The meaning of FREE-ELECTRON LASER is a laser that can be tuned over a wide range of frequencies and that produces electromagnetic radiation by the motion of electrons moving at relativistic velocities in a magnetic field.
The meaning of LASER is a device that utilizes the natural oscillations of atoms or molecules between energy levels for generating a beam of coherent electromagnetic radiation usually in the ultraviolet, visible, or infrared regions of the spectrum; also
The electromagnetic waves cover an extremely broad spectrum of wavelengths, as shown in figure I-1-2. We can detect only a very small segment of this spectrum directly through our sense of sight from approximately 750 to 430 nm. Figure I-1-2: The electromagnetic spectrum. I-2 Refraction ...
Terahertz (THz) frequencies remain among the least utilized in the electromagnetic spectrum, largely due to the lack of powerful and compact sources. The invention of THz quantum cascade lasers (QCLs) was a major breakthrough to bridge the so-called ‘THz gap’ between semiconductor electronic an...
in the intersection region. A laser-induced grating (LIG) can be formed by two different mechanisms: (1)thermalizationof the absorbed laser radiation by absorbing species in the medium via collisions, which results in modulation of the gas density and thus modulation of refractive index, and (...
To enhance the emission spectrum intensity of laser-induced plasma, a method of combining cavity-enhanced laser-induced breakdown spectroscopy (LIBS) with nanoparticles-enhanced LIBS (NELIBS) was proposed. In this paper, the brass with Au-nanoparticles deposited on the surface is placed under the ...
A new theory has been formulated whereby the electromagnetic field inside resonator filled with an active medium is described through an expansion of the field into an angular spectrum of plane waves. The resonator is composed of two identical, circular reflectors of arbitrary size, focal length, ...
in the visible and infrared portions of the spectrum. Different commercial models cover at least the range from the blue portion of the visible spectrum to the mid infrared, near 4 μm. The short-wavelength end of the range can be extended by frequency doubling. For a single device, the ...
[Math Processing Error]2P3/2 [Math Processing Error]5s2np and [Math Processing Error]2F5/2 [Math Processing Error]5s2nf series, showing (a) the spectrum of resonances measured in the 770-720 nm range, with an inset in black indicating energies for the members of the Rydberg series ...
The terahertz (THz) frequency range is the last lacuna in the electromagnetic spectrum, where we have no efficient sources of radiation. Being usually understood as the region of frequencies from 0.1 to 10 THz or, equivalently, of wavelengths from 3 mm to 30 μm, the THz part of th...