HP35S Fraunhofer Diffraction - Spherical

HP35S Fraunhofer Diffraction - Spherical
Source: HP 67/97 Optics Pac, June 1978

This version takes advantage of the HP's integral function. The trade off is that two labels are required. On the plus side, this program can be typed directly into a 32Sii or 33S.

Labels: F (Main), G (Integral)

Variables:

D = diameter in microns (10^-6 meters)
L = wavelength of light in microns (10^-6 meters)
A = θ, angle of the slit, entered in degrees

Formulas:

X = π D ÷ L
W = X sin A
J = int(cos(T - W sin T) dT, 0, π)/π
I = (X^2 J ÷ W)^2

Output:

Bessel function of the first kind (J) - paused for 2 seconds;
Fraunhofer Intensity (I) - dimensionless - as I understand it, this is how intense the diffraction is

Programs:

LBL F
INPUT D
INPUT L
÷
π
*
STO X
INPUT A
→RAD
STO A
SIN
*
STO W
RAD
0
π
FN= G
∫ FN dT
STO J \\ Bessel store in J for future use, if desired
PSE
PSE
RCL ÷ W
RCL X
x^2
*
x^2
RTN

LBL G
COS(T-W*SIN(T))/π \\ enter as an equation (press [EQN])
RTN

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This blog is property of Edward Shore. 2013