Distortion-free amplification of 100 GHz mode-locked optical frequency comb using quantum dot technology.

Area of Science:

• Photonics
• Semiconductor Devices
• Optical Communications

Background:

• High-repetition-rate semiconductor mode-locked optical frequency comb (ML-OFC) sources are crucial for dense wavelength-division multiplexing.
• Ultrafast gain recovery in semiconductor optical amplifiers (SOAs) is essential for amplifying ultra-fast pulse trains from ML-OFCs in high-speed networks.

Purpose of the Study:

• To demonstrate ultrafast and pattern-free amplification of ~100 GHz pulsed trains from a passively ML-OFC using an SOA.
• To achieve high-speed non-return-to-zero (NRZ) data transmission up to 80 Gbaud/s.

Main Methods:

• Utilized quantum dot (QD) technology, specifically InAs/GaAs QD materials, for fabricating both the ML-OFC and SOA.
• Employed SOAs with ultrafast gain dynamics for amplification of ML-OFC pulse trains.
• Conducted 80 Gbaud/s NRZ data transmission experiments.

Main Results:

• Achieved ultrafast and pattern-free amplification of ~100 GHz pulsed trains.
• Successfully demonstrated 80 Gbaud/s NRZ data transmission.
• Both ML-OFC and SOA were fabricated from identical InAs/GaAs QD materials operating at the O-band.

Conclusions:

• Quantum dot technology offers unique properties like ultrafast gain dynamics and pattern-effect-free amplification at the O-band.
• The use of identical QD materials for ML-OFC and SOA fabrication facilitates monolithic integration for advanced photonic chips.
• This work paves the way for future integrated photonic systems combining ML-OFCs and SOAs.