<P> Optical rotation or optical activity (sometimes referred to as rotary polarization) is the rotation of the plane of polarization of linearly polarized light as it travels through certain materials . Optical activity occurs only in chiral materials, those lacking microscopic mirror symmetry . Unlike other sources of birefringence which alter a beam's state of polarization, optical activity can be observed in fluids . This can include gases or solutions of chiral molecules such as sugars, molecules with helical secondary structure such as some proteins, and also chiral liquid crystals . It can also be observed in chiral solids such as certain crystals with a rotation between adjacent crystal planes (such as quartz) or metamaterials . Rotation of light's plane of polarization may also occur through the Faraday effect which involves a static magnetic field, however this is a distinct phenomenon that is not usually classified under "optical activity ." </P> <P> The rotation of the plane of polarization may be either clockwise, to the right (dextrorotary--d - rotary), or left (levorotary--l - rotary) depending on which stereoisomer is present (or dominant). For instance, sucrose and camphor are d - rotary whereas cholesterol is l - rotary . For a given substance, the angle by which the polarization of light of a specified wavelength is rotated is proportional to the path length through the material and (for a solution) proportional to its concentration . The rotation is not dependent on the direction of propagation, unlike the Faraday effect where the rotation is dependent on the relative direction of the applied magnetic field . </P> <P> Optical activity is measured using a polarized source and polarimeter . This is a tool particularly used in the sugar industry to measure the sugar concentration of syrup, and generally in chemistry to measure the concentration or enantiomeric ratio of chiral molecules in solution . Modulation of a liquid crystal's optical activity, viewed between two sheet polarizers, is the principle of operation of liquid - crystal displays (used in most modern televisions and computer monitors). </P> <P> The rotation of the orientation of linearly polarized light was first observed in 1811 in quartz by French physicist François Jean Dominique Arago . In 1820, the English astronomer Sir John F.W. Herschel discovered that different individual quartz crystals, whose crystalline structures are mirror images of each other (see illustration), rotate linear polarization by equal amounts but in opposite directions . Jean Baptiste Biot also observed the rotation of the axis of polarization in certain liquids and vapors of organic substances such as turpentine . Simple polarimeters have been used since this time to measure the concentrations of simple sugars, such as glucose, in solution . In fact one name for D - glucose (the biological isomer), is dextrose, referring to the fact that it causes linearly polarized light to rotate to the right or dexter side . In a similar manner, levulose, more commonly known as fructose, causes the plane of polarization to rotate to the left . Fructose is even more strongly levorotatory than glucose is dextrorotatory . Invert sugar syrup, commercially formed by the hydrolysis of sucrose syrup to a mixture of the component simple sugars, fructose, and glucose, gets its name from the fact that the conversion causes the direction of rotation to "invert" from right to left . </P>

Does the following isomer rotate plane polarized light