Three-dimensional ordered structure of metal-organic frameworks (MOFs) optical gas sensor was successfully prepared by vertical deposition method. This sensor was built to detect carbon tetrachloride (CCl4) gas. When exposed to carbon tetrachloride gas, the sensing system can clearly detect the drift of the peak of its reflection spectrum. The gas sensor showed the good characteristics of stability and strong anti-interference ability. Moreover, it was found that the concentration of measuring CCl4 gas is a linear relationship with the optical signal of the sensitive element. The results of measuring CCl4 gas demonstrated that the sensor has a high sensitivity for CCl4 gas with a fast response about 2 second, therefore it takes advantages of high sensitivity and simple structure.
A light intensity distribution generated by an electro-optic tunable multiphase array based on the Talbot effect under lower external electric field was demonstrated. This 2-D distribution is mapped as a 2D hexagonal tunable phase array based on the periodically poled MgO-doped LiNbO3 crystal (PPMgLN). Applying a lower external electric field through the Indium Tin Oxide (ITO) electrodes coated on the +z and –z surfaces of PPMgLN crystal, a tunable PTAI was fabricated. The self-imaging phenomenon of Talbot effect in the Fresnel field for this phase array coherently illuminated is theoretically analyzed according to Fresnel diffraction theory. The experimental and theoretical results show that the self-images visibility depends on array duty cycle and external electric field for a fixed diffraction distance. The optimal self-images visibility can be obtained at array duty cycle of 52%, phase difference of 0.75π for diffraction position of 0.33 times Talbot distance. Moreover, a preferable self-image pattern can be observed under an unprecedented lowest external voltage of 0.461kV correspond to phase difference of 0.35π,which is beneficial to optical integration and micro optical devices.
Electro-optically tunable two-dimensional hexagonal Talbot phase array which are based on congruent Lithium
Niobate crystal and MgO doped Lithium Niobate crystals are investigated, respectively. Experimental results show that a
variety of pattern can be generated under different voltage bias and fractional distance. Numerical simulation was studied,
and the experimental results agreed with simulation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.