| 摘要 |
<p>PURPOSE:To derive exactly a two-eimensional beam shape and a beam waist position by moving a knife edge consisting of two sides orthogonal to each other, in the direction orthogonal to an opxial axis of an optical beam to be measured, and measuring each moving extent of shadows of two sides of the knife edge on the photodetecting surface of the optical beam by comparing with each moving extent of two sides of this knife edge. CONSTITUTION:A knife edge 9 having two sides 10, 11 orthogonal to each other agains an optical beam 1 of a laser light is moved in the direction orthogonal to an optical axis of the optical beam 1, and a transmitting beam from its knife edge 9 is received by a photodetecting surface 3. In this case, when the knife edge moves once, a beam shape of two different directions can be known by the side 10 and 11. As a result, beam diameters of two directions can be obtained simultaneously from a moving extent of the knife edge and a variation of a transmitting light quantity of the photodetecting surface 3. When measuring a beam waist position, when the knife edge 9 is moved in the direction of the optical axis of the optical beam 1, a length of a shadow 3' of the knife edge 2 on the photodetecting surface 3 becomes minimum at a position of a beam waist, where the minimum beam diameter is obtained, therefore, it can be determined by measuring its position.</p> |
