! Written by Boyd V. Hunter, Sept. 13, 1999
!
! This macro determines the optimal refractive index values to use
! when AR coating a GRADIUM lens (front and back surfaces).
! If the lens is a doublet, the front surface is the cemented interface,
! even though that surface will not be AR coated.

! The optimal index is the index at 70% of the clear aperture.

INPUT "Which surface is the front of the GRADIUM lens?", front
back=front+1
Input "What is the clear aperture diameter on this lens?", CA
Input "Which wavelength do you want to use? (0=default wavelength)", wlno
if wlno==0 then wlno=PWAV()


FORMAT .0
	GETSYSTEMDATA 1
	TC=THIC(front)
	TITLE$=$COMMENT(front)
	R70=0.35*CA
	SAG1=SAGG(0,R70,front)
	SAG2=SAGG(0,R70,back)
	TC2=TC+SAG2
	S1V=GRIN(front,wlno,0,0,0)
	S170=GRIN(front,wlno,0,0,SAG1)
	S2V=GRIN(front,wlno,0,0,TC)
	S270=GRIN(front,wlno,0,0,TC2)
	
FORMAT .4
	PRINT TITLE$
	PRINT "WAVELENGTH: ", WAVL(wlno)
	PRINT "FRONT SURFACE INDEX: ", S170
	PRINT "BACK SURFACE INDEX: ", S270