• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.40.3-40
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• 2001

The pulsed Nd:YAG laser is the most commonly used type of solid-state laser in many fields. In material processing and medical treatment, the power density control of a laser beam Considered to be significant, which depends on the flashlamp current pulse width and pulse repetition rate. For general laser power supply to control the laser power density, the secondary of the power transformer is connected to the rectifier and filter capacitor. The output of a rectifier is applied to a switching element in the secondary of the transformer. So power supply is complicated and the loss of switching is considerably. In addition, according to increasing pulse repetition rate, charged energy of energy-storage capacitor bank is not transferred sufficiently to flashlamp, and laser output efficiency decreases. In this study, we have ...

• Korean Journal of Optics and Photonics
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• v.3 no.1
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• pp.37-42
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• 1992

Nd:YLF regenerative amplifiers have proved to be reliable source for producing stable short pulses of high repetition rate. We used a convex-concave mirror design to optimize output energy and stability while minimizing the energy density on critical intracavity optical components. The Kd:YLF laser pulse is used as a seed pulse which has pulse width of 40 ps, energy of 100pJ, and wavelength of 1053 nm. The amplifier yields stable 1 mJ pulses at 3.5 kHz repetition rate, and the maximum energy is measured as 5 mJ.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.6
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• pp.304-308
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• 2002

We demonstrate a simple pulsed $CO_2$ laser with millisecond long pulse duration in a tube at a low pressure of less than 30 Torr. The novel power supply for our laser system switches the voltage of the AC power line (60Hz) directly. The power supply doesn't need elements such as a rectifier bridge, energy-storage capacitors, or a current-limiting resistor in the discharge circuit. To control the laser output power, the pulse repetition rate is adjusted up to 60Hz and the firing angle of SCR(Silicon Controlled Rectifier) gate is varied from 30。 to 150。. A ZCS (Zero Crossing Switch) circuit and a PIC one-chip microprocessor are used to control precisely the gate signal of the SCR. The maximum laser output of 35 W is obtained at a total pressure of 18 Torr, a pulse repetition rate of 60 Hz, and a SCR gate firing angle of 90。 . In addition, the resulting laser pulse width is approximately 3㎳(FWHM). This is a relatively long pulse width, compared with other repetitively pulsed $CO_2$ lasers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.57-60
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• 2000

In this paper, it is purpose to develop a pulsed $CO_2$ laser with stable output at pulse repetition rate range of 2 KHz. We used a IGBT as a switching device. The laser cavity was fabricated as an axial and water cooled type. It was used a ring blower to increase a cooling effect The laser performance characteristics as parameters, such as pulse repetition rate, gas pressure have been investigated. The experiment was done under 3 electrode-type instead of 2 electrode-type. To achieve 3 electrode-type, we used two pulse-transformers which is operated parallel. As a result, the maximum output was about 28 W at the total pressure of 20 Torr, the gas mixture $Co_2$:$N_2$:He=1:9:15 and the pulse repetition rate of 1300 Hz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.6
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• pp.1141-1149
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• 2009

Pulse style Nd: YAG Laser is suitable in skin remaking treatment, in compliance with the ramp continuous oscillation until of course normal takeoff, the Q-switch and mode motive takeoff the takeoff form which is various is possible and it is coming to be widely used in microsurgery and skin remaking promotion. According to therapeutic objective very it is important to control a energy density. Control of energy density the method which controls the pulse repetition rate of Laser output is mainly used. From the research which it sees pulse style Nd: It will be able to control the pulse repetition rate of YAG, the 2nd harmonic occurrence Laser (second harmonic generation: SHG) with the energy part of the light-wave which is a footnote wave number will hold and nonlinear decision it propagates and is converted by energy of the light-wave which is a footnote wave number the actual condition which and it applies the second harmonic occurrence in compliance with a secondary nonlinearity it leads and until skin deep part therapeutic possibility is the thing it will be able to observe simply.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.507-510
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• 2005

High voltage pulse power supply using Marx generator and solid-state switches is proposed in this study. The Marx generator is composed of 12 stages and each stage is made of IGBT stack, two diode stacks, and capacitor. To charge the capacitors of each stage in parallel, inductive charging method is used and this method results in high efficiency and high repetition rates. It can generate the pulse voltage with the following parameters: Voltage: up to 120kv Rising time: sub ${\mu}S$ Pulse width: up to $10{\mu}S$, Pulse repetition rate: 1000pps The proposed pulsed power generator uses IGBT stack with a simple driver and has modular design. So this system structure gives compactness and easiness to implement total system. Some experimental results are included to verify the system performances in this paper.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2098-2100
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• 2000

We propose pulsed $CO_2$ laser below 30W by the AC(60Hz) switching control of leakage transformer primary which has some advantage of cost and size compared to a typical pulsed power supply. Pulse repetition rate is adjusted from 5Hz to 60Hz to control laser output. In this laser, a low voltage open loop control for high voltage discharge circuit is employed to avoid the HV sampling or switching and high voltage leakage transformer is used to convert rectified low voltage pulse to high voltage one. A ZCS(Zero Cross Switch) circuit and a PIC one-chip microprocessor are used to control gate signal of SCR precisely. The pulse repetition rate is limited by 60Hz due to the frequency of AC line and a high leakage inductance. The maximum laser output was obtained about 23W at pulse repetition rate of 60Hz, total gas mixture of $CO_{2}/N_{2}$/He = 1/9/15, SCR gate trigger angle 90$^{\circ}$, and total pressure of 18Torr.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2101-2103
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• 2000

In this paper, it is purpose to develop a pulsed $CO_2$ laser with stable output at pulse repetition rate range of 2 kHz. We used a IGBT as a switching device. The laser cavity was fabricated as an axial and water cooled type. It was used a ring blower to increase a cooling effect. The laser performance characteristics as parameters, such as pulse repetition rate, gas pressure have been investigated. The experiment was done under 3 electrode-type instead of 2 electrode-type. To achieve 3 electrode-type, we used two pulse-transformers which is operated parallel. As a result. the maximum output was about 28 W at the total pressure, of 20 Torr(the gas mixture $CO_2$:$N_2$:He=1:9:15 and the pulse repetition rate of 1300 Hz).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2685-2692
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• 2009

We propose pulsed magnetic stimulation below 30W by the AC(60Hz) switching control of leakage transformer primary which has some advantage of cost and size compared to a typical pulsed power supply. Pulse repetition rate is adjusted from 5Hz to 60Hz to control magnetic stimulation output. In this magnetic stimulation, a low voltage open loop control for high voltage discharge circuit is employed to avoid the HV sampling or switching and high voltage leakage transformer is used to convert rectified low voltage pulse to high voltage one. A ZCS(Zero Cross Switch)circuit and a DSP & FPGA are used to control gate signal of SCR precisely. The pulse repetition rate is limited by 60Hz due to the frequency of AC line and a high leakage inductance. The maximum magnetic stimulation output was obtained about 33W at pulse repetition rate of 60Hz, total 40, 80, 120, $160^{\circ}$, SCR gate trigger angle $90^{\circ}$ and total output.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.44-44
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• 2003

Free electron lasers (FEL) have, at least, the following advantages in comparison to conventional lasers： FEL can be designed for any arbitrary given emission wavelength. It is continuously tunable within wide band. Easy to get single-mode emission. Easily controlled emission structure (pulse duration, repetition rate, and pulse energy). (omitted)