In this paper the latest experimental results of a novel PW600 chiral nematic liquid crystal with significantly reduced temperature sensitivity of the selective Bragg reflection are presented. The PW600 liquid crystal was used to fill prototype photonic crystal fibers with 3, 5, 6 and 8 rings of the holes manufactured by MCSU, Lublin and temperature-induced photonic band gap shifts have been observed. Additionally, experimental results with a new low-birefringence nematic liquid crystal 1800B are presented. The results obtained suggest great potential of the liquid crystals filled photonic crystal fibers for optical fiber attenuators and modulators.