OPERATIONAxiolab 5 Illumination and contrast methods in transmitted light ZEISS05/2019 430037-7444-001 914.2.4.2 Determination of the polarization direction nγ’(1) ApplicationThe determination of the polarization direction of nγ or nγ' respectively (polarization direction with theabsolute or relative largest index of refraction) and nα or nα' respectively (polarization direction with theabsolute or relative smallest index of refraction) relative to the morphological directions, e.g. of crystalsurfaces, crystal needles or fibers, provide an important signature of the material. This method is alsoused in the diagnosis of bio-crystals (e.g. gout and pseudo-gout).Fig. 4-8 Determining the polarization direction nγ' using a synthetic fiber as an example(2) Instrumentation− Eyepiece with crossline reticle− Strain-free objectives− Pol rotary stage (Fig. 4-7/1)− Polarizer D (rotatable or fixed)− Screw-in fixed analyzer slider D or lambda compensator or lambda/4 compensator combined withanalyzer (in Axiolab 5 tubes)− Pol adjustment tool sample for polarization microscope (453679-0000-000)(3) Configuring the microscope• Adjust the microscope as described in section 4.2.1 (3) for transmitted light brightfield microscopy.Make sure the inter-pupillary distance is adjusted correctly on the binocular tube (see section 4.1.1).• Center the Pol rotary stage (Fig. 4-7/1) and objectives (see sections 3.1.7.5 and 3.1.7.6).• Swivel the polarizer (Fig. 4-7/3) into the beam path and, if it is rotatable, position it at 0°.• Insert the analyzer slider (Fig. 4-7/2) into the slot for compensators or in the intermediate plate (if tubedoes not already have an analyzer). The field of view will appear dark due to the crossed polarizers. Ifnot, align the analyzer in the tube or the intermediate plate.• Place the Pol adjustment tool sample on the microscope stage and rotate it until the sample appearsdark.
