Repetition Rate TEA CO2 Laser Research Articles

Precise measurement for beam pointing stability of high power repetition rate TEA CO2 laser

High power repetition rate TEA CO2 laser emits high power and high pulse energy far-infrared laser, the laser spot and beam pointing stability is difficult to measure with commercial detectors directly. In this paper, a method is proposed to measure the beam pointing stability of high power repetition rate TEA CO2 laser. A laser with average power of 10kW and repetition rate of 400Hz is adopted as sample for measurement. An experimental device is optimally design to attenuate laser power and measure the laser spot. Beam pointing stability can be calculated from the measured result and the aberration caused by the experimental measurement is discussed. A correction algorithm based on the laser parameters is proposed and the beam pointing stability of this TEA CO2 laser can be calculated as 39.93μrad and 145.53μrad in x direction and y direction respectively.

Rapid and conservative ablation and modification of enamel, dentin, and alveolar bone using a high repetition rate transverse excited atmospheric pressure CO[sub 2] laser operating at λ=9.3 μm

Transverse excited atmospheric pressure (TEA) CO(2) lasers tuned to the strong mineral absorption of hydroxyapatite near lambda=9 microm are well suited for the efficient ablation of dental hard tissues if the laser pulse is stretched to greater than 5 to 10 micros to avoid plasma shielding phenomena. Such CO(2) lasers are capable of operating at high repetition rates for the rapid removal of dental hard tissues. The purpose of this study was to test the hypothesis that stretched lambda=9.3-microA CO(2) laser pulses can produce lateral incisions in enamel, dentin, and alveolar bone for dental restorations and implants at repetition rates as high as 400 Hz without peripheral thermal damage. The single pulse ablation rates through enamel, dentin, and bone were determined for incident fluence ranging from (1 to 160 J/m(2)) for laser pulses from 5 to 18 mus in duration. Lateral incisions were produced in hard tissue samples using a computer-controlled scanning stage and water spray, and the crater morphology and chemical composition were measured using optical microscopy and high-resolution synchrotron radiation infrared spectromicroscopy. The residual energy remaining in tooth samples was measured to be 30 to 40% for enamel and 20 to 30% for dentin without water cooling, under optimum irradiation intensities, significantly lower than for longer CO(2) laser pulses. The transmission through 2-m length 300-, 500-, 750-, and 1000-microm silica hollow waveguides was measured and 80% transmission was achieved with 40 mJ per pulse. These results suggest that high repetition rate TEA CO(2) laser systems operating at lambda=9.3 microm with pulse durations of 10 to 20 micros are well suited for dental applications.

Design and performance of a high repetition rate TEA CO2 laser

Design and performance of a high repetition rate TEA CO2 laser

Design and performance of a high repetition rate TEA CO2laser

The design and operational characteristics of a high repetition rate TEA CO2 laser are described. The laser operates at variable pulse repetition frequencies up to 100 Hz. Stable operation is obtained in a closed cycle which includes a gas mixture regenerator. Energies of up to 10 J/pulse are obtained in pulses having 25 MW peak powers. Average powers as high as 500 W are reached at the maximum pulse repetition frequency. The performance of optical components at various pulse repetition frequencies is presented.

Multiwatt optically pumped ammonia laser operation in the 12–13 μm

Design and operating caracteristics of high pulse repetition rate NH3 laser producing up to 20 W of average output power are described. The NH3 laser, operating in the 12–13 μm region was optically pumped with a high pulse repetition rate TEA CO2 laser. Dependences of the NH3 laser output on the pump energy, ammonia and buffer gas pressures and pulse repetition rate have been studied. The conversion efficiency of up to 16% has been received.