The construction of a diode laser polarimeter apparatus by undergraduate students is described. The construction of the modular apparatus by undergraduate students gives them an insight into how it works and how the measurement of a physical or chemical property is conducted. The students use the polarimeter to obtain rotation angle values for the acid hydrolysis of sucrose, which are in good agreement with values obtained by a commercial instrument and those reported in the literature. The kinetic constant of the classic chemical reaction of the sucrose inversion in various experimental conditions is also obtained. (Contains 1 table and 2 figures.)