Smart Optics or Intelligent Optics is a product that combines traditional optics with modern computer systems. Intelligent optics integrates modern technologies such as new materials, computer information, electronics, and compact processing, greatly expanding the application fields of traditional optical systems.
Intelligent optics is based on adaptive optics and active optics technology, and has close connections with disciplines such as microelectronics, information optics, and optoelectronics - intelligent optics and related disciplines promote and develop together.
The concept of intelligent optics
Foreign scientist Greenaway defines intelligent optics as optical technology and components that can achieve dynamic adjustment. Intelligent optics is a constantly evolving concept, originally built on adaptive optics and active optics as a technology - using reflective optical components as the main equipment for dynamic modulation of wavefront phase. Here, a brief introduction will be given to adaptive optics and active optics.
1.1 Adaptive Optics
Before introducing adaptive optics technology, let's briefly introduce the concept of "atmospheric turbulence". Atmospheric turbulence is essentially a form of motion in the atmosphere. Due to the presence of atmospheric turbulence, the horizontal and vertical exchange of water vapor, heat, momentum, and pollutants in the atmosphere is greatly enhanced, and the increasing intensity of this motion is much greater than that of molecular motion.
We know that the atmosphere is one of the transmission media for light waves. When light waves propagate in the atmosphere, they are affected by atmospheric turbulence, resulting in wavefront distortion (the wavefront changes after passing through the transmission medium). The application of adaptive optics technology aims to compensate for wavefront distortion caused by atmospheric turbulence or other factors. At present, adaptive optics mainly plays an important role in intelligent optics to realize high-speed and small amplitude wavefront modulation using deformable mirrors.
1.2 Active Optics
Active optics is a wavefront correction technique aimed at correcting the deformation of telescope optical systems and their supports caused by factors such as temperature and gravity. In addition to the influence of atmospheric turbulence, factors such as temperature, pressure, gravity, etc. may interfere with the normal observation of telescopes (wavefront deformation). Through active optical technology, computer actuators can be controlled to adjust their working state according to the wavefront deformation situation, in order to monitor and eliminate wavefront deformation in real time. In short, active optics is a technology that uses a built-in "corrector" in a telescope to actively change the shape of the mirror surface to improve image quality.
With the further development of intelligent optics, the concept of intelligent optics based on adaptive optics and active optics has been further supplemented, which refers to optical technologies, components, and systems with dynamic adjustment, automatic control, and measurement capabilities.
At present, refractive diffractive optical components and optoelectronic components are also widely used in the process of measuring, controlling, and modulating wavefront phase; The application of dynamically adjusting optical components in intelligent optics further expands the functionality of optical systems, achieving modulation and measurement of parameters such as wavefront amplitude, polarization, wave frequency, and light intensity.
Intelligent optics has further promoted the development of traditional optics. For some optical systems with complex designs and difficult to achieve through conventional processing, the use of intelligent optics can effectively simplify the design of the optical system and improve its performance. Intelligent optics has a wide range of applications in fields such as astronomy and medicine.
2. Dynamic optical modulation
As mentioned earlier, wavefront distortion is an important factor affecting optical imaging. Adaptive optics technology and active optics technology in intelligent optical systems are both aimed at correcting or compensating for wavefront distortion. As one of the core technologies of intelligent optics, dynamic optical modulation is also used to correct or compensate for wavefront distortion, thereby improving the performance of optical systems. Here, focusing on the modulation (correction or compensation) of wavefront distortion, several commonly used dynamic optical modulation techniques are introduced.
2.1 Wavefront dynamic modulation technology
The wavefront modulator is the core optical component to realize the dynamic modulation technology of wavefront, which is used to modulate the wavefront phase or amplitude (some wavefront modulators have the function of both wavefront phase and wavefront amplitude modulation). The wavefront modulator is usually composed of a reflector and an actuator (the two are combined into an array). According to the different structures of the spliced mirror surface and the whole mirror surface of the reflector, the wavefront modulator can be divided into discrete and continuous forms. The commonly used actuators for adaptive optics and active optics include electromechanical actuators, pressure actuators, piezoelectric actuators, and microcomputer actuators.
Active optics technology is mostly applied to large aperture reflective telescopes, which can achieve low speed and large amplitude wavefront modulation, so it needs strong support. Mechanical and electrical actuators and pressure actuators are the main units that constitute the active optical dynamic support structure, providing sufficient support force for the active optical dynamic support structure.
2.2 Other dynamic modulation techniques
Light intensity dynamic modulation technology: Light intensity dynamic modulation technology mainly relies on spatial light modulators and is applied in the field of projection display optics. The modulator used for dynamic modulation of light intensity is generally a discrete structure.
Spectral dynamic modulation: Spectral dynamic modulation mainly uses acousto-optic tuning filters and liquid crystal tuning filters to dynamically filter the spectrum. This technology has a wide range of applications in many optical systems, such as microscopy imaging, remote sensing imaging, and other fields. The response speed of acousto-optic tuning filters is relatively high, but their image quality is relatively insufficient; The image quality of liquid crystal tuning filters is high, but their corresponding speed is low.
3. Dynamic optical detection
Dynamically control optical modulation based on wavefront phase and intensity information. The basis for achieving dynamic control of light intensity and wavefront is various photoelectric sensors. For example, photomultiplier tubes, avalanche diodes, optocoupler devices, etc. Photoelectric sensors can directly detect light intensity information; Photoelectric sensors and other optical devices can form wavefront detectors to detect wavefront information. According to the different detection positions of wavefront detectors, they can be divided into two categories: pupil wavefront detectors and focal wavefront detectors; According to the different wavefront reconstruction processes, it can be divided into two categories: linear wavefront detectors and nonlinear wavefront detectors.
4 Intelligent Optical Systems
In summary, we can define an intelligent optical system as an optical system that has dynamic optical modulation or (and) dynamic optical detection capabilities and can be dynamically controlled based on optical characteristics. Currently, the dynamic control function of intelligent optical systems can be divided into two categories: open-loop control and closed-loop control. The open-loop control system mainly includes a modulator and a controller; The closed-loop control system mainly includes three parts: modulator, detector, and controller. Intelligent control systems can be divided into two categories: adaptive control systems and active control systems.
Active optical systems are mainly used in reflective and large aperture telescopes to modulate the wavefront distortion of the telescope's main mirror. Currently, active optics has become an essential technology for large aperture telescopes.
With the continuous increase of telescope aperture, some space-based telescopes have also begun to adopt active optical technology to improve image quality. For example, the famous James Webb Space Telescope achieved ideal image quality by using a complex stitched mirror active optical system.
References
1. Wang Jianli, Liu Xinyue. Concept and Development of Intelligent Optics. China Optics, 2013, 6 (4): 437-448
 
3. Xu Kai. The important role of automatic optical detection equipment in intelligent development. China High end SMT Academic Conference, 2015
4. Liu Chuang. An analysis of the reasons for the transformation from traditional optical instruments to modern optical instruments Technology Wealth Guide, 2014 (14): 232