Cascaded microwave photonic filter-based photoelectric oscillator with tunable broadband

Abstract

The invention provides a cascaded microwave photonic filter-based photoelectric oscillator with a tunable broadband. The cascaded microwave photonic filter-based photoelectric oscillator comprises a first laser, a first polarization controller, a phase modulator, a first MPBF unit, a second MPBF unit, a first variable optical attenuator, a photodiode, an electric amplifier and an electric power divider which are sequentially connected, wherein a first output end of the electric power divider is used for outputting a generated microwave signal; a second output end of the electric power divideris connected with a radio frequency port of the phase modulator; when the photoelectric oscillator works, a phase modulation signal enters the first MPBF unit and then first mode selection is carriedout by using a single bandpass microwave photonic filter with the tunable broadband, thereby selecting an oscillation starting frequency of the OEO, and the phase modulation signal passes through thesecond MPBF unit and then auxiliary mode selection through an ultra-narrow bandwidth MPBF is achieved, thereby achieving single-mode oscillation starting of the OEO. A cascaded microwave photonic bandpass filter is utilized and combined with the OEO, so that single-mode oscillation starting of the OEO is achieved through multiple mode selection; and the broadband tenability of the OEO can be achieved through adjusting the central wavelength of the first MPBF unit.

Description

Technical field [0001] The present invention belongs to the field of optics and microwave technology, and more specifically, relates to a broadband tunable optoelectronic oscillator (Optoelectronic Oscillator, OEO) based on a cascaded microwave photonic filter. Background technique [0002] OEO uses low-loss optical fiber as the energy storage element, with its ultra-high spectral purity, broadband and high-frequency working potential and relatively simple structure and working conditions, it has become a very competitive high-end microwave / millimeter wave signal generator. . The basic structure of OEO was first proposed by X.Steve Yao and Lute Maleki in 1994. The main structures include lasers, electro-optic modulators, long optical fibers, photodetectors, microwave amplifiers, and narrow-bandwidth electrical bandpass filters (Electricalbandpass filters, EBF). In OEO, the light emitted by the laser passes through the electro-optic modulator to complete the electro-optic conver...

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Problems solved by technology

[0004] In view of the above defects or improvement needs of the prior art, in order to solve the defects of the traditional OEO scheme multi-mode oscillation and small tuning range, the present invention provides a cascade-based microwave photonic bandpass filter (Microwave photonicbandpass filter, MPBF) Broadband tunable OEO, to obtain a microwave signal source with ultra-wide range continuous tunability and single-mode oscillation

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