Heterodyne detection device based on light injection locking and light phase-locked loop

Abstract

The invention provides a heterodyne detection device based on light injection locking and a light phase-locked loop, which comprises a polarization tracking section, a heterodyne detection section anda down-conversion section, and is characterized in that the heterodyne detection section comprises an injection locking section, a coherent detection section and a light phase-locked feedback loop; the injection locking section comprises a first polarization-maintaining optical branching device, an optical phase shifter, a polarization-maintaining circulator, a local laser and a second polarization-maintaining optical branching device; the coherent detection section comprises a polarization-maintaining 2 * 2 3dB coupler, a balance light detector pair, a low-noise trans-impedance amplifier anda first power divider; the optical phase-locked feedback loop comprises a first amplifier and a loop filter; the down-conversion section comprises an ultra-narrow band-pass filter, a second amplifier, a second power divider, a phase shifter, a pi / 2 power divider, a third amplifier, a third power divider, a first mixer, a second mixer, a first low-pass filter and a second low-pass filter. Heterodyne detection is adopted, frequency synchronization of LO light waves and main control light waves is achieved, the receiver achieves zero frequency deviation, phase noise is small, and output signalsare stable.

Description

technical field [0001] The invention relates to the field of optical receivers, in particular to a heterodyne detection device based on optical injection locking and an optical phase-locked loop. Background technique [0002] The optical detection technology applied in the existing optical access network is direct detection (envelope detection). The idea of ​​optical coherent detection technology originated from the radio heterodyne detection technology. With the help of the multiplication effect of the strong power of the local oscillator, even if the external signal is very weak, a sufficiently large output signal can still be generated in the detection circuit, thereby achieving high receiver sensitivity. Utilizing the tuning of the local oscillation frequency, the user can choose to receive the information he needs among various signals and many channels. Therefore, high receiving sensitivity and strong frequency selectivity are the fundamental advantages of coherent d...

AI Technical Summary

Problems solved by technology

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is that the existing optical coherent receivers have large frequency offset, large phase noise, large power consumption, high software complexity and high system cost. The present invention uses optical injection locking to synchronize the frequency of the LO light wave and the main control light wave, and the optical receiver realizes zero frequency offset, small phase noise, and stable output signal

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