The Theoretical Analysis of Uniform FBG Local Transverse Force Characteristics

In this paper,the transveral force on uniform FBG is specially analyzed according to the couple-mode theory and the corresponding mathematical model is established. Studies show that when the FBG under local transverse force, the length of pressure has no effect on the reflection spectrum. The wavelength of the reflection spectrum splitting point and lateral force possessed a direct proportional linear correlation, and has periodicity at the same time. The split point reflectivity and the force position approximately have hyperbolic tangent relationship.

DFB Lasers with Tilted Waveguide for Multi-Wavelength Generation

In this paper, we present the theoretical investigation of index-coupled distributed feedback (DFB) laser with tilted single mode ridge waveguides. By tilting part of the ridge waveguide in various degrees, DFB laser with manifold effective grating periods can be realized. The structure is analyzed using couple mode theory in matrix form based on threshold analysis. Important parameters of DFB laser like resonant frequency and threshold gains are obtained by solving the eigen-equation. The results indicate not only that the lasing frequency is modulated by the waveguide titling angle, but also large Gain Margin (GM) can be achieved at the threshold condition which enhance the stable single mode operation in index-coupled DFB laser.