| 摘要 |
<p>Optical parameters of a substance, including absorbancy, transmittency, turbidity and scattering coefficients, circular and linear birefringency, and circular and linear dichroism, are computed from phase or modulation coefficient measurements. Monochromatic light obtained from a source (1) and monochromator (2) is linearly polarized by a polarizer (P) such that its polarization vector rotates at a definite frequency without affecting its intensity. The resulting beam is then directed at a sample station (6) and processed as necessary using a polarizing analyzer or quarter-wave plate, and the beam emerging from the sample station is focussed on a photodector (8) by focusing means (7), to generate an electrical output signal therein. The signal is fed to a phasemeter (16) or modulation coefficient detector (17) each coupled to a computer (18) and may be compared with reference signals obtained from a reference beam derived from the linearly polarized light emerging from the polarizer (P). Dichroism values are determined from modulation coefficient measurements and values of the other parameters noted above are obtained from relative phase measurements.</p> |
