Spectroscopy of low Rydberg n$p$ states of $^{7}$Li

Laser-induced florescence spectroscopy of an atomic Lithium beam has been performed and the absolute energies of the n$p$ atomic states with $8\le n\le 15$ have been measured. The atoms are excited to these states by a total of four narrow bandwidth frequency-stabilized diode lasers. We review the experimental apparatus and techniques used to excite these states and present their absolute energies, which are an order of magnitude more precise than previous measurements. We compute the quantum defects of the states and compare them with recent theoretical calculations. The agreement is excellent.