A. Mohammed

Recent applications of the electrooptic modulators in radio-over-fiber (ROF)

Design of electrooptic modulators in the applications of radio-over-fiber (ROF) has been studied and investigated in the present paper. Integrated optic design is handled to build a tank circuit to obtain the maximum output power. The modulated bandwidth is deeply and parametrically studied over wide ranges of the affecting sets of parameters via specially-designed software which processes the interaction of causes and effects. The design parameters of the tank circuit have been processed over large operating requirements. The output due to the nonlinear distortion has been also analyzed, and its penalty is computed. Crystal modulator made of Potassium Dihydrogen Phosphate (KDP) crystal is processed.

Performance characteristics of high speed laser diodes under thermal-irradiated operating conditions

In the present paper, the performance characteristics of high speed laser diodes (based on vertical cavity surface emitting laser (VCSEL) are deeply and parametrically investigated under thermal-irradiated operating conditions. The processed characteristics are: the harmonic response transfer function, the resonance frequency, 3-dB bandwidth, and the rise time. These diodes affect the transmitted bit-rate in high-speed advanced optical communication systems. The effects of both ambient temperature (and consequently the inner temperature), the injected current (power), and the dose of irradiation are deeply investigated. The pulse rise time and the resonance frequency as well as the 3-dB bandwidth are the major criterions of the device speed. Nonlinear relations are correlated to investigate the power-current and the voltage-current dependences of the devices.