TEMPERATURE COMPENSATING LONG PERIOD OPTICAL FIBER LATTICE FILTER

摘要

PURPOSE: An optical fiber lattice filter is provided to enable compensation of a coupling wavelength movement according to the temperature growth by re-coating a long period lattice with a material having a refractive index which increases according to the temperature growth. CONSTITUTION: A long period lattice(600) and a core(602) are surrounded by a cladding(604). The cladding where the long period lattice is formed is surrounded by a recording part(608). The recording part(608) is composed of a material having a refractive index which is smaller than that of the cladding(604) and increases according to the temperature growth. According to the cladding part(608), a coupling wavelength movement generated by the refractive index growth according to the temperature growth takes place in the opposite direction to a coupling wavelength movement according to the refractive index difference between the core(602) and the cladding(604).