Branch of physics dealing with the transmission of light and images through glass or plastic fibres known as optical fibres. Such fibres are now commonly used in both communications technology and medicine.
Blue expresses patriotism and noble ideas. Red denotes bravery. White symbolizes peace and purity. The stars stand for the three island groups: Luzon, the Visayan, and Mindanao. Effective date: 25 March 1936.