The theoretic transfer function of the filter made of N stage HBFs, and the expression are obtained when N is 1, 2 or 3; the polarization independence of the filter is analyzed, and the relation between the frequency response and the parameter of filter such as the length, beat length of HBFs and the angles between HBFs is studied; finally, some experimen.

Then the polarization independence of nonreciprocal waveguide was realized.

A novel structure of polarization independent, in line magnetic optical isolator was presented.

A novel configuration of 2×2 all optical polarization independent bidirectional fiber optical switch is presented.

Study on structure of polarization dependent isolators;

MOVPE growth of 1310nm polarization-insensitive strained quantum-well semiconductor optical amplifiers;

Study on 1.55μm AlGaInAs-InP polarization-insensitive semiconductor optical amplifier and its temperature characterizatics;

A polarization-insensitive multiple-quantum-well optical amplifier with integrated spot-size converter for 1.

To measure isolation、 insersion loss、 bandwidth、 connection loss and return loss of polarization-independent isolator with fiber connectors at both ends, the methods which utilize light power meter and spectrometer are given.

In this thesis, from the view of application, we study the properties of the tunable photonic crystals, polarization-independent photonic crystals and the photonic quantum-well structures containing negative-index materials.