency ◽  
Pin Diodes ◽  
Lc Filters ◽  
Narrow Bandwidth ◽  
Low Insertion Loss ◽  
Resonant Capacitor

A technique for tunable filters with low insertion loss and narrow bandwidth is proposed in the form of comb-line structure. Both resonant capacitor with pin-diodes and resonant inductance in the tunable filter were analyzed and the main source of insertion loss was obtained. A series of filters with same pin-diodes, center frequency, absolute bandwidth and low return loss was simulated. The results showed that, by changing the values of the resonant capacitor and inductance, insertion loss of the filter can be greatly restricted. This technique will allow the design of tunable LC filters with low insertion loss and narrow bandwidth.

Narrow-bandwidth all-fiber acoustooptic tunable filter with low polarization-sensitivity

2005 ◽  
Vol 17 (12) ◽  
pp. 2646-2648 ◽  
Author(s):  
Dong Il Yeom ◽  
Hyo Sang Kim ◽  
Myeong Soo Kang ◽  
Hee Su Park ◽  
Byoung Yoon Kim
Keyword(s):  
Tunable Filter ◽  
Polarization Sensitivity ◽  
Narrow Bandwidth

Narrow bandwidth liquid crystal tunable filter based on Lyot-Solc composite structure

2018 ◽  
Author(s):  
Xiaoqian Yang ◽  
Qi Guo ◽  
Huijie Zhao ◽  
Tianhao Zhang ◽  
Kexin Yan ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Composite Structure ◽  
Tunable Filter ◽  
Narrow Bandwidth

scholarly journals A Tunable Optical Bragg Grating Filter Based on the Droplet Sagging Effect on a Superhydrophobic Nanopillar Array

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3324
Author(s):  
Meng Zhang ◽  
Jiansheng Liu ◽  
Weifeng Cheng ◽  
Jiangtao Cheng ◽  
Zheng Zheng
Keyword(s):  
Refractive Index ◽  
Planar Waveguide ◽  
Tuning Range ◽  
Liquid Droplet ◽  
Tunable Filter ◽  
Bragg Grating ◽  
Refractive Index Sensor ◽  
Narrow Bandwidth ◽  
Simulation Results ◽  
Index Unit

Nanostructures have been widely applied on superhydrophobic surfaces for controlling the wetting states of liquid microdroplets. Many modern optic devices including sensors are also integrated with micro- or nanostructures for function enhancement. However, it is rarely reported that both microfluidics and optics are compatibly integrated in the same nanostructures. In this paper, a novel microfluidic-controlled tunable filter composed of an array of periodic micro/nanopillars on top of a planar waveguide is proposed and numerically simulated, in which the periodic pillars endow both the Bragg grating and the superhydrophobic functions. The tunability of grating is achieved by controlling the sagging depth of a liquid droplet into the periodic pillars. Simulation results show that a narrow bandwidth of 0.4 nm and a wide wavelength tuning range over 25 nm can be achieved by such a microfluidic-based tunable optofluidic waveguide Bragg grating filter. Moreover, this proposed scheme can be easily modified as a refractive index sensor with a sensitivity of 103 nm per refractive index unit.

scholarly journals ALMA's view of maser emission

2007 ◽  
Vol 3 (S242) ◽  
pp. 511-516 ◽  
Author(s):  
Alwyn Wootten
Keyword(s):  
Spectral Resolution ◽  
Tunable Filter ◽  
High Spectral Resolution ◽  
Tropical Latitude ◽  
Narrow Bandwidth ◽  
Frequency Coverage ◽  
Increased Sensitivity ◽  
Good Coverage ◽  
Complete Frequency ◽  
Compact Array

AbstractALMA, the Atacama Large Millimeter/submillimeter Array, provides a large collecting area at a location on a high dry site, endowing it with unparalleled potential for sensitive spectral line observations. Its wide frequency coverage, superb receivers and flexible backend will ensure that that potential is met. Although in the Southern Hemisphere, its tropical latitude ensures good coverage of the northern sky. Since the last meeting on astrophysical masers, the ALMA team has substantially enhanced its capability for line observations. Japan's entry into ALMA has provided increased sensitivity with the addition of the 16 antennas of the Atacama Compact Array, equivalent to eight additional 12m telescopes. The first four cartridges for the baseline ALMA receiver packages (to be augmented by three other bands owing to Japanese participation) have been accepted, with performance above the already-challenging specifications. At first light, ALMA will offer nearly complete frequency coverage of the millimeter and submillimeter spectral windows, ensuring coverage of a variety of masering transitions. ALMA's flexibility as a spectrometer has increased with the enhancement of the baseline correlator with tunable filter banks, and with the addition of a separate correlator for the ACA. As an example of the increased flexibility, ALMA is now capable of multi-spectral-region and multi-resolution modes. With the former, one might observe e.g. four separate transitions anywhere within one of four 2 GHz bands with a high resolution bandwidth. With the latter, one might simultaneously observe with low spectral resolution over a wide bandwidth and with high spectral resolution over a narrow bandwidth. Thus, one could simultaneously cover an extremely broad velocity range while providing high spectral resolution of groups of lines within that range. Several science examples will be presented illustrating ALMA's potential for transforming the millimeter and submillimeter study of masers.

Wideband Visible Wavelength Range MEMS Fabry-Perot Tunable Filter with Ag Alloy Mirror

2012 ◽  
Vol 132 (2) ◽  
pp. 25-30 ◽  
Author(s):  
Nozomu Hirokubo ◽  
Hiroshi Komatsu ◽  
Nobuaki Hashimoto ◽  
Makoto Sonehara ◽  
Toshiro Sato
Keyword(s):  
Wavelength Range ◽  
Tunable Filter ◽  
Visible Wavelength ◽  
Visible Wavelength Range ◽  
Fabry Perot

Evolution of the electronic structure of metallic multilayers from two to threedimensionality. A Full Potential Linearized Augmented Plane Wave calculation.

2002 ◽  
Vol 727 ◽  
Author(s):  
A. M. Mazzone
Keyword(s):  
Plane Wave ◽  
Density Of States ◽  
Noble Metals ◽  
Full Potential ◽  
Metallic Multilayers ◽  
Augmented Plane Wave ◽  
Narrow Bandwidth ◽  
Epitaxial Multilayers ◽  
Linearized Augmented Plane Wave ◽  
Wave Calculation

AbstractFull Potential Linearized Augmented Plane Wave calculations have been performed for epitaxial multilayers formed by the noble metals Ag and Cu with a thickness n up to 10 layers. The multilayers have a fcc lattice and are pure or compositionally modulated with a structure of the type Agn Cun or (AgCu)n. For n in the range 2,3 the density of states, evaluated at paramagnetic level, exhibits a sharp reduction of the bandwidth which is consistent with the reduced coordination of these structures. For n ≤ 5 the density of states in the central layers converges to the bulk value while the outer layers retain the narrow bandwidth found at n=2. Due to the absence of charge intermixing and hybridization, these features are shared by multilayers of all composition.

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