Active long pulse shaping technique of pulsed CO 2 laser using multi-pulse discharge control

• Published in: Optics and laser technology 2004-02, Vol.36 (1), p.57-61
• Main Authors: Lee, Yu-Soo, Chung, Hyun-Ju, Joung, Jong-Han, Kim, Eung-Jo, Kim, Hee-Je
• Format: Article
• Language: English
• Subjects: Laser pulse shape; Multi-pulse superposition; Power supply; Pulse forming network (PFN); Pulsed CO 2 laser
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/S0030-3992(03)00133-6

We describe the pulse forming of pulsed CO 2 laser using multi-pulse superposition technique. Various pulse shapes, high duty cycle pulse forming network (PFN) are constructed by time sequence. This study shows a technology that makes it possible to make various long pulse shapes by activating SCRs of three PFN modules consecutively at a desirable delay time with the aid of a PIC one-chip microprocessor. The power supply for this experiment consists of three PFN modules. Each PFN module uses a capacitor, a pulse forming inductor, a SCR, a high voltage pulse transformer, and a bridge rectifier on each transformer secondary. The PFN modules operate at low voltage by driving the primary of HV pulse transformer. The secondary of the transformer has a full-wave rectifier, which passes the pulse energy to the load in a continuous sequence. We investigated various long pulse shapes as different trigger time intervals of SCRs among three PFN modules. As a result, we could obtain laser beam with various pulse shapes and durations from about 250 to 1000 μs .