! SPOTDIA1

! This macro uses Point Spread Function data to compute the
! DIFFRACTION SPOT DIAMETER at the 1/e^2 points along the x-axis
! and the y-axis for various scan angles.  It also gives the 
! ellipticity of the spot and the spot diameter variation 
! (computed as a deviation from the average of all spot diameters
! in the scan field).  Each of the four 1/e^2 points (x,y) is 
! computed separately to preserve the information in the wing
! structure of the curve.  Written 1/98 by David Koren, II-VI, Inc.
! Revised 8/98.

FORMAT 15.3

title$ = $LENSNAME()
date$ = $DATE()
A$ = "DIFFRACTION SPOT DIAMETER"
PRINT
PRINT title$,"       ", date$
PRINT
PRINT A$
PRINT
PRINT "          CONFIG           SCAN ANGLE (x,y)          X AXIS         Y AXIS       ELLIPTICITY"
PRINT "                               degrees               microns        microns"
PRINT

SETVECSIZE 20000

bigx = 0
bigy = 0
smalx = 100000
smaly = 100000
nc = NCON()
FOR k = 1,nc,1
	SETCONFIG (k)

	GETPSF 0, 1, 2, 1

	np = vec1 (0)

	IF (np == 0)

		PRINT "PSF Computataion aborted."

		GOTO 1

	ENDIF

	IF (np == -1)
		PRINT "SETVECSIZE too small for PSF data."

		GOTO 1

	ENDIF 

	IF (np == -2)

		PRINT "Not enough system RAM for PSF data."

		GOTO 1

	ENDIF

! The exclamation point can be deleted from the PRINT statement below to print
! the values.

!PRINT "There are  ", np, " data points, spaced ", vec1 (np+1), "microns apart".

	nps = SQRT(np)

	ep = (nps/2)-1

	eq = ep*nps

	xdav=0.0

	jmax=0

	FOR i = 1, np, 1
		IF (vec1(i) > xdav)
			jmax = i
			xdav = vec1(i)
		ENDIF
	NEXT

! The exclamation point can be deleted from the PRINT statements below to print
! the values.

!PRINT "The position of the maximum x value is ", jmax

!PRINT "The maximum x value is ", xdav

! Computes the spot radius from the maximum X position to the left side 1/e^2 point.
! flt means 'fraction less than.'

	FOR i = jmax, jmax-ep, -1
		IF (vec1(i) > 0.135) & (vec1(i-1) < 0.135) 
			fltx=(vec1(i)-0.135)/(vec1(i)-vec1(i-1))
			srlx=(jmax-((i)-fltx))*(vec1(np+1))
		ENDIF
	NEXT

! Computes the spot radius from the maximum X position to the right side 1/e^2 point.
! fgt means 'fraction greater than.'

	FOR i = jmax, jmax+ep, 1
		IF (vec1(i) > 0.135) & (vec1(i+1) < 0.135) 
			fgtx=(vec1(i)-0.135)/(vec1(i)-vec1(i+1))
			srrx=((i+fgtx)-jmax)*(vec1(np+1))
		ENDIF
	NEXT

! Diffraction spot size (x) = spot radius left (x) + spot radius right (x).

	dssx=srlx+srrx

	ydav=0.0

	kmax=0

	FOR i = 1, np, 1
		IF (vec1(i) > ydav)
			kmax = i
			ydav = vec1(i)
		ENDIF
	NEXT

! The exclamation point can be deleted from the PRINT statements below to print
! the values.

!PRINT "The position of the maximum y value is ", kmax

!PRINT "The maximum y value is ", ydav


! Computes the spot radius from the maximum Y position to the left side 1/e^2 point.
! flt means 'fraction less than.'

	FOR i = kmax, kmax-eq, -nps
		IF (vec1(i) > 0.135) & (vec1(i-nps) < 0.135) 
			flty=(vec1(i)-0.135)/(vec1(i)-vec1(i-nps))
			srly=(kmax-((i)-(flty*nps)))*(vec1(np+1)/nps)
		ENDIF
	NEXT


! Computes the spot radius from the maximum Y position to the right side 1/e^2 point.
! fgt means 'fraction greater than.'

	FOR i = kmax, kmax+eq, nps
		IF (vec1(i) > 0.135) & (vec1(i+nps) < 0.135) 
			fgty=(vec1(i)-0.135)/(vec1(i)-vec1(i+nps))
			srry=((i+(fgty*nps))-kmax)*(vec1(np+1)/nps)
		ENDIF
	NEXT


! Diffraction spot size (y) = spot radius left (y) + spot radius right (y).

	dssy=srly+srry

	IF (dssx <= dssy)
		elip1 = (dssx/dssy)
		ellipt = elip1
	ELSE
		elip2 = (dssy/dssx)
		ellipt = elip2
	ENDIF

	PRINT CONF(), PAR3(3), PAR4(8), dssx, dssy, ellipt

	IF (dssx > bigx)
		bigx = dssx
	ENDIF

	IF (dssy > bigy)
		bigy = dssy
	ENDIF

	IF (dssx < smalx)
		smalx = dssx
	ENDIF
	IF (dssy < smaly)
		smaly = dssy
	ENDIF
NEXT

! The exclamation point can be deleted from the PRINT statements below to print
! the values.

!PRINT bigx,bigy
!PRINT smalx,smaly

IF (bigx >= bigy)
	smax = bigx
ELSE
	smax = bigy
ENDIF
IF (smalx <= smaly)
	smin = smalx
ELSE 
	smin = smaly
ENDIF

! The exclamation point can be deleted from the PRINT statement below to print
! the values.

!PRINT smax,smin

svar = 100*((smax-smin)/(smax+smin))

FORMAT 5.1

PRINT 
PRINT "          The spot diameter variation is +/-",svar, "%"
PRINT
PRINT "          The variation is computed as a deviation from the average"
PRINT "          of all spot diameters in the scan field."
LABEL 1