Title:
ENERGY MEASUREMENT METHOD FOR PULSE LASER BEAM AND MEASUREMENT DEVICE THEREFOR
Document Type and Number:
Japanese Patent JPH0493625
Kind Code:
A
Abstract:
PURPOSE:To enable the energy of a laser beam of high repetitive frequencies with short pulses and low energy to be measured by inversely operating the aforesaid energy from a correlation obtained from the concurrent measurement of the energy with a Joule meter and a photodiode. CONSTITUTION:A Joule meter 3 is inserted in space between DUT (measured sample) 4 and a beam divider 2, and the maximum voltage of the meter 3 and a photodiode 5 is assumed to be Vj and Vl respectively, when one pulse of a pulse laser beam source 1 is irradiated. In this case, pulse energy Ej is expressed as Ej=Vj.Kj, where Kj is a calibration factor for the meter 3 for energy and maximum voltage. Also, a ratio of Ej to the maximum voltage Vl of the photodiode 5 is used as a correlation factor K. The meter 3 is removed from a light path and a pulse laser beam is irradiated to DUT 4. Then, the maximum voltage Vn of the photodiode 3 is measured at every pulse. As a result, the laser energy En of each pulse is given as En=Vn.K.
Inventors:
UEKI TAKEMI
Application Number:
JP20526190A
Publication Date:
March 26, 1992
Filing Date:
August 03, 1990
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE
International Classes:
G01J1/42; G01J11/00; (IPC1-7): G01J1/42; G01J11/00
Attorney, Agent or Firm:
Akihide Sugimura (1 outside)