CO2 laser beam

CO2 and Twin CO2. A CO2 laser beam cannot penetrate copper foil nnless the foil is very thin, less than 5 pm, and the surface is treated to be dark to absorb the CO2 laser beam (this process is called CO2 laser direct drilling and will be treated later). 

The decomposition of gaseous PH3 in a focused CO2 laser beam is not an IR multiphoton decomposition, but due to a dielectric breakdown. The decomposition arises from the interaction of the generated free electrons with PH3. The decomposition is accompanied by a visible chemiluminescence stemming from formed PH2, PH, H2, H, and probably HJ [4]. 

In the case of using an articulated arm to propagate a CO2 laser beam that is in the infrared (invisible), a co-propagating visible beam (usually a red beam from a He-Ne laser or a diode laser) is used as an aiming beam (Prasad, 2003). 

Figure 7. Top. (M-H)- ion of sucrose formed by desorption with pulsed CO2 laser beam. Bottom. Dissociation upon irradiation with the cw CO2 laser. Experimental conditions are same as in the top spectrum.

Fig.5.113. Generation of tunable FIR radiation by frequency mixing of two CO2-laser beams with a microwave in a MIM diode

Submicron pSiC powder by reacting silane and acetylene in a 10-50 W continuous-wave CO2 laser beam.P" l 

Figure 6. Radial temperature distribution in the (Mg, Fe)Si03 sample heated with a defocused CO2 laser beam at 29 GPa. Temperatures were measured (symbols) in 4 pm steps with a spatial resolution of 2.5 pm. In the central region of the heated area (with about 30 pm in diameter) the temperature gradients are below 10Kpm. After [21].

Fig. 1 Experimental set up. To prevent external sound from entering, the laser-irradiated area is enclosed in a sound-proof box. The CW CO2 laser beam is focused by a ZnSe lens (focal length 10 cm)

As a general rule it can be assumed that the lensing effect can be neglected if the difference in A is smaller than X/10 [51], or 1 pm for a CO2 laser beam. As shown in 

Helisys Inc., Torrence. CA. USA Laminated Object Manufacturing (LOM) Self-adhesive paper and plastic films cutting of the films layer by layer with a CO2 laser beam 

One potential, and perhaps unexpected, application of conductive polymers is for the definition of conductive tracks on printed circuit boards. Rubner et al. [98] exploited the thermal properties of PPS to enable the selective introduction of conductivity by doping. By using a heat gun or a CO2 laser beam and a suitable masking procedure, the PPS could be made to undergo a premelting crystallization at 150 C, such that there 

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