Survey

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Survey

Document related concepts

no text concepts found

Transcript

Midterm exam OPTI 518 Spring 2015 You can use a computer, a calculator, your class summary, and your class notes. 75 minutes. In answering the questions below write down the pertinent formulas and show how you use them to do the calculations. Each question is worth 10 points for a total of 100. Provide labeled graphs and sketches whenever asked. 1) Draw the wavefans for a system having 5 waves of spherical aberration and -10 waves of astigmatism. Draw the sagittal and tangential fans for the zero field position and the 0.707 field position. 2) Write down the relationship between a change of focus W020 and the longitudinal change Z ' . For a f/10 system with W020 1 , what is Z ' ? The wavelength is 0.0005 mm. 3) Write down the sag equation to fourth-order for a spherical surface of radius r and semi-aperture y. 4) A thin, equi-convex, lens in air is made out of BK7 glass, has a focal length of 100 mm and works at F/5. The stop aperture is at the lens and the full field of view is 48 degrees. Determine the Lagrange invariant, the image height, and the chromatic aberrations. 5) For the lens in problem 4 what is the amount in waves (1 wave = 0.0005 mm) of spherical, coma, and astigmatism aberrations? 6) For the lens in problem 4 what is the Petzval radius? What is the amount of distortion aberration? 7) For the lens in problem 4 design an aspheric surface on a parallel glass plate that corrects only for spherical aberration. This aspheric plate has zero optical power. Where should the aspheric plate be located? and what is the sag of the aspheric profile of the plate? Assume the index of the plate to be n=1.5. Sketch the system. 8) For the system in problem 7 add a field flattener lens to correct for Petzval field curvature. What is the power of the field flattening lens? Sketch the plate, lens and field flattener system. Sketch the field curves. 9) A point source of light is at the bottom of a swimming pool which has a depth of 3350 mm. The light is then collected by a lens with an aperture of 2000 mm located at 5000 mm above the swimming pool. Using an index of refraction for water of 1.33, determine how much spherical aberration the water-air interface is introducing. 10) Provide the amount of defocus for minimum wavefront variance, to reach the minimum circle, and for minimum spot size in the presence of five waves of positive spherical aberration.