While useful, indirect techniques provide limited insight into the chemical makeup of a photopolymer system in real time. For example, photo-rheology is limited by merely monitoring the change in physical properties of a forming polymer, while photo-differential scanning calorimetry measures only the heat produced during the reaction. On the other hand, direct measurements of molecular populations, such as FTIR, are capable of probing polymerization kinetics in real-time. Unfortunately, FTIR often suffers from poor measurement resolution. Even relatively simple molecules have numerous IR-active vibrational modes which overlap due to thermal broadening.