This book connects the dots between geometrical optics, interference and diffraction, and aberrations to illustrate the development of an optical system. It focuses on initial layout, design and aberration analysis, fabrication, and, finally, testing and verification of the individual components and the system performance. It also covers more specialized topics such as fitting Zernike polynomials, representing aspheric surfaces with the Forbes Q polynomials, and testing with the Shack–Hartmann wavefront sensor. These techniques are developed to the point where readers can pursue their own analyses or modify to their particular situations.