| 摘要 |
PROBLEM TO BE SOLVED: To obtain a square-rod excitation module, in which astigmatism and thermal birefringence of a square rod are compensated for. SOLUTION: The heat of a first square rod 41 discharge is set in y-axis direction, the heat of a second square rod 42 discharged is set in x-axis direction, a half-wave plate 43 is arranged between the rod 41 and the rod 42, and the axial direction of the plate 43 is arranged, in parallel with the y-axis direction. |
