Advances in Adaptive Optics for Astronomy
Introduction
Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of incoming wavefront distortions by deforming a mirror in order to compensate for the distortion. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, in microscopy, optical fabrication and in retinal imaging systems to reduce optical aberrations. Adaptive optics works by measuring the distortions in a wavefront and compensating for them with a device that corrects those errors such as a deformable mirror or a liquid crystal array.
History and Development
The development of adaptive optics dates back to the early 1950s, when the concept was first proposed by astronomer Horace Babcock. However, it was not until the 1970s that the technology was first implemented in a practical application, with the development of the first adaptive optics systems for astronomical telescopes. Since then, the technology has advanced significantly, with the development of more sophisticated wavefront sensors, deformable mirrors, and control algorithms. The 1990s saw the first use of adaptive optics in large, ground-based telescopes, which significantly improved the resolution of these instruments.
Principles of Adaptive Optics
The basic principle of adaptive optics is to correct for the distortions in a wavefront that are caused by atmospheric turbulence or other factors. This is achieved by using a wavefront sensor to measure the distortions, and a deformable mirror to correct for them. The wavefront sensor measures the distortions by comparing the incoming wavefront with a reference wavefront, and the deformable mirror is controlled by a computer that uses the measurements from the wavefront sensor to calculate the necessary corrections.
Components of an Adaptive Optics System
An adaptive optics system typically consists of three main components: a wavefront sensor, a deformable mirror, and a control system. The wavefront sensor measures the distortions in the incoming wavefront, the deformable mirror corrects for these distortions, and the control system calculates the necessary corrections and controls the deformable mirror.
Applications in Astronomy
Adaptive optics has been widely used in astronomy to improve the resolution of ground-based telescopes. By correcting for the distortions caused by atmospheric turbulence, adaptive optics allows these telescopes to achieve a resolution that is comparable to that of space-based telescopes. This has allowed astronomers to make more detailed observations of celestial objects, leading to numerous scientific discoveries.
Future Developments
The future of adaptive optics in astronomy looks promising, with several new developments on the horizon. These include the development of multi-conjugate adaptive optics systems, which can correct for distortions over a larger field of view, and the use of laser guide stars, which can provide a reference source for the wavefront sensor when there are no bright stars in the field of view.
See Also
