Laser technology, definition, applications, and challenges
Modern Physics, Spring 2015
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A red laser contains a long crystal made of ruby with a flash tube surrounding it. The flash tube is similar to a fluorescent strip light, only it's coiled around the ruby crystal and it flashes every so often like a camera's flash.
How do the flash tube and the crystal make laser light?
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Solid state lasers emits infrared light at 1.064 micrometers.And they have lasing material distributed in a solid matrix.
Figure 2. Solid state laser
Gas lasers (helium and helium-neon, HeNe, are the most common gas lasers) have a output of a visible red light.
Figure 3. Gas lasers
Excimer lasers use reactive gases such as chlorine and fluorine mixed with inert gases such as argon, krypton, or xenon. They produce light in the ultraviolet range.
Dye lasers use complex organic dyes like rhodamine 6G in liquid solution or suspension as lasing media. They are tunable over a broad range of wavelengths.
Figure 4. Dye lasers
Semiconductor lasers (diode lasers) are not solid-state lasers. These electronic devices are generally very small and use low power. [2]
Figure 5. Semiconductor lasers
Applications of laser
Here are the list of the applications of laser: [3]
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Analog sound data is digitized by sampling at 44.1 kHz and coding as binary numbers in the pits on the compact disc. As the focused laser beam sweeps over the pits, it reproduces the binary numbers in the detection circuitry.
Figure 6. How optical drives write CDs/DVDs
Spectroscopy
Laser spectroscopy has led to advances in the precision with which spectral line frequencies can be measured, and this has fundamental significance for our understanding of basic atomic processes.
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