Large nonresonant light-induced refractive-index changes in thin films of amorphous arsenic sulfide

1991 ◽  
Vol 16 (7) ◽  
pp. 458 ◽  
Author(s):  
E. M. True ◽  
L. McCaughan
Author(s):  
Andrei M. Andriesh ◽  
Francesco Michelotti ◽  
Valentin N. Ciumash ◽  
Mario Bertolotti

1993 ◽  
Author(s):  
Francesco Michelotti ◽  
Mario Bertolotti ◽  
Valentin N. Ciumash ◽  
Andrei M. Andriesh

2003 ◽  
Vol 795 ◽  
Author(s):  
Lianchao Sun ◽  
Ping Hou

ABSTRACTControl of the film stress and optical property has long been considered as an issue in the tunable optical MEMS (Micro-Electro-Mechanical Systems) devices. In this paper, the atmospheric evolution of Titanium Dioxide (TiO2) and Silicon Dioxide (SiO2) thin films for the optical MEMS devices were studied. These films were prepared by ion-assisted e-beam evaporation. It is found that as-deposited SiO2 films exhibit compressive stress; whereas, it is tensile in the TiO2 films under present processing conditions. When annealed at 150 °C, both SiO2 and TiO2 films show slight changes in stress with annealing time. However, increasing the anneal temperature to 250°C caused an apparent change of film stresses with time, in which SiO2 film turns into less compressive and TiO2 film appears to be more tensile. The optical properties after annealing were also investigated by measuring the thickness and the refractive index changes using the spectroscopic ellipsometry technique. At both experimental temperatures, the film thickness increases slightly and the refractive index at 1550 nm decreases a little at the initial annealing stage for SiO2 films. For TiO2 films, it is found that the refractive index increases after annealing at 250°C. This might be caused by the TiO2 film densification process during amorphous-to-crystalline phase transformation. Because most of the significant film evolutions occur during the initial 12 hours of annealing, a practical way of stabilizing the film properties in a MEMS device is to pre-anneal the as-deposited thin films.


2003 ◽  
Vol 137 (1-3) ◽  
pp. 1405-1406 ◽  
Author(s):  
S. Miura ◽  
A. Kobayashi ◽  
H. Naito ◽  
Y. Matsuura ◽  
K. Matsukawa ◽  
...  

2003 ◽  
Author(s):  
Bradley F. Chmelka ◽  
Earl Danielson ◽  
Michael D. Wyrsta

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 112
Author(s):  
Qais M. Al-Bataineh ◽  
Mahmoud Telfah ◽  
Ahmad A. Ahmad ◽  
Ahmad M. Alsaad ◽  
Issam A. Qattan ◽  
...  

We report the synthesis and characterization of pure ZnO, pure CeO2, and ZnO:CeO2 mixed oxide thin films dip-coated on glass substrates using a sol-gel technique. The structural properties of as-prepared thin film are investigated using the XRD technique. In particular, pure ZnO thin film is found to exhibit a hexagonal structure, while pure CeO2 thin film is found to exhibit a fluorite cubic structure. The diffraction patterns also show the formation of mixed oxide materials containing well-dispersed phases of semi-crystalline nature from both constituent oxides. Furthermore, optical properties of thin films are investigated by performing UV–Vis spectrophotometer measurements. In the visible region, transmittance of all investigated thin films attains values as high as 85%. Moreover, refractive index of pure ZnO film was found to exhibit values ranging between 1.57 and 1.85 while for CeO2 thin film, it exhibits values ranging between 1.73 and 2.25 as the wavelength of incident light decreases from 700 nm to 400 nm. Remarkably, refractive index of ZnO:CeO2 mixed oxide-thin films are tuned by controlling the concentration of CeO2 properly. Mixed oxide-thin films of controllable refractive indices constitute an important class of smart functional materials. We have also investigated the optoelectronic and dispersion properties of ZnO:CeO2 mixed oxide-thin films by employing well-established classical models. The melodramatic boost of optical and optoelectronic properties of ZnO:CeO2 mixed oxide thin films establish a strong ground to modify these properties in a skillful manner enabling their use as key potential candidates for the fabrication of scaled optoelectronic devices and thin film transistors.


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