  Randomness is fundamental in quantum theory, with many philosophical and
practical implications. In this paper we discuss the concept of algorithmic
randomness, which provides a quantitative method to assess the Borel normality
of a given sequence of numbers, a necessary condition for it to be considered
random. We use Borel normality as a tool to investigate the randomness of ten
sequences of bits generated from the differences between detection times of
photon pairs generated by spontaneous parametric downconversion. These
sequences are shown to fulfil the randomness criteria without difficulties. As
deviations from Borel normality for photon-generated random number sequences
have been reported in previous work, a strategy to understand these diverging
findings is outlined.
