The following program is under the GNU General Public License (GPL).

本作品为自由软件，您可以依据自由软件基金会发行的GNU通用公共许可证第2版或任意后续版本的条款，传播和/或修改本作品。本作品发表时预期有用，但对此无任何保证，亦无隐含的可以销售或适合特定目的的保证。详情请见GNU通用公共许可证第2版和第3版。http://www.gnu.org/licenses/gpl.htmlGPLGNU General Public Licensetruetrue

; Program Written in IDL (Interactive Data Language) ; Free Interpreter availible at www.rsinc.com ; Written by Georg Wiora ; This Program is under the  GNU General Public License (GPL)   ; ; Create a display of interference patterns ; Save this text as file "Interference2.pro" to run it.   ; Draw a circle PRO circle,x,y,r,_REF_EXTRA=ex   n=ULONG(!DPI*r) > 1   phi = FINDGEN(n)/FLOAT(n)*2*!DPI   x1 = r*COS(phi)+x   y1 = r*SIN(phi)+y   PLOTS,[x1,x1[0]],[y1,y1[0]],_STRICT_EXTRA=ex END  ; Compute the interference PRO Interference2    ; Final Image Size   siz=2000   ; No display if larger than 800x1600 pixel   pixmap=SIZ GT 800   ; Wavelength in Pixel   lambda=160   ; Half distance of the sources   dhalb = lambda    ; Compute the distance of each point in an array from the   ; center point: This is the phase of the signal   d1 = SHIFT(DIST(siz*2,siz),siz,siz/2)   ; Sinus of distace with 0 LE amplitude LE 2   f = SIN(d1/lambda*2*!DPI)+1   ; Compute Interference   inter = SHIFT(f,-dhalb,0)+SHIFT(f,dhalb,0)   ; Get maximum and minimum   ma = MAX(inter,MIN=mi)   ; Two colors are reserved for marking, the rest is gray scale   ; Scale interference to byte range [0..253]   inter = BYTE((TEMPORARY(inter)-mi)/(ma-mi)*253)    ; Use lookup table to display   DEVICE,DECOMPOSED=0   ; Gray scale   LOADCT,0   ; Half length of center cross bars in pixel   cs=30   ; Half width of center cross bars in pixel   cb=3      ; Set mark for center   ; Horizontal left   inter[siz-dhalb-cs:siz-dhalb+cs, siz/2-cb:siz/2+cb] = 254   ; Vertical left   inter[siz-dhalb-cb:siz-dhalb+cb, siz/2-cs:siz/2+cs] = 254   ; Horizontal right   inter[siz+dhalb-cs:siz+dhalb+cs, siz/2-cb:siz/2+cb] = 255   ; Vertical right   inter[siz+dhalb-cb:siz+dhalb+cb, siz/2-cs:siz/2+cs] = 255    ; Open a visible or invisible window (depends on pixmap flag)   WINDOW,XSIZE=2*siz,YSIZE=siz,PIXMAP=pixmap   ; Display the interference (only gray scale!)   TV,inter   ; Draw circles on maximum locations      FOR i=0,2.5*siz/lambda DO $   BEGIN     ; Maximum location left     circle,siz-dhalb,siz/2,(i+0.25)*lambda,THICK=6,/DEVICE,COLOR=254     ; Maximum location right     circle,siz+dhalb,siz/2,(i+0.25)*lambda,THICK=6,/DEVICE,COLOR=255   ENDFOR    ; Colortable 0-253 as gray scake   r = FINDGEN(256)/253*255   g=r   b=r   ; 254 is green   r[254]=0   b[254]=0   g[254]=255   ; 255 is red   r[255]=255   b[255]=0   g[255]=0    ; Read image from display   im=TVRD()   ; Crop invalid borders   im = im[siz/2:3*siz/2-1,*]    ; Save as PNG with colortable   WRITE_PNG,'Interference2.png',im,r,g,b   ; Convert to truecolor and write JPEG   imt = [[[r[im]]],[[g[im]]],[[b[im]]]]   ; smooth image a little bit (saves bandwith in jpeg and is OK   ; with high resolution)   imt[*,*,0] = SMOOTH(imt[*,*,0],3,/EDGE_TRUNCATE)   imt[*,*,1] = SMOOTH(imt[*,*,1],3,/EDGE_TRUNCATE)   imt[*,*,2] = SMOOTH(imt[*,*,2],3,/EDGE_TRUNCATE)   ; Write as jpeg   WRITE_JPEG,'Interference2.jpg',TEMPORARY(imt),/PROGRESSIVE,$              QUALITY=90, TRUE=3  END