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Wavelength is the length of a single cycle of a wave, as measured by the distance between one peak of a wave and the next. It is often designated as λ.

Wavelength is designated as λ here.

In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.[1]

The concept can also be applied to periodic waves of non-sinusoidal shape.[1][2] The term wavelength is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids.[3]

Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.[4]

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  1. 1.0 1.1 Hecht, Eugene (1987). Optics (2nd ed.). Addison Wesley. pp. 15–16. ISBN 0-201-11609-X. 
  2. Brian Hilton Flowers (2000). "§21.2 Periodic functions". An introduction to numerical methods in C++ (2nd ed.). Cambridge University Press. p. 473. ISBN 0198506937. 
  3. Keqian Zhang and Dejie Li (2007). Electromagnetic Theory for Microwaves and Optoelectronics. Springer,. p. 533. ISBN 9783540742951. 
  4. Theo Koupelis and Karl F. Kuhn (2007). In Quest of the Universe. Jones & Bartlett Publishers. ISBN 0763743879.