A new method to detect bacterial endospores and determine their concentration was demonstrated by the addition of a solution of terbium chloride to a suspension of bacterial endospores. The terbium chloride reacted with the calcium dipicolinate in the spore case to form terbium(III) dipicolinate anion. Solid particles, including residual bacterial particles, were removed by filtering. The photoluminescence from the solution was measured as a function of excitation wavelength, emission wavelength, and bacterial endospore concentration. The photoluminescence from terbium(III) dipicolinate anion in the solution was easily identified.

A determination of the viability of an endospore detection technique using terbium dipicolinate photoluminescence in the presence of other chemical and biological materials was performed. The compounds and organisms examined, possible environmental constituents, covered three broad categories:  organic compounds, inorganic compounds, and biological materials. Each substance was tested for a false positive, which occurs if the intrinsic terbium photoluminescence is enhanced in the absence of a bacterial endospore. The detection technique was also investigated for false negatives, which occur if a known positive endospore signal is inhibited significantly. Although several materials may give rise to false negative signals, none caused a false positive signal to be observed.

A novel technique in time resolved luminescence spectroscopy called population mixing using a subpicosecond cw mode-locked dye laser has been developed and applied to p-type GaAs at low temperatures. Using this technique the relaxation lifetime for electron recombination was measured to be 39±7 ps for p-type GaAs with Zn at 6×1018 cm−3 hole concentration. This is comparable to the relaxation time measured by a streak camera.