2012-11-28Prof.Herbert GrossFriedrich Schiller University JenaInstitute of Applied PhysicsAlbert-Einstein-Str 1507745 JenaExercisesLecture Optical design with Zemax-Part 44Aberrations4.1 Strehl ratio and geometrical vs diffraction Psf spot sizeA single lens made of K5 with focal length f 25 mm and thickness d 5 mm is illuminated by adiverging beam with numerical aperture NA 0.1.After the lens the light should be collimated.If thecollimated beam is refocussed without further aberrations,the point spread function is not diffractionlimited.a)Calculate the accurate Strehl ratio,the estimated Strehl ratio and the geometrical and diffractionencircled energy inside the ideal Airy diameter.b)If now the numerical aperture is reduced,the Marechal estimation becomes better.Calculate thelargest NA,for which the relative error is smaller then 2%.What amount for geometrical anddiffraction encircled energy is inside the Airy diameter is obtained here4.2 Aberrations and Performance of an Diode CollimatorLoad the lens GLC-6.5-8.0-830 DIODE LASER COLLIMATING LENS from the catalog of CVI MellesGriot.a)What is the numerical aperture of the lens in the image?Determine the Strehl ratio and comparethe estimated and the exact value.b)What are the two surfaces with the largest contribution to the spherical aberration The first lensgroups looks like an achromate.Comresponds the correction of this part of the system to anachromatec)Show,that all intersection points of the spot diagram are inside the Airy diameter.If the spot isanalysed it is seen,that there is a bright kemel with a surrounding halo.What is the relative powercontent of the inner kernel region What is the diameter of this inner partd)What is the image contrast of a grating object with 100 line pairs per millimeter of this systemDetermine the MTF of the lens for defocussing.What is the depth of focus intervall,where inside thecontrast is larger than 50%?Explain the asymmetry of the curve.4.3 Anamorphotic Diode collimatorA semiconductor diode with wavelength 650 nm and the divergence aperture values 0.4/0.1 in thefast ans slow axis respectively should be collimated in a circular beam with a diameter ofapproximarely 8 mm.The collimated beam is now focussed into a fiber with numerical aperture of NA=0.1.1/22diodecircular beamNAy=0.4D=8 mmL4NAx=0.1L2cylindrical lensfocussing lens1=650nmfiberNA=0.1L1L3asphericalcylindrical lenscollimatorFind a solution for this problem with only available catalog lenses.Is the setup diffraction limited Explain the shape of the residual spot pattern.What are the reasonsfor the residual aberrations in the system What can be done to further improved the resultDiscuss possible steps to get a shorter system.What are the consequences of a compact layout