Optics and laser branch of physics' world is based on exact recognition of different aspects of light and the corresponding properties of light expected in each of those classifications. Distinct outlooks for investigating of light come up from the comparison of medium physical parameters with the fundamental characteristics of light like its wavelength(frequency), intensity(power) and phase. According to this assimilate study various disciplines of optical science such as geometrical optics, wave optics, nonlinear optics, quantum optics and Fourrier optics are emerged. Of course, understanding of light sources and the mechanisms under which the generation and detection of light are take placed is also the duty of this branch of physics. Accordingly, a laser is considered as a monochrome, coherent and directional light source.

On the other hand, optics and lasers branch of physics is an introduction to engineering and applied optics, including rays, waves, lasers, holography, fibers and optical waveguides and laser communication. Therefore, this field of physics accentuate on physical principles, applications and instrumentation.

Furthermore, the accurate interactions of different aspects of light, rays, waves and particles or photons, with different media such as metals, dielectrics, semiconductors and magnetic materials are also make the main activities in this field.

 Every day, some significant phenomena and features of light are revealed from these researches so that in turn provide the starting point for new technologies and stablished advance methods for more careful measurements used in experimental evidence of theoretical envisions in other branches of physics. The best evidence for this claim is the detection of gravitational waves ( general relativity ) by professional optical instrument means Mykelson interferometer based on squeeze light. Certainly, these concept and technique are pronounced only in quantum nonlinear optics.

Also, nowadays any one hear from the appearance of quantum technology, it is clear that the quantum properties of light and existence of novel instruments based on quantum optics prepare a secure foundation for this new technology.