Lambert’s cosine law states that the radiant intensity from the ideal diffusely reflecting surface and cosine of the angle θ between the direction of incident light and surface normal are directly proportional. Mathematically,E (illumination from a surface) ∝ Cos ƟWhen a surface is radiating as a result of being illuminated by an external source, the irradiance (energy or photons ...read more

Chromaticity is a property that characterizes the color quality of an object seen by the human eye and gives a measure of how well an object is seen by the human eye. It is independent of the brightness and so is different from luminance where brightness is indicated. It can be determined by the spectral content of light. Light sources with the same chromaticity indices will emit identically color...read more

Beer-Lambert's law is a combination of Lambert's law (1730) and Beer's law (1850), which governs the light radiation absorption by molecules at low concentrations. Beer-Lambert law relates to the attenuation of light on passing through a physical material containing attenuating species of uniform concentration. The absorption of light is also directly proportional to the optical path l...read more

Mode Mixing in LasersMode Mixing in Lasers refers to a phenomenon in which the laser output does not have a single well-defined spatial mode, but rather exhibits a mixture of different spatial modes. It leads to decreased performance and causes potentially damaging effects in lasers. Therefore, it is essential to prevent mode mixing for optimizing laser performance and ensuring safe operation.In a...read more

The electromagnetic spectrum is defined as the distribution of a number of electromagnetic waves as a function of wavelength, frequency, or wave number. The EM wave exhibits both wave-like and particle-like properties. The behaviour of the longest wavelengths is dominated by wave characteristics, whereas the behaviour of the short wavelengths X-rays and gamma rays is dominated by photon aspects, y...read more

In optics, the ABCD law is a fundamental principle used to describe the behavior of light rays as they pass through optical systems. This law provides a simple and powerful way to analyze the propagation of light through complex optical systems, such as lenses, mirrors, and other optical components. The ABCD law is essential for designing and optimizing optical systems used in a variety of ap...read more

Colorimetry is the science that deals with quantifying and measuring color. It helps to express color numerically which makes it easy to compare. Chromaticity gives a qualitative measure of the colors as seen by the human eye whereas colorimetry gives a numerical measure. The same color may be expressed differently by each person depending on their age, illumination, sample size, background effect...read more

The Doppler shift is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the source of the wave. The Doppler effect is the phenomenon that causes this change in frequency or wavelength. It is named after Austrian physicist Christian Doppler, who first described it in 1842. The effect can be observed with sound waves, light waves, or any other type o...read more

The Kerr effect is a phenomenon that occurs when a material's refractive index changes in response to an electric field. The Kerr effect was discovered by a Scottish physicist named John Kerr in 1875 and it was named after him. This effect is a type of electro-optic effect, which refers to the interaction between light and an electric field. When a strong electric field is applied to a tr...read more

Pockels Effect is the linear electro-optic effect in which the refractive index of the medium is modified with respect to an applied electric signal or voltage. This effect was discovered by the German physicist Friedrich Pockels in 1893. It occurs only in non-centrosymmetric crystals, i.e., crystals with inversion symmetry. Lithium niobate (LiNbO3), lithium tantalate, potassium dihydrogen phospha...read more

Ray theory of propagation is a simplified approach used to analyze how light waves propagate and transmit through the fiber. According to the theory, light travels through the fiber in the form of rays, following a straight path along the axis of the fiber, and obeys laws of geometrical optics. It is used to get a clearer picture of light propagation along a fiber and approximate optical fibers...read more

Bragg's Law is a fundamental principle in physics that explains how X-rays and other types of electromagnetic radiation can be used to determine the structure of crystals. Bragg’s Law is used to calculate the angles at which X-rays are diffracted by a crystal to determine the positions of atoms within the crystal lattice. This law was put forward by Sir William Lawrence Bragg and his fat...read more