US 12,449,351 B1
Method of determining absorption and extinction coefficient of prism shaped material
Ronald A. Synowicki, Lincoln, NE (US)
Assigned to J.A. WOOLLAM CO., INC., Lincoln, NE (US)
Filed by Ronald A. Synowicki, Lincoln, NE (US)
Filed on Apr. 24, 2023, as Appl. No. 18/445,134.
Claims priority of provisional application 63/338,231, filed on May 4, 2022.
Int. Cl. G01N 21/27 (2006.01); G01N 21/25 (2006.01); G01N 21/41 (2006.01)
CPC G01N 21/255 (2013.01) [G01N 21/27 (2013.01); G01N 21/4133 (2013.01); G01N 2201/061 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method of quickly determining absorption and extinction coefficient of a sample having a front (F) and a back (B) side, said front and back sides being substantially planar but are not parallel to one another, said method comprising the steps of:
a) providing a sample having a front (F) and a back (B) side, said front and back sides each being substantially planar but are not parallel to one another;
b) providing:
a source of a beam of electromagnetic radiation that comprises at least one wavelength which is subjected to absorption in said sample when caused to enter and pass therethrough; and
a detector of electromagnetic radiation which is sensitive to the at least one wavelength provided said source thereof;
c) positioning said sample and said source of a beam of electromagnetic radiation such that in use a beam of electromagnetic radiation from said source thereof is caused to enter the front side thereof, pass therethrough, exist the back side thereof, and enter said detector;
d) while causing the location at which said beam enters said sample to move along a path transversing the front side of said sample by moving said beam and/or said sample such that electromagnetic radiation entering said detector continually increases, or continually decreases as said path is traversed, obtaining a data set relating beam intensity vs. beam position on said sample along said path;
e) conducting a mathematical regression of an equation:
I=I0 exp(−az),
where a=(4 Pi k)/λ, I0 is an initial beam intensity, λ is wavelength, and k is the extinction coefficient;
onto said data set to the end that the absorption and extinction coefficients are determined.