Electromagnetic spectrum, visible light

Different types of electromagnetic radiation make up the electromagnetic spectrum. Visible light - the radiation that our eyes can detect - makes up only a small part of the electromagnetic spectrum. 

Figure 32.19. The Electromagnetic Spectrum. Visible light has wavelengths between 300 and 850 nanometers.

FIGURE 9.4 Electromagnetic spectrum (visible light and telecommunications fiber operation). (Courtesy of Corning Cable Systems LLC and Corning Inc.)... 

The Electromagnetic Spectrum Visible light represents a small region of the electromagnetic spectrum (Figure 7.3). All waves in the spectrum travel at the same speed through a vacuum but differ in frequency and, therefore, wavelength. 

Figure 24.1 The electromagnetic spectrum. Visible light (400-700 nm) constitutes only a small portion of the spectrum that ranges from gamma rays (<1 pm long) to radiowaves that are thousands of meters long.

C07-0007. A compact disc player uses light of frequency 3.85 X lO s to read the information on the disc, (a) What is this light s wavelength (b) In what portion of the electromagnetic spectrum (visible, ultraviolet, and so on) does this wavelength fall (c) What is the energy of one mole of photons at this frequency ... 

What we commonly refer to as light is actually the visible portion of the electromagnetic spectrum. All light has certain common characteristics including wavelength, frequency, and amplitude. 

In the electromagnetic spectrum, the ultra violet region is between that of X-rays and visible light. This corresponds to the energies hv ot one hundred to a few tens of electron-volts (wavelengths from 180 to 400 nm). 

The so-called peak power delivered by a pulsed laser is often far greater than that for a continuous one. Whereas many substances absorb radiation in the ultraviolet and infrared regions of the electromagnetic spectrum, relatively few substances are colored. Therefore, a laser that emits only visible light will not be as generally useful as one that emits in the ultraviolet or infrared ends of the spectrum. Further, witli a visible-band laser, colored substances absorb more or less energy depending on the color. Thus two identical polymer samples, one dyed red and one blue, would desorb and ionize with very different efficiencies. 

The scattering of visible light by polymer solutions is our primary interest in this chapter. However, since is a function of the ratio R/X, as we saw in the last section, the phenomena we discuss are applicable to the entire range of the electromagnetic spectrum. Accordingly, a general review of the properties of this radiation and its interactions with matter is worthwhile before a specific consideration of scattering. 

In 1957, this team of brothers-in-law started working together on Townes s idea for an optical maser. They found atoms that they felt had the most potential, based on transitional probabilities and lifetimes. However, there was still one major problem In the visible light portion of the electromagnetic spectrum, atoms don t remain in an excited state as long as... 

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