| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a low-cost and compact optical spectrum analyzer capable of measuring, with high resolution, the intensity of each set of orthogonal polarized lights of incident light. <P>SOLUTION: In an optical spectrum analyzer, light Px to be measured is make into parallel light by a first lens 22 and directed to a polarized light separating part 23 to separate orthogonal polarized light elements. Then, the polarization direction of one of the separated light elements is turned 90 degrees by a half wavelength plate 24 so as to be matched with that of the other separated light element, and directed to a diffraction grating 30 of a wavelength selecting part 29. A single second lens 40 is used both as a lens for focusing each of the polarized light elements each and directing the elements to polarized light preserving optical fibers 41 and 42 and as a lens for changing each of the polarized light elements returned by the polarized light preserving optical fibers 41 and 42 into parallel beams and directing the beams to the diffraction grating 30 again. Further, selected lights of final order (the fourth-order selected lights in this example) are focused by third and fourth lenses 45 and 46, directed to pass through slits 47 and 48, and received by optical receivers 50 and 51. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
