Title :
A simple pulsed CO2 laser with long pulse duration of millisecond order
Author :
Chung, Hyun-Ju ; Lee, Dong-Hoon ; Joung, Jong-Han ; Park, Sung-Joon ; Lee, Yu-Soo ; Kim, Hee-Je
Author_Institution :
Dept. of Electr. Eng., Pusan Nat. Univ., South Korea
Abstract :
We demonstrate a simple pulsed CO2 laser with long pulse duration of millisecond order at low pressure less than 30 Torr. A new power supply for our laser system switches the voltage of AC power line (60 Hz) directly. The power supply doesn´t need elements such as a rectified bridge, energy-storage capacitors, and a current-limiting resistor in the discharge circuit. In order to control the laser output power, the pulse repetition rate is adjusted up to 60 Hz and the firing angle of SCR gate is varied from 30° to 150°. A ZCS (zero cross switch) circuit and a PIC one-chip microprocessor are used to control the gate signal of SCR precisely. The maximum laser output is 35 W at the total pressure of 18 Torr, the pulse repetition rate of 60 Hz, and SCR gate firing angle of 90°. In addition, the obtained laser pulse width is approximately 3 ms (FWHM). It is a relatively long pulse width, compared with any other repetitively pulsed CO2 laser
Keywords :
gas lasers; laser accessories; laser tuning; pulsed power supplies; switching circuits; thyristor applications; 18 torr; 3 ms; 35 W; 60 Hz; AC power line voltage switching; CO2; PIC one-chip microprocessor; SC gate firing angle; gate signal control; laser discharge circuit; laser output power control; laser pulse width; laser tune circuit; leakage transformer; long pulse duration; low pressure; maximum laser output; power supply; pulse repetition rate; pulsed CO2 laser; zero cross switch circuit; Bridge circuits; Optical pulses; Power lasers; Power supplies; Pulsed power supplies; Space vector pulse width modulation; Switched capacitor circuits; Switches; Thyristors; Voltage;
Conference_Titel :
Industrial Electronics, 2001. Proceedings. ISIE 2001. IEEE International Symposium on
Conference_Location :
Pusan
Print_ISBN :
0-7803-7090-2
DOI :
10.1109/ISIE.2001.931601
