Addressed fiber Bragg structures in quasi-distributed microwave-photonic sensor systems

The article describes the theory and technique of addressed fiber Bragg structures and a new class of microwave-photonic sensory systems based thereon, the distinctive feature of which is that the fiber Bragg structure forms two ultra-narrowband frequency components separated by a unique address frequency spacing. The offset of the central frequencies of the Bragg structures is determined via processing a beat signal of the address frequencies on the photodetector, with its parameters making it possible to evaluate the physical fields applied. We formulate and solve a problem of unambiguously determining the central (Bragg) frequency shift of the addressed fiber Bragg structures with unique address frequencies and the same Bragg frequency. These are then combined into a single multi-sensor system with multiplexed response reception on a single photodetector.

Simulation of the Optimized Structure of a Laterally Coupled Distributed Feedback (LC-DFB) Semiconductor Laser Above Threshold

In this paper, the laterally coupled distributed feedback semiconductor laser is studied. In the simulations performed, variations of structural parameters such as the grating amplitude a, the ridge width W, the thickness of the active region d, and other structural properties are considered. It is concluded that for certain values ​​of structural parameters, the laser maintains the highest output power, the lowest distortion Bragg frequency δL and the smallest changes in the wavelength λ. Above threshold, output power more than 40mW and SMSR values greater than 50 dB were achieved.

Well Potential of Bright Solitary Wave in Fiber Bragg Grating

We proposed the formation of well potential of bright solitary wave in fiber Bragg grating. The study has been successfully performed out under Bragg resonance condition where the initial frequency of the light has the same value with the Bragg frequency. The Stokes parameter provides important information on the total energy and energy differences between the forward and backward propagating modes. The nonlinear parameter in this study was initially set to α = 1.0 and -1.0, β = 0.7 and γ = 0.1.