Time-Resolved Profiles in Modulated Polarization Spectroscopy
The absorption of a modulated light beam in which the state of the polarization is continuously variable is discussed. It is now possible to measure the average time-dependent profile for the polarization cycle of such a beam, and corresponding theoretical descriptions are needed in order to extract the information contained in it. This work generates such a description. Based on a semiclassical treatment of light/matter interactions, a three-parameter fit function is derived that permits the simultaneous extraction of absorbance, linear dichroism, and circular dischroism from the profile for various types of uniformly oriented, partially oriented, and isotropic materials and combinations of them. The theoretical expressions are used to analyze data for (+)-3-methylcyclopentanone, the results being (1) an increase of the S/N ratio, (2) the simultaneous generation of absorption and dichroism spectra of identical quality, and (3) a description of window adsorbates of the cyclopentanone material. The Jones p...
Natural and Magnetic Vacuum Ultraviolet Circular Dichroism Measurements at the Synchrotron Radiation Center University of Wisconsin-Madison
Substances which rotate the plane of polarization of linearly polarized light are called optically active. The optical rotation occurs due to unequal responses to left and right circularly polarized radiation. Circular dichroism spectroscopy measures the difference in absorption between left and right circularly polarized light (usually expressed as the difference in molar extinction coefficient, eL-eR, or absorbance, AL-AR) as a function of wavelength.
Application design of a sun-tracking system
As a very good renewable energy, solar energy gets a lot of countries' concerns. How to improve the efficiency of solar panel is now a hot topic and sun tracking is one of the solutions. In this paper, a servo tracking system using dSPACE DS1104 R&D controller board is designed to improve solar collection efficiency. It combines electro-optical tracking and sun trajectory tracking, and can keep solar panels perpendicular to the sun during daylight hours. In order to reduce the amount of computation, a T-S fuzzy system based sun trajectory tracking is proposed. Because of the seamless connection between dSPACE and MATLAB/Simulink, the development cycle time is short. Experimental results show that the system can track the sun precisely and has higher efficiency.