Time domain multiplexed spatial division multiplexing receiver.

Area of Science:

• Optical communications
• Signal processing
• Fiber optics

Background:

• Spatial division multiplexing (SDM) and time domain multiplexing (TDM) are key technologies for increasing fiber optic communication capacity.
• Current SDM systems often require multiple complex coherent receivers for each spatial mode.
• Efficiently receiving multiple modes with reduced hardware is a significant challenge in optical networks.

Purpose of the Study:

• To demonstrate a novel TDM-SDM receiver capable of receiving multiple dual-polarization modes with a single coherent receiver.
• To experimentally validate the performance of this integrated receiver system.
• To compare the performance of the TDM-SDM receiver against existing multi-receiver setups.

Main Methods:

• Experimental demonstration of a novel TDM-SDM receiver architecture.
• Utilizing a single coherent receiver and a 4-port oscilloscope for multi-mode reception.
• Transmission of 28GBaud QPSK, 8, 16, and 32QAM signals over 41.7km of few-mode fiber.
• Employing carrier phase estimation with digital phase-locked loops for frequency offset compensation.

Main Results:

• Successful reception of >1 dual-polarization mode using a single coherent receiver and 4-port oscilloscope.
• Demonstration of 3-mode transmission with various modulation formats (QPSK to 32QAM) over few-mode fiber.
• Performance comparable to systems using three dedicated coherent receivers for each mode.
• Effective frequency offset compensation using digital phase-locked loops.

Conclusions:

• The novel TDM-SDM receiver offers a simplified and efficient solution for multi-mode optical signal reception.
• This technology reduces hardware complexity and potentially lowers costs in high-capacity optical networks.
• The demonstrated performance indicates its viability for future high-speed, high-capacity fiber optic communication systems.