The branch of optics include the study of the properties of light on interaction with an ‘element’ as well as the construction of such elements to produce a desired behavior of light. The best ever optical element that a scientist has ever ‘seen’ is the eye. What the eyes can see, the visible region, span just a few hundred nanometers of the electromagnetic spectrum. While there can be specializations in visible light optics, infrared optics, microwave optics etc., it is really the length span characteristic of a wave called the wavelength, in comparison to the size of the optical element that determines the suitable domain of study.

Wave optics domain is where the wavelength is comparable to the size of the optical element. It encompasses the study of ray optics which is relevant only when the wavelength is much smaller than the size of the optical element. The domain of quantum optics, that can explain wave optics as well, becomes necessary where the study cannot be done without the ‘photon’ or quantum picture of light. Reflection and refraction can be explained by ray picture; diffraction, interference, polarization and scattering require wave picture.

We primarily use wave optics in designing and analyzing diffractive optical elements (DOE). Singular optical elements (SOE) can generate vortex beams which are made up of photons that carry a certain angular momentum. Most optical experiments in lab – like testing DOEs/ SOEs/optical MEMS devices or interferometry – include refractive optical elements (ROE) such as optical lens, beam splitter, birefringent plates etc. Simulation tools like MATLAB, Python, Lumerical FDTD, Comsol Multiphysics, Coventorware OSLO etc. are used as well.