فهرست مطالب azadeh ahmadian

In this research, we investigate and compare the optical properties of lead borate and bismuth borate glasses. We used the Refractive index and the energy band gaps determined experimentally in Ref [22]. We found that molar refraction and electronic polarizability demonstrate similar behavior. The metallization varies from 0.630 to 0.568 for lead borate glasses and from 0.526 to 0.435 for bismuth borate glasses with increasing PbO/Bi2O3 content. The transmission coefficient decreased from 0.884 to 0.846 for PbB glasses and from 0.818 to 0.751 for BiB glasses, while the dielectric constant increased from 2.755 to 3.276 for PbB glasses and from 3.094 to 4.884 for BiB glasses. The optical electronegativity decreased from 0.964 to 0.792 for PbB and from 0.857 to 0.760 for BiB. The linear dielectric susceptibility increased from 0.139 to 0.181 for lead borate glasses and from 0.214 to 0.309 for bismuth borate glasses. The nonlinear optical susceptibility changed from 0.647  to 1.829  esu for PbB and from 0.359  to 1.551  esu for BiB , indicating more than fivefold increment. The nonlinear refraction index varied from 1.470  to 3.810  esu for lead borate glasses and from 0.704  to 2.646  esu for bismuth borate glasses. The results confirm that bismuth borate is better than lead borate for optical applications.

This study evaluated the light transmission characteristics of a single modular fiber with a cylindrical microchannel using the FDTD method. To this end, various microchannel diameters (4-11μm) were explored. The SMF included a silica core (n=1.4) coated by a nanodiamond layer with a refractive index of 2.42. The impact of Fabry-Perot resonance was evidently detected in transmission features. At constant , the light transmission variations depended on the refractive index of the microchannel. A significant change was observed in the upon altering the microchannel refractive index. Based on the results, a microchannel-based SMF with different diameters can be employed for refractive index sensing. In the cases where the diameter of the microchannel largely differs from that of the core (8μm), the transmission variations were negligible. The numerical results are in good agreement with those reported in the microhole or microchannel experiment. The highest and lowest transmissions were recorded for the microchannel at diameters of 4 and 11μm, respectively. Comparing related experimental and numerical results show proper control of the microchannel diameter can enhance light transmission through the core-microchannel. The sensitivity of the refractive index to the microchannel diameter is a promising feature that can be exploited for developing various fiber optical devices.