Chromatic dispersion effect of optical components
2023-11-9
Chromatic dispersion can also be defined as the dispersion in the optical element rather than in the medium. At this time, it is necessary to perform Taylor expansion on the total phase delay of the component (rather than on the wave number, that is, the phase delay per unit length), and then obtain the total group delay dispersion (units are seconds squared), instead of unit length as mentioned above. dispersion.
The chromatic dispersion of an optical element may only come from the dispersion of its component parts, and sometimes a large part of the dispersion comes from the interference effect. For example, the Gires-Tournois interferometer causes dispersion in the optical resonator due to interference effects. The same situation exists in other types of interferometers. When the propagation lengths are very different, the dispersion produced by the interference effect is very large.
Geometric effects can also produce chromatic dispersion. For example, prism pairs are often used to compensate for dispersion in mode-locked lasers. Among them, since the refraction of the prism surface depends on the wavelength, the path length depends on the wavelength, resulting in chromatic dispersion. The laser resonator contains Brewster angle optical elements, so similar effects exist. In addition, Bragg gratings can be used for dispersive pulse compression.
The chromatic dispersion of an optical element may only come from the dispersion of its component parts, and sometimes a large part of the dispersion comes from the interference effect. For example, the Gires-Tournois interferometer causes dispersion in the optical resonator due to interference effects. The same situation exists in other types of interferometers. When the propagation lengths are very different, the dispersion produced by the interference effect is very large.
Geometric effects can also produce chromatic dispersion. For example, prism pairs are often used to compensate for dispersion in mode-locked lasers. Among them, since the refraction of the prism surface depends on the wavelength, the path length depends on the wavelength, resulting in chromatic dispersion. The laser resonator contains Brewster angle optical elements, so similar effects exist. In addition, Bragg gratings can be used for dispersive pulse compression.
