1Department of Physics;
Faculty of Science for Girls;
King Khalid University;
Abha;
KSA 2Department of Physics;
Aswan Faculty of Science;
Aswan University;
Aswan;
Egypt;
Department of Engineering Sciences;
Community College;
Umm Al-Qura University;
Mecca;
KSA;
Phase; Shifting; Interferomerty; Mechanical; Properties; Birefringence; PTFE; Fibres;