Alternatively, polarization can be represented as a point on the surface of the Poincaré sphere, with as the longitude and , where , as the latitude.
When applied to the Poincaré sphere (also known as the Bloch sphere), the basis kets (
In condensed matter physics, the Poincaré sphere is also known as the Bloch sphere.
Polarization controllers with tracking speeds of up to 100 krad/s on the Poincaré sphere are commercially available (see external link at the bottom).
Polarization scramblers usually vary the normalized Stokes vector of the polarization state over the entire Poincaré sphere.
Over a long-distance system, these drifts accumulate progressively without limit, resulting in rapid and erratic rotation of the polarized light's Jones vector over the entire Poincaré sphere.
Henri Poincaré | Raymond Poincaré | Sphere | sphere | Poincaré sphere | Poincaré | Riemann sphere | Bloch sphere | The Sphere (newspaper) | The Sphere | Star Ocean: Blue Sphere | Sphere packing | sphere packing | Sphere Origins' | Poincaré disk model | Poincare | McClintic Sphere | Inner sphere electron transfer | Hand with Reflecting Sphere | Greater East Asia Co-Prosperity Sphere | Franc Poincaré | François Morellet, ''Sphere - Matter'' 1962, Skupturengarten Abteiberg Museum in Mönchengladbach | Ewald's sphere | Advanced Inertial Reference Sphere |
In 2003, lack of structure on the largest scales (above 60 degrees) in the cosmic microwave background as observed for one year by the WMAP spacecraft led to the suggestion, by Jean-Pierre Luminet of the Observatoire de Paris and colleagues, that the shape of the Universe is a Poincaré sphere.