Recovery process of optical stopping effect in tin or phosphorus-doped amorphous As2S8 thin-film waveguide.

In this research, the recovery process of the optical stopping effect on an amorphous arsenic sulfide thin-film waveguide is studied, both on the net As(2)S(8) and doping As(2)S(8) waveguide. Based on the experimental results, we analyzed the chemical bond structure of the samples. The hybrid orbital theory and electron energy bandgap theory are applied in order to establish the model of optical stopping and the recovery process. The numerical analysis results are well matched with the experiment data, which indicates that the model properly explains the optical stopping effect phenomenon. The model also can be applied to predict the recovery process of the optical stopping effect.

Fabrication and propagation characterization of As2S8 chalcogenide channel waveguide made by UV irradiation annealing.

Changes in the refractive index of amorphous chalcogenide As2S8 films upon ultraviolet (UV) exposure and annealing at different temperatures are investigated in detail, indicating an index contrast of the order of 10(-2) in the As2S8 channel waveguide. An As2S8 channel waveguide is fabricated using UV well irradiation and then annealing near the glass transition temperature and shows a low propagation loss of 0.76 dB/cm and good propagation characterization at the 1310 nm guided mode.

Automatic waveguide-fiber coupling system based on a multiobjective evolutionary algorithm.

A method for the automated alignment of optical waveguides and fibers based on a multiobjective evolutionary algorithm is proposed. This algorithm reduces the number of parallel operations considerably compared to previous automation schemes. The automated alignment of a single-core input fiber with a channel waveguide and a single-core output fiber is completed using this system in less than 3 min. The alignment of a single-core input fiber with a 1x8 splitter coupler and an eight-core output fiber array is completed in less than 10 min. These results demonstrate the effectiveness of the proposed scheme for automated waveguide alignment, substantially outperforming previous automatic alignment methods.

Optimized design of polarization-independent and temperature-insensitive broadband optical waveguide coupler by use of fluorinated polyimide.

A statistically optimized design method suitable for a polariation-independent and temperature-insensitive broadband waveguide coupler is proposed. By use of this method, a fluorinated polyimide waveguide 3-dB waveguide coupler for 1490 to approximately 1610 nm application is designed by optimizing polarization and temperature fluctuation. The validity of the design is verified through simulation based on the three-dimensional beam propagation method (3D-BPM), which revealed a coupling ratio of 50 +/- 0.8% in a 120-nm bandwidth in the temperature range -10 to 40 degrees C for both orthogonal polarizations.

Optimized design of fluorinated polyimide based interleaver.

Statistical optimization method for the design of a fluorinated polyimide wavelength division element for optical communication is proposed. The opitimized device is an interleaver element suitable for dividing over 40 wavelengths in the 1550 nm band. Optimization considers the inherent polarization dependence of fluorinated polyimide based on measurements of the dispersion characteristics and birefringence of fluorinated polyimide film. A 40-wavelength device is designed by use of the proposed technique for a working wavelength of 1550 nm and a wavelength interval of 0.8 nm. The device exhibited a 1-dB passband of 0.5 nm and a 3-dB passband of 0.8 nm, and output wavelength fluctuation due to polarization effects of less than 0.08 nm.

Optimized design of temperature-insensitive optical waveguide coupler with 120-nm bandwidth using fluorinated polyimide.

Method for designing optimized temperature-insensitive optical waveguide couplers by use of fluorinated polyimide is presented. Based on measured temperature and dispersion characteristics of fluorinated polyimide, a 3-dB waveguide coupler with a 120-nm bandwidth with minimal temperature variance is designed and verified through simulation based on three-dimensional beam propagation. The coupling ratio of the theoretical device is 50 +/- 0.7% in the waveband 1490 to approximately 1610 nm and the temperature range -10 to approximately 40 degrees C.