The invention discloses a tunable frequency doubled
optoelectronic oscillator device based on
phase modulation, relates to the technical field of a
microwave and the technical field of
optical communication, and is mainly applied to generation of a
microwave local oscillator signal. The method is as shown in attached graphs. The device comprises a
laser source, polarization controllers, a
circulator, a
polarization beam splitter, a phase modulator, an
optical coupler, polarizers, a standard single mode
fiber, optoelectronic detectors, a tunable bandpass filter, an electric
amplifier and an electric phase shifter. The phase modulator is characterized in that modulation is carried out in a forward direction and is not carried out in a backward direction. An optical
signal output from the
circulator is split into two ways of signals with equal power through the
optical coupler. One way is fed back to the phase modulator to form an
optoelectronic oscillator, thereby obtaining a
fundamental frequency signal. According to the other way, an optical carrier is inhibited by adjusting the
polarization controller, thereby obtaining a frequency doubled
microwave signal. Through combination of the tunable bandpass filter, the frequency doubled microwave signal with tunable frequency can be obtained. According to the
optoelectronic oscillator, the frequency tuning range is relatively large, the
phase noise is relatively low, and moreover, the
fundamental frequency oscillator signal and the frequency doubled microwave signal can be obtained. The scheme is simple in structure and flexible in adjustment and is not influenced by bias
voltage drift in a traditional strength modulation scheme.