Abstract
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.
Highlights
When the magnetic field is applied parallel to the light propagation direction, FR occurs only along the c axis
As the linear birefringence (LB) and linear dichroism (LD) values were almost identical in the presence and absence of the magnetic field (Fig. 2(a,b)), we concluded that no magnetic field was applied perpendicular to the light propagation direction
The generalized-high accuracy universal polarimeter (G-HAUP) had never been applied to a magneto-optical material
Summary
In the G-HAUP optical system, the sample was mounted on a Cu plate pinhole (diameter ~0.5 mm) to improve the signal-to-noise ratio of the transmitted light intensity. To apply the magnetic field parallel or anti-parallel to the light propagation direction, we sandwiched the mounted sample between two identical ring NIB permanent magnets (Fig. 1(b)). The G-HAUP is operated by measuring the transmitted light intensity as a function of rotations of the P and A at discrete azimuthal orientations, from which LB, LD, OR (ORP or FR) and CD can be extracted from the functional dependence of the intensity. Systematic errors; parasitic ellipticities p and q originating from imperfection of the P and A, respectively, and a small error angle δΥ attributed to the deviation from the correct crossed-Nicols configuration, are considered into the measuring theory of the G-HAUP and can be removed through the post-experimental procedures to obtain the accurate values of OR and CD. In the case where measurement of Verdet constant in isotropic direction, Verdet constant is measured by conventional optical apparatuses such as polarimeter, but here it was measured by just rotating the analyzer of the G-HAUP
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
