Tutorial 4: Solid State Phased Arrays

Author(s):  
D.G. Laighton
Keyword(s):  
Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1552
Author(s):  
Yue Wang ◽  
Yu Wang ◽  
Guohui Yang ◽  
Qingyan Li ◽  
Yu Zhang ◽  
...  

Optical phased arrays (OPAs) are essential optical elements in applications that require the ability to manipulate the light-wavefront, such as beam focusing and light steering. To miniaturize the optical components, active metasurfaces, especially graphene metasurfaces, are used as competent alternatives. However, the metasurface cannot achieve a strong resonance effect, and the function of phase control only depends on the single-layer graphene in the mid-infrared band. Here we present a graphene-metal hybrid metasurface that can generate a specific phase or a continuous sweep in the range of a 275°-based single-layer graphene structure. A key feature of our design is that the phase adjustment mainly depends on the combination mechanism of resonance intensity and frequency modulation. An all-solid-state, electrically tunable, and reflective OPA is designed by applying the bias voltage to a different pixel metasurface. The simulation results show that the maximum deflection angle of the OPA can reach 42.716°, and the angular resolution can reach 0.62°. This design can be widely applied to mid-infrared imaging, optical sensing, and optical communication systems.


2017 ◽  
Vol 42 (20) ◽  
pp. 4091 ◽  
Author(s):  
Christopher V. Poulton ◽  
Ami Yaacobi ◽  
David B. Cole ◽  
Matthew J. Byrd ◽  
Manan Raval ◽  
...  

Author(s):  
T. J. Magee ◽  
J. Peng ◽  
J. Bean

Cadmium telluride has become increasingly important in a number of technological applications, particularly in the area of laser-optical components and solid state devices, Microstructural characterizations of the material have in the past been somewhat limited because of the lack of suitable sample preparation and thinning techniques. Utilizing a modified jet thinning apparatus and a potassium dichromate-sulfuric acid thinning solution, a procedure has now been developed for obtaining thin contamination-free samples for TEM examination.


Author(s):  
Kenneth M. Richter ◽  
John A. Schilling

The structural unit of solid state collagen complexes has been reported by Porter and Vanamee via EM and by Cowan, North and Randall via x-ray diffraction to be an ellipsoidal unit of 210-270 A. length by 50-100 A. diameter. It subsequently was independently demonstrated by us in dog tendon, dermis, and induced complexes. Its detailed morphologic, dimensional and molecular weight (MW) aspects have now been determined. It is pear-shaped in long profile with m diameters of 57 and 108 A. and m length of 263 A. (Fig. 1, tendon, KMnO4 fixation, Na-tungstate; Fig. 2a, schematic of unit in long, C, and x-sectional profiles of its thin, xB, and bulbous, xA portions; Fig. 2b, tendon essentially unmodified by ether and 0.4 N NaOH treatment, Na-tungstate). The unit consists of a uniquely coild cable, c, of ṁ 22.9 A. diameter and length of 2580-3316 A. The cable consists of three 2nd-strands, s, each of m 10.6 A.


Author(s):  
Linda C. Sawyer

Recent liquid crystalline polymer (LCP) research has sought to define structure-property relationships of these complex new materials. The two major types of LCPs, thermotropic and lyotropic LCPs, both exhibit effects of process history on the microstructure frozen into the solid state. The high mechanical anisotropy of the molecules favors formation of complex structures. Microscopy has been used to develop an understanding of these microstructures and to describe them in a fundamental structural model. Preparation methods used include microtomy, etching, fracture and sonication for study by optical and electron microscopy techniques, which have been described for polymers. The model accounts for the macrostructures and microstructures observed in highly oriented fibers and films.Rod-like liquid crystalline polymers produce oriented materials because they have extended chain structures in the solid state. These polymers have found application as high modulus fibers and films with unique properties due to the formation of ordered solutions (lyotropic) or melts (thermotropic) which transform easily into highly oriented, extended chain structures in the solid state.


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