Definition of active optics

Photonics Dictionary

active optics: Active optics refers to a technology used in telescopes and other optical instruments to improve the quality of images by dynamically adjusting the shape of optical components, such as mirrors, in real-time. This technology compensates for various distortions and aberrations that can degrade the quality of the image, ensuring that the instrument maintains optimal performance under changing conditions.

Real-time adjustment: Active optics involves the use of sensors, actuators, and control systems to continuously monitor and correct the shape of optical elements. This allows for real-time adjustments to compensate for deformations caused by gravity, temperature changes, wind, and other environmental factors.

Applications in telescopes: Large astronomical telescopes, such as the Very Large Telescope (VLT) and the European Extremely Large Telescope (E-ELT), utilize active optics to maintain the precise shape of their primary mirrors. This ensures that the telescope produces sharp and clear images despite structural and environmental influences.

Difference from adaptive optics: Active optics is different from adaptive optics. While active optics corrects for slow and predictable distortions in the optical components, adaptive optics corrects for rapid and unpredictable distortions caused by atmospheric turbulence. Both systems can be used together to achieve high-quality imaging.

Components: The system typically includes wavefront sensors to detect distortions, actuators to adjust the shape of mirrors, and a control system to process the sensor data and command the actuators.

Overall, active optics plays a critical role in modern optical instruments, particularly in astronomy, where it significantly enhances the capability to observe distant celestial objects with high precision.