 Paraxial approximation

The paraxial approximation is an assumption used in optics, particularly in the study of lenses and geometric optics. It simplifies the analysis of light rays when they travel through optical systems. The fundamental idea is that light rays make small angles with the optical axis (the central line of the optical system), allowing us to use certain mathematical simplifications. ### Key Points of the Paraxial Approximation: 1. **Small Angles**: The approximation assumes that the angles involved are small.