Hullámfrontérzékelk

A hullámfrontérzékelő, often translated as wavefront sensor, is an optical instrument used to measure the spatial variations of a wavefront. This measurement is crucial in various fields, including adaptive optics, interferometry, and optical testing. A wavefront describes the shape of a propagating light wave, and distortions or imperfections in the optical system can alter this shape. Hullámfrontérzékelők allow for the characterization and correction of these distortions.

There are several common types of hullámfrontérzékelők. Shack-Hartmann sensors are widely used and consist of an array of microlenses. Each microlens focuses light from a specific portion of the incoming wavefront onto a detector, such as a CCD or CMOS camera. The position of the focused spot on the detector indicates the local slope of the wavefront, and by analyzing the positions of all spots, the overall wavefront shape can be reconstructed.

Another type is the Curvature sensor. This method measures the second derivative of the wavefront, which is related to its curvature. It typically uses a lens and a defocused image. By analyzing the intensity distribution in the defocused image, the wavefront curvature can be determined.

Pyramidal sensors are also employed, which use a pyramid-shaped mirror to split the incoming light into four beams. The relative positions of these beams on a detector reveal information about the wavefront's phase.

The data obtained from a hullámfrontérzékelő can then be used to control corrective elements, such as deformable mirrors, in real-time. This process is fundamental to adaptive optics systems, which aim to improve image quality by compensating for atmospheric turbulence or other optical aberrations.