Matrix optics is a technique for tracing paraxial rays. The rays are assumed to travel only within a single plane so that the formalism applies to systems with planar geometry and meridional rays in circular symmetric systems. A ray is described by its position and its angle with respect to the optical axis. These variables are altered as the ray travels through the system In paraxial approximation, the position and angle at the input and output planes of an optical system are related by two linear algebraic equations. Consequently, the optical system can be described by a matrix. Construct the matrices of some optical components such as the transmissions through free space, a thin lens, and reflection by a spherical mirror. Also, explain the cascade system by using the ray-transfer matrix method.