In this paper, we propose and experimentally demonstrate a compact optical fiber sensor based on a Mach-Zehnder interferometer (MZI) cascaded with fiber Bragg grating (FBG) for simultaneous measurement of refractive index (RI) and temperature. In order to
Focusing properties of Gaussian beam induced by nonspiral and spiral phase plates are investigated numerically. The nonspiral phase plate introduces phase singularity to the incident beam, and the spiral one adjusts the radial phase distribution. Intensit