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  2. Distributed Bragg reflector - Wikipedia

    en.wikipedia.org/wiki/Distributed_Bragg_reflector

    Time-resolved simulation of a pulse reflecting from a Bragg mirror. A distributed Bragg reflector (DBR) is a reflector used in waveguides, such as optical fibers.It is a structure formed from multiple layers of alternating materials with different refractive index, or by periodic variation of some characteristic (such as height) of a dielectric waveguide, resulting in periodic variation in the ...

  3. Waveplate - Wikipedia

    en.wikipedia.org/wiki/Waveplate

    Two waves differing by a quarter-phase shift for one axis Creating circular polarization using a quarter-wave plate and a polarizing filter. For a quarter-wave plate, the relationship between L, Δn, and λ 0 is chosen so that the phase shift between polarization components is Γ = π/2. Now suppose a linearly polarized wave is incident on the ...

  4. Quarter-wave impedance transformer - Wikipedia

    en.wikipedia.org/wiki/Quarter-wave_impedance...

    The quarter wave transformer is an alternative to a stub; but, whereas a stub is terminated in a short (or open) circuit and the length is chosen so as to produce the required impedance transformation, the λ/4 transformer is in series with the load and its length and characteristic impedance are designed to produce the required impedance ...

  5. Collinear antenna array - Wikipedia

    en.wikipedia.org/wiki/Collinear_antenna_array

    Collinear dipole array on repeater for radio station JOHG-FM on Mt. Shibisan, Kagoshima, Japan. In telecommunications, a collinear antenna array (sometimes spelled colinear antenna array) is an array of dipole or quarter-wave antennas mounted in such a manner that the corresponding elements of each antenna are parallel and collinear; that is, they are located along a common axis.

  6. Optical coating - Wikipedia

    en.wikipedia.org/wiki/Optical_coating

    This periodic system significantly enhances the reflectivity of the surface in the certain wavelength range called band-stop, whose width is determined by the ratio of the two used indices only (for quarter-wave systems), while the maximum reflectivity increases up to almost 100% with a number of layers in the stack.

  7. Stub (electronics) - Wikipedia

    en.wikipedia.org/wiki/Stub_(electronics)

    About 1/8 wavelength long: (left) 200 MHz stub is 19 cm, (right) 300 MHz stub is 12.5 cm 10 kW FM broadcast transmitter from 1947 showing quarter-wave resonant stub plate tank circuit. In microwave and radio-frequency engineering, a stub or resonant stub is a length of transmission line or waveguide that is connected at one end only. The free ...

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  9. Pockels effect - Wikipedia

    en.wikipedia.org/wiki/Pockels_effect

    The quarter wave or half wave voltage requirements increase with crystal aperture size, but the requirements can be reduced by lengthening the crystal. Two or more crystal can be incorporated into a transverse Pockels cell. One reason is to reduce the voltage requirement by extending the overall length of the Pockels cell.