This paper reports on the writing of long period gratings (LPGs) in a six-ring pure silica solid core, and large mode area photonic crystal fiber (fiber core diameter = 10.1 μm) using a CO2 laser system, and the characterization of their strain and temperature sensitivities. Temperature and strain sensitivities in the order of –19.6 pm/℃ and –88 pm/μm, respectively, were obtained, which were comparable or surpassed values of the similar photonic crystal fiber (PCF)-based LPG or sensor configurations found in the literature.