Few-mode pre-amplification coherent receiving system and method for free space optical signal

• Main Authors: RAO CHENJIE, CUI SHENG, GONG LINJIE
• Format: Patent
• Language: Chinese; English
• Published: 20.08.2019
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION

The invention discloses a few-mode pre-amplification coherent receiving system and method for a free space optical signal. The system comprises a coupling lens, a few-mode optical fiber, a few-mode erbium-doped optical fiber amplifier, an optical band-pass filter, a local oscillator laser, a spatial optical coupler, a multi-mode optical detector, an analog-to-digital converter and a digital signalprocessing system. An incident light signal is coupled into the few-mode optical fiber through the coupling lens and is input into the few-mode erbium-doped optical fiber amplifier. A few-mode optical signal generated after amplification is filtered by an optical band-pass filter and then combined with local oscillation light through a spatial optical coupler to form a pseudo single sideband signal. And finally, after analog-to-digital conversion of the analog-to-digital converter and processing of the digital signal processing system, an input signal light field is reconstructed, and the influence of inter-mode disp