1. R. J. Araujo, Appl. Opt. 7, 781 (1968).APOPAI0003-6935
2. R. J. Araujo, Photochromic Glasses, edited by G. H. Brown (Wiley, New York, 1971), pp. 667–686.
3. R. J. Araujo, US Patent 3,325,299 (1967).
4. The more appropriate form of this equation would be the three‐dimensional spherical coordinate equation ρt = (D/r)(rρ)rr+kI(A0− ∫ 0Rρdr)δ(r−r1), with the absorption defined as the integral of ρ over all separation distances r: A = ∫ 0Rρdr. The solution of the above equation for ρ(r,t) converges extremely slowly making it inconvenient to evaluate. We have found that the one‐dimensional approximation follows the exact form close enough for our purposes.
5. R. F. Reade and D. S. Martin, J. Appl. Phys. 31, 1965 (1960).JAPIAU0021-8979