A print-out of the "variable sheet" is shown below. It lists each variable in the model and the units in which its value is displayed. Additionally, alternative units for each variable are given in parentheses in the Comments column. The relationships between the units are defined by the Unit sheet (not shown).

--------------------------------------------------------------------------------------- St Input Name Output Unit Comment 200 lambda nm wavelength of light (nm, A, µm, cm) freq 1.5E15 Hz frequency (Hz) E 143.24584 kcal/mole energy (Joule, erg, eV, kcal/mole) v 50000 cm-1 wavenumber (cm-1) f 8.3333333 cm focal length of lens (cm, m, in) 16.666667 S1 cm source to lens distance (cm, m, in) S2 16.666667 cm lens to image distance (cm, m, in) M 1 Magnification factor 1.6 n refractive index of lens material 10 R1 cm radius of curvature 1 (cm, m, in) 10 R2 cm radius of curvature 2 (cm, m, in) 1 A cm2 area of lens (cm2, mm2) D 1.1283796 cm diameter of lens (cm, m, in) omega .0036 steradian solid angle collected (steriadians) Fnumber 14.770443 effective F-number of optical system Flens 7.3852213 F-number of lens itself .01 Bs W/Sr-cm2 source radiance (watts steradian-1 cm- 1 As mm2 Source area viewed (cm2, mm2) Phi .00000036 W Light flux incident on lens (watts) Ai .01 cm2 effective area of image of source Ei 3.2268E-5 W/cm2 Image irradiance (watts/cm2) FotFlux 3.6221E11 Photon flux (Photons/sec) on lens ImgFlux 3.2466E11 Photon flux (Photons/sec) at image rho .05325444 reflectance of one air interface Tf .89632716 Overall transmittance of lens ---------------------------------------------------------------------------------------This is the Rule sheet. It gives the equations that define the relationships between the variables.

S Rule * lambda = 1/v ' Definition of wavenumber * E = (6.626E-34)*freq ' Energy of photon * freq = (3E10)/lambda ' speed of light = 3E10 cm/sec * 1/f=(1/S1)+(1/S2) ' Thin lens equation * M=S2/S1 ' Magnification = (image length)/(source length) * 1/f=(n-1)*(1/R1+1/R2) ' Lensmaker's equation * A=3.14159*(D/2)^2 ' Definition of area * omega=A/S1^2 ' Definition of solid angle * Fnumber=S1/D ' Definition of "F" number of system * Flens=f/D ' Definition of "F" number of lens * Phi=Bs*omega*As ' Relation between flux and radiance * Ai=As*M^2 ' Image area (cm2) * Ei=Tf*Phi/Ai ' Image irradiance, including reflectance loss * FotFlux=Phi/E ' Photon flux incident on lens * rho=((n-1)/(n+1))^2 ' Reflectance at normal incidence * Tf=(1-rho)*(1-rho) ' Overall transmission of two surface/air boundaries * ImgFlux=Tf*FotFlux ' Photon flux at image, including reflectance loss ---------------------------------------------------------------------------------------Download the Simple Lens model.

2. For each known quantity:

- a. Under the "units" column, enter the units in which you intend to use
for that variable, if different from the units already there.
- b. Under the "input" column, type in the value of that quantity.

[RETURN] to Chem 623 home page.

T. C. O'Haver, Chem 623, 1994