WAVELENGTH PLATE MEASURING INSTRUMENT

摘要

PURPOSE:To make possible the measurement of the phase-shifting efficiency of a wavelength plate simply and easily by a method wherein a plurality of reflectors are used to make parallel luminous flux pass through a 1/4 wavelength plate twice via different axes. CONSTITUTION:Luminous flux which has passed through a 1/4 wavelength plate 8 enters a reflector 4 and passes through a lens 43. The flux is reflected on the surface of a reflector 45 and allowed to again pass through the lens 43 to become reflective flux along an optical axis 50 in parallel with an optical axis 9. The flux is then made to enter a reflective prism device 6 of a reflector 5 and pass through a polaroid prism 58 before entering a detector 7. The second polaroid prism 6 is rotated to divide the luminous flux supplied to the detector 7 into a P polarized light component and an S polarized light component. From the output values of both the components, the characteristics of the 1/4 wavelength plate can be obtained according to the preselected equation. Thus it is possible to measure the phase-shifting efficiency of the wavelength plate simply and easily.