2012-07-17Tutorial Zemax Introduction 11Introduction11.1Exercise 1-1:Stair-mirror-setup.1.2Exercise 1-2:Symmetrical 4f-system1 Introduction1.1Exercise 1-1:Stair-mirror-setupSetup a system with a stair mirror pair,which decenters an incoming collimated ray bundle with 10 mmdiameter by 40 mm in the-y direction.The wavelength of the beam is=632.8 nm.After this pair of mirrorsa decentered main objective lens with focal length f=200 mm made of BK7 is located 25 mm below theoptical axis and focusses the beam.a)setup the systemb)generate layout drawings in 2D and in 3Dc)calculate the beam cross section on the second mirror,what is the size of the patternd)determine the optimal final sensor plane location.Calculate the spot of the focussed beam.Discuss thee)now extend the separation between the two mirros to 200mm.The system now should be modified tohave an intermediate focal point in the midpoint between the mirrors.Calculate the radii of the mirrors torecollimate the beam before the refractive lens.Determine again the best image plane.If the spotdiagram is considered,what is the reason for the drastic changeSolution:a)The best way to introduce the folding mirror is to used the option 'add folding mirror'.Here two explicitesurfaces of the type coordinate break are introduced before and after the surface with a pickup of theangles.The idea ist to:1.change the orientation by 45to get the local coordinate system of the mirror befor the surface2.mirror operation,the help function automatically introduces negative thicknesses behind the first mirror3.perform the second 45 rotation to get the final 90-axis orientation of the propagation axis after the mirror4.fixe the next distance (negative after the first mirror)aftre that second coordinate breakIn princple,it is also possible to use the local coordinate changes of a surface.But this does not allow forgeneral pickups,optimization etc.and is more cumbersome to change.Furthermore the input data are notseen in the lens data editor.To setup a lens with a pregiven focal length,there are several possibilities.An optimization of one of thesurface radii with a focal length requirement in the merit function (EFFL,target value 200)is one generaloption.In addition,the first surface can be fixed and the second surface is obtained by the program with asolve,that forces the element power to be F=1/f =0.005.Unfortunatelly,this doen't work with the firstsurface.The system could be setup in the following scheme:2Lens Data EditorG1aSen1-Diam..Par 0(unu..Decenter X Decenter Y Ti1t AbouStandardInfinity0.000001 Standad30.000010.00000.000000.000000.000000.000000.00000=45.00090.000000,00000Coordi..-40.0000.00000-45.00050.000000.000000.00000-25.00045.0000205.00015.0000BK750.00000.00000-205.0050,00000,000001.307980,00000b)c)Footprint:the size of the beam in the local system is Dx=20 mm,Dy 28.3 mmAperture Diameter:36.0000Footprint Diagram3d)The final image location is determined by the quick focus option.The spot has a typical coma-shapedstructure due to the off-axis usgae of the lens.e)The modified data are now with the radii-282 mm and +282 mm(due to the change of sign by the firstmirror)respectivelyLens Data EditorEdit Solves View HelpCommentSemi-DiameterOBJStandardInfinityInfinity0.00000001StandardInfinity30.000000010.00000002Coordinate .0.00000000.0000000Standard-282.00000000.0000000MIRROR18.0000000U-200.00000000.00000000.00000000.0000000Standard282,00000000,0000000MIRROR18.0000000可7 Coordinate .30.00000000.0000000Standard205.000000015.0000000BK750.0000000UStandard-205.000000097.560515550.0000000UIMAStandard14.1430211The layout and the spot diagram looks as follows: