Multi-Color Laser Emission for the Generation of Ultrashort Optical Pulse

The pulse width of an electromagnetic wave is determined by the frequency band width of the wave used. Therefore one femtosecond is the ultimate in pulse width for an optical wave. For this reason several methods have been proposed for the generation of an ultrashort optical pulse. For example resonance/non-resonance four-wave mixing would be one of the candidates for generating multi-color laser emission in an extremely wide spectral region thus breaking the 1-fs barrier. To date numerous emission lines have been generated from the deep-ultraviolet to the near-infrared region ( Ultrashort optical pulses can be utilized in a variety of applications in science and technology. For example an ultrashort optical pulse can be used in the studies of ultrafast phenomena. More practically a laser pulse shorter than 100 fs is reported to be useful in mass spectrometry for observing a molecular ion of triacetone triperoxide an explosive used in terrorist attacks. A train of ultrashort optical pulses in the terahertz region which has been generated in the optical cavity to enhance the nonlinear optical effect would be employed as a clock pulse in optical computation/communication in future advanced industries. Therefore it is important to investigate a new frontier in the generation of multi-color laser emission for Fourier synthesis to generate ultrashort optical pulses and to clarify new trends in the state-of-the-art.