A Simple Graphic Method for Analyzing the Polarization State of an Optical System With a Fixed Polarizer and a Rotating Elliptical Retarder

Abstract

The trajectory of the polarization state of a monochromatic beam passing through a fixed linear polarizer and a rotating elliptical retarder on the Poincaré sphere is found to be a threedimensional 8-shaped contour, which is determined as the line of intersection of a right-circular cylinder with the Poincaré sphere. The cylinder is parallel to the S 3 axis, and the projection of the contour on the S 1 S 2 plane is a circle whose center and radius are determined. A method of projecting the three-dimensional geometric relationships to the two-dimensional S 1 S 2 plane to locate the position of the polarization state of the emerging beam on the Poincaré sphere for a given azimuth of the elliptical retarder is presented, and applied to solve a problem of polarization optics. The proposed graphic method substantially simplifies the polarization state analysis involving elliptical retarders.

Advances in Synthesis Strategies for Lanthanide-based NaYF4 Upconversion Nanocrystals and Their Applications in Ratiometric Thermometry

“…Among several optical parameters, including emission intensity, spectrum shape, fluorescence lifetime, bandwidth, and spectral shift, Fluorescence Intensity Ratio (FIR) stands out as the most accurate and reliable optical parameter for temperature monitoring due to its remarkable ability to prevent self-referencing [84][85][86][87]. FIR-based upconversion nano-thermometry could also be applied in various fields, including anti-counterfeiting [88], optical rotation [89,90], nonlinear properties [91,92], temperature-controlled integrated circuit devices [93][94][95], temperature-sensitive cancer or antibiotic therapies [96,97] and temperature calibration for gas sensing [98]. Nanoparticle ensembles have been prevalent in most temperature measurements based on upconversion nanoparticles [99][100][101].…”