As we all know, because of light, people can see this colorful world and survive in this world. Therefore, there are many light phenomena and their applications in our lives. Whether it is construction art, sculpture, painting and dance art, many fields are inseparable from the existence of light, and because of the existence of light, it is more dazzling and eye-catching.

So how does the light of the present exert its effect on humanity? And how did light develop into modern optics?

In the middle of the 20th century, with the emergence of new technologies, new theories have also been developed continuously. Due to the extensive application of optics, many new sub-disciplines or marginal disciplines have been gradually formed. Geometric optics is a specialized discipline developed for the design of various optical instruments, with the progress of science and technology, physical optics is also more and more showing its power, such as light interference is still an irreplaceable means of precision measurement, diffraction grating is an important spectrophotometric instrument, Spectroscopy has played a key role in human understanding of the microstructure of matter (such as atomic structure, molecular structure, etc.). People combine mathematics, information theory and light diffraction to develop a new discipline - Fourier optics, which is applied to information processing, image quality evaluation, optical computing and other technologies. In particular, the invention of the laser can be said to be a revolutionary milestone in the history of optical development, because the laser has a series of unique properties such as high intensity, good monochromism, and strong directivity, since its advent, it has been quickly applied to material processing, precision measurement, communication, ranging, holographic detection, medical treatment, agriculture and other extremely wide range of technical fields, and has achieved excellent results. In addition, lasers show promising prospects for isotope separation, storage, information processing, controlled nuclear fusion, and military applications.

Optics, a branch of physics, is an ancient natural discipline that has been developed for thousands of years. Around the 17th century, optics had initially formed an independent discipline. The corpuscular theory represented by Newton and the corresponding geometrical optics; The wave theory represented by Huygens and the corresponding wave optics constitute the two pillars of optical theory. By the end of the nineteenth century, Maxwell's genius summed up and expanded the then known knowledge of electromagnetism, and proposed Maxwell's equations, which pushed wave optics to a higher stage. However, people's further understanding of light is inseparable from the establishment of quantum mechanics and relativity. On the one hand, optics in the nineteenth century and before provided the basis for the establishment of these two epoch-making physical theories. On the other hand, the establishment of these two theories has deepened human's in-depth understanding of optical phenomena. From the 17th century to the present, the development of optics has experienced five historical periods, such as the embryonic period, the geometric optics period, the wave optics period, the quantum optics period and the modern optics period.

The modern optical period mainly started from the middle of the 20th century, which includes laser optics, nonlinear optics, fiber optics, thin film optics and integrated optics, information optics, Fourier transform optics, optoelectronics and other new optical branches. Especially after the advent of laser, optics began to enter a new period, so that it has become an important part of modern physics and modern science and technology frontier. The most important of these achievements was the discovery of the stimulated radiation of atoms and molecules predicted by Einstein in 1916, and the creation of many specific techniques for generating stimulated radiation. When studying radiation, Einstein pointed out that under certain conditions, if the stimulated radiation can continue to stimulate other particles, causing a chain reaction, and obtain the amplification effect like an avalanche, you can finally get a highly monochromatic radiation, that is, laser.

Another important branch of optics consists of imaging optics, holography, and optical information processing. This branch can be traced back to the theory of microscope imaging proposed by Abbe in 1873 and the experimental verification completed by Porter in 1906. In 1935, Zelnick proposed the phase contrast observation method and made the phase contrast microscope by Zeiss factory, for which he won the 1953 Nobel Prize in physics; In 1948, Gaber proposed the wave-front reproduction principle, the precursor of modern holography, for which Gaber was awarded the 1971 Nobel Prize in physics.

Since the 1950s, people began to combine mathematics, electronic technology and communication theory with optics, introduced the concepts of spectrum, spatial filtering, carrier, linear transformation and related operations to optics, updated classical imaging optics, and formed the so-called "Fourier optics". Coupled with the coherent light provided by the laser and the holography improved by Leith and Apatnex, a new field of science was formed - optical information processing, or information optics. Information optics technology is also known as optical information processing, it is the application of information optics theory to specifically solve the reception and transmission of optical information, processing and confirmation and other aspects of knowledge. The characteristics of optical information processing is that it can process two-dimensional images at the same time, and the processing information is particularly large, and the processing speed is extremely fast. The Fourier transform of a photo takes several hours or even longer to complete with a computer, but with an optical lens, it is completed in an instant! Optical fiber communication is an important achievement based on this theory, which provides a new technology for information transmission and processing.

In short, the combination of modern optics and other disciplines and technologies has played an increasingly important role and influence in people's production and life, providing a powerful scientific and technological force for people to understand nature, transform nature and improve labor productivity.