Optical properties of superconducting Bi2Sr2CaCu2O8

Polarimetric studies of L-arginine-doped potassium dihydrogen phosphate single crystals

Conoscopic interference patterns, channelled spectra and polarimetric techniques have been used for the characterization of pure and doped (with L-arginine amino acid) potassium dihydrogen phosphate (KDP) single crystals. Experimental polarimetric data have been obtained for the frequently used wavelength of 633 nm and for two close wavelengths of 532 and 543 nm in a high-accuracy dual-wavelength polarimeter. The measurement of eigenwave ellipticity in the [100] and [010] directions and between 295 and 340 K shows small differences in the absolute values of the specific optical rotations of KDP crystals doped with L-arginine in the range of 0.7–3.8 wt%. It is found that the gyration tensor component g 11, specific optical rotation and eigenwave ellipticity show different dispersion in the visible spectral region.

Determination of the Faraday rotation perpendicular to the optical axis in uniaxial CeF3 crystal by using the Generalized-High Accuracy Universal Polarimeter

Many single crystals have been developed and commercialized for optical isolators. However, optical isolator materials have been limited to isotropic crystals or to the isotropic direction (optic axis) of anisotropic crystals. This study investigates the wavelength dependences of linear birefringence, linear dichroism, Faraday rotation and magnetic-circular dichroism in a single crystal rare-earth fluoride, namely CeF₃. Measurements were made in the direction parallel and perpendicular to the optic axis under an applied magnetic field. The magnetic field was generated by Nd-Fe-B magnets installed in the generalized-high accuracy universal polarimeter (G-HAUP). The first application of G-HAUP to a magneto-optical material is presented. In the CeF₃ crystal, the Verdet constants along directions parallel and perpendicular to the optic axis were positive over the measured wavelength region (300-680 nm), and their magnitudes were nearly equal. The success in the accurate measurement on Faraday rotation along anisotropic directions has opened the way to study on optical isolators along the direction other than optic axis.

Application of two-dimensional intensity maps in high-accuracy polarimetry

We propose the analysis of 2D intensity contour maps which is based on the optical transmission function for the polarizer-specimen-analyzer system. A small modification of the high-accuracy universal polarimeter (HAUP) technique was used to measure the intensity maps (HAUP maps) and determine the phase retardation, linear dichroism (LD) parameters, and multiple light reflection contribution in uniaxial crystals. We have performed measurements in a direction perpendicular to the optical axis on pure birefringent LiNbO₃, birefringent optically active SiO₂, and two birefringent optically active dichroic galogermanate crystals doped with Mn³⁺ and Cr³⁺ ions. We have obtained good agreement of the experimental data for 532, 633, and 650 nm wavelengths with analytical values. These results extend the capabilities of high-accuracy polarimetry to anisotropic crystal studies.

Extraction of effective parameters of anisotropic optical materials using a decoupled analytical method

A decoupled analytical technique based on the Mueller matrix method and the Stokes parameters is proposed for extracting effective parameters of anisotropic optical materials in linear birefringence (LB), linear dichroism (LD), circular birefrinegence (CB), and circular dichroism (CD) properties. This technique is essential in determining the optical properties of opto-electric or biomedical materials for the development of advanced inspection and/or diagnostic applications. The error and resolution analysis of the proposed approach is demonstrated by extracting the effective parameters given an assumption of errors ranging ± 0.005 in the values of the output Stokes parameters. The results confirm the ability of the proposed method to yield full-range measurements of all the optical parameters. The decoupled nature of the analytical model yields several important advantages, including an improved accuracy and the ability to extract the parameters of optical samples with only LB, CB, LD, or CD property without using compensation technique or pretreatment. Moreover, by decoupling the extraction process, the "multiple solutions" problem inherent in previous models presented by the current group is avoided.

Measurement of circular birefringence and circular dichroism of the single crystals of lambda-(+)589- and delta-(-)589-tris(ethylenediamine)cobalt(III) triiodide monohydrate by the extended HAUP method

We have achieved measuring four optical parameters simultaneously, namely, linear birefringence (LB), circular birefringence (CB), linear dichroism (LD), and circular dichroism (CD), of single crystals of Lambda-(+)(589)- and Delta-(-)(589)-tris(ethylenediamine) cobalt(III) triiodide monohydrate (1) along the <001> plane at the fixed wavelength (514.5 nm). Such measurements are possible only when the High Accuracy Universal Polarimeter (HAUP) is employed; it is called the extended HAUP method. Our experimental results showed that both LB and LD of the Lambda-(+)(589)-(1) crystal have the same magnitude as those of the Delta-(-)(589)-(1) crystal. It was also revealed for the first time that the CB data of crystals of Lambda-(+)(589)-(1) and Delta-(-)(589)-(1) are almost of the same magnitude, but are of opposite sign, reflecting their opposite absolute configurations. On the other hand, although the CD data obtained for Lambda-(+)(589)-(1) is almost three times larger than that for Delta-(-)(589)-(1,) these CD data are also opposite in sign, as expected from the opposite chirality of crystals. .