| 摘要 |
PURPOSE:To measure instantaneously and easily an energy distribution by providing a photodetecting surface on the surface of a circular substrate having a thermal conductivity, providing a ring-shaped heat sensitive element group in a shape of a concentric circle on the reverse side, and fetching a differential output of each heat sensitive element. CONSTITUTION:A photodetecting surface 7 for absorbing a laser beam 6 is provided on the surface of a circular substrate 5 having a high thermal conductivity such as alumina ceramic. Also, on the reverse side of this circular substrate 5, three pieces or more of ring-shaped heat sensitive elements 8 are provided in a shape of a concentric circle by spattering a thermist material of SiC, etc., and thereafter, burning it. Also, one terminal of these heat sensitive elements 8 is terminated by a minus electrode 9, the other end is connected to a plus electrode 10 of a differential amplifying circuit 11, and an output of the adjacent heat sensitive element 8 is brought to a differential amplification and fetched. In this way, an energy distribution of a laser beam being a circular Gaussian beam can be measured. |
