M.Sc Thesis

M.Sc StudentMalka Haim
SubjectControl of Passively Mode-Locked Optoelectronic
DepartmentDepartment of Electrical and Computer Engineering
Supervisor PROF. Moshe Horowitz
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Ultra-low jitter RF pulse train is important for communication system and for radars. One of the methods to generate RF pulse train is by using arbitrary waveform generator were the signal quality determine by the number of bits of the digital to analog converter and by the phase noise of the digital to analog converter clock.
In a previously work it was shown that passive mode locked Optoelectronic Oscillator can generate pulse train with low jitter less than 3 psec. However in that work the pulse shape and the pulse to pulse delay could not be controlled.

This work shows that when we use a photodiode with TIA (Trans-Impedance Amplifier) that operates in a saturation region instead of regular photodiode, we are able to control the pulse shape and the delay time between pair of the pulses by adjusting the applied bias of the Mach-Zehnder modulator.

By utilizing the extremely low jitter of the passively mode-locked OEO and the continuous control of the pulse shape and the pulse to pulse delay, the suggested system can be adopted to PWM (Pulse Width modulation) and to PPM (Pulse Position Modulation) modulators for RF and optic communication.