Network-embedded self-tuning cavity for WDM-PON transmitter

Area of Science:

• Optoelectronics
• Optical Communications
• Fiber Optics

Background:

• Wavelength Division Multiplexing Passive Optical Networks (WDM-PONs) are crucial for high-bandwidth fiber optic communication.
• Existing WDM-PON architectures often require external light sources, increasing system complexity and cost.
• Developing source-less WDM-PONs is essential for efficient and cost-effective network deployment.

Purpose of the Study:

• To demonstrate a network-embedded self-tuning cavity for source-less WDM-PON transmission.
• To evaluate the bit error rate (BER) performance of this novel cavity.
• To analyze the impact of simultaneous operation of multiple optical network units (ONUs) and downstream signal presence.

Main Methods:

• Implementation of a source-less topology utilizing a reflective element at the remote node and a reflective semiconductor optical amplifier (RSOA) at the ONU.
• Experimental setup for WDM-PON transmission over distribution fibers.
• Bit error rate (BER) testing at 1.25 Gb/s for cavities up to 5-km.
• Evaluation of polarization dependent gain (PDG) of low PDG RSOAs with 25-km and 50-km standard single mode fiber (SSMF) transmission.

Main Results:

• Successful demonstration of a network-embedded self-tuning cavity for WDM-PON.
• Achieved reliable transmission over 32 channels with up to 5-km cavity length.
• Characterized BER performance with two ONUs operating simultaneously and in the presence of downstream signals.
• Quantified polarization dependences using low PDG RSOAs over extended fiber lengths (25-km and 50-km SSMF).

Conclusions:

• The network-embedded self-tuning cavity offers a viable source-less solution for WDM-PON.
• The system demonstrates robust performance under multi-user and co-existing signal conditions.
• Low PDG RSOAs are suitable for maintaining signal integrity in longer-reach WDM-PON systems.