NONLINEAR REFRACTION AND INCREASING ABSORPTION IN HgCdTe OPTICAL BISTABILITY AT ROOM TEMPERATURE : AN EXPERIMENTAL STUDY

1988 ◽  
Vol 49 (C2) ◽  
pp. C2-135-C2-136
Author(s):  
S. CECCHI ◽  
P. M. COPPO ◽  
P. SALIERI ◽  
F. T. ARECCHI
Keyword(s):  
Experimental Study ◽  
Optical Bistability ◽  
Room Temperature ◽  
Nonlinear Refraction

scholarly journals Composite Material of PDMS with Interchangeable Transmittance: Study of Optical, Mechanical Properties and Wettability

2021 ◽  
Vol 5 (4) ◽  
pp. 110
Author(s):  
Flaminio Sales ◽  
Andrews Souza ◽  
Ronaldo Ariati ◽  
Verônica Noronha ◽  
Elder Giovanetti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Room Temperature ◽  
Casting Process ◽  
Optical Characteristics ◽  
Smart Devices ◽  
Superhydrophobic Coating ◽  
Gravity Casting ◽  
High Flexibility ◽  
Physical And Chemical

Polydimethylsiloxane (PDMS) is a polymer that has attracted the attention of researchers due to its unique properties such as transparency, biocompatibility, high flexibility, and physical and chemical stability. In addition, PDMS modification and combination with other materials can expand its range of applications. For instance, the ability to perform superhydrophobic coating allows for the manufacture of lenses. However, many of these processes are complex and expensive. One of the most promising modifications, which consists of the development of an interchangeable coating, capable of changing its optical characteristics according to some stimuli, has been underexplored. Thus, we report an experimental study of the mechanical and optical properties and wettability of pure PDMS and of two PDMS composites with the addition of 1% paraffin or beeswax using a gravity casting process. The composites’ tensile strength and hardness were lower when compared with pure PDMS. However, the contact angle was increased, reaching the highest values when using the paraffin additive. Additionally, these composites have shown interesting results for the spectrophotometry tests, i.e., the material changed its optical characteristics when heated, going from opaque at room temperature to transparent, with transmittance around 75%, at 70 °C. As a result, these materials have great potential for use in smart devices, such as sensors, due to its ability to change its transparency at high temperatures.

An experimental study of the reactivity of the hydroxide anion in the gas phase at room temperature, and its perturbation by hydration

1981 ◽  
Vol 59 (11) ◽  
pp. 1615-1621 ◽  
Author(s):  
Scott D. Tanner ◽  
Gervase I. Mackay ◽  
Diethard K. Bohme
Keyword(s):  
Experimental Study ◽  
Proton Transfer ◽  
Gas Phase ◽  
Rate Constants ◽  
Room Temperature ◽  
Gas Phase Reactions ◽  
Flowing Afterglow ◽  
Hydroxide Anion

Flowing afterglow measurements are reported which provide rate constants and product identifications at 298 ± 2 K for the gas-phase reactions of OH− with CH3OH, C2H5OH, CH3OCH3, CH2O, CH3CHO, CH3COCH3, CH2CO, HCOOH, HCOOCH3, CH2=C=CH2, CH3—C≡CH, and C6H5CH3. The main channels observed were proton transfer and solvation of the OH−. Hydration with one molecule of H2O was observed either to reduce the rate slightly and lead to products which are the hydrated analogues of the "nude" reaction, or to stop the reaction completely, k ≤ 10−12 cm3 molecule−1 s−1. The reaction of OH−•H2O with CH3—C≡CH showed an uncertain intermediate behaviour.

Optical bistable switching in pyran dye-doped polymers

2014 ◽  
Vol 23 (02) ◽  
pp. 1450018 ◽  
Author(s):  
Purnima ◽  
Devendra Mohan
Keyword(s):  
Solid State ◽  
Communication Systems ◽  
Optical Bistability ◽  
Nonlinear Refraction ◽  
Nonlinear Behavior ◽  
Single Mode ◽  
Third Order ◽  
Bistable Switching ◽  
Fabry Perot ◽  
Doped Polymers

In the present frame of work, optical bistability using a Fabry–Perot (FP) cavity containing 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM) dye entrapped in poly-methylmethacrylate (PMMA) matrix is experimentally investigated. Optical nonlinear behavior of solid-state samples is studied using a single-mode Q-switched nanosecond Nd:YAG laser operating at 532 nm. Various optical nonlinear parameters such as nonlinear refractive index (n2) and third-order susceptibility (χ3) of the material are numerically estimated from bistability loops. The origin of optically bistable behavior is attributed to photoisomerization-assisted nonlinear refraction phenomenon. It is observed that nonlinear refraction dominates over nonlinear absorption in giving rise to the optical bistability. The study shows that DCM dye entrapped in solid-state matrices are promising candidate for polymer-based optical switches, data processing, and communication systems.

EXPERIMENTAL STUDY ON DURABILITY OF ROOM TEMPERATURE CURING UFC MORTAR

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Haruka Murakami ◽  
Hiromi Fujiwara ◽  
Masanori Maruoka ◽  
Takahumi Watanabe ◽  
Koji Satori
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
High Performance ◽  
Room Temperature ◽  
Bending Strength ◽  
High Performance Concrete ◽  
Drying Shrinkage ◽  
Concrete Repair ◽  
Repair Materials ◽  
Low Salt

In recent years, as structures become higher, larger, and more durable concrete whose compressive strength of the concrete is 150 N/mm 2 or more have been put to practical use. It is for this reason that it is necessary to develop strengthening materials with equal or better performance. Furthermore, the development of high-performance concrete repair materials is carried out because demand to seismic strengthening and repair increases. In this study, considering these circumstances, it was conducted an experimental study with the aim of developing a repair material using room temperature curing UFC (R-UFC). A binder composition preparation of the R-UFC has excellent fluidity under pressure. It was achieved that high-grade thixotropy, high compressive strength, and high bending strength. It can also be sprayed continuously because of its high thixtoropy. It was confirmed that the sprayed thickness was reached to 20mm by one work. Durability of this R-UFC was investigated and it was confirmed the high sulfate resistance, small drying shrinkage and low salt permeability.

Theory of nonlinear refraction near the band edge of a semiconductor

1982 ◽  
Vol 379 (1776) ◽  
pp. 67-90 ◽  
Keyword(s):  
Absorption Edge ◽  
Optical Bistability ◽  
Nonlinear Refraction ◽  
Four Wave Mixing ◽  
Band Edge ◽  
Wave Mixing ◽  
Nonlinear Dispersion ◽  
Physical Origin ◽  
Differential Gain

Detailed comparisons are made of the results of two approaches to the problem of nonlinear refraction at frequencies just below the band edge in semiconductors. The physical origin o f the nonlinear dispersion is taken to be direct saturation of independent, T 2 -broadened band states in the first model discussed. In the second model the refraction associated with a dynamic Burstein-Moss shift of the absorption edge is considered. Both models predict an extremely large nonlinearity, X (3) ≈ 1 e. s. u., of importance in the field of dispersive optical bistability and consistent with experimental observations of bistability, two-beam differential gain and four-wave mixing.

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