Monolithically integrated dual-quadrature receiver on InP with 30 nm tunable local oscillator

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Optical Communications

Background:

• Coherent receivers are crucial for high-speed optical data transmission.
• Integration of receiver components reduces size and cost while improving performance.
• Widely-tunable local oscillators are essential for flexible wavelength selection in optical networks.

Purpose of the Study:

• To demonstrate a monolithically integrated dual-quadrature coherent receiver.
• To showcase the performance of a widely-tunable SG-DBR local oscillator within the integrated receiver.
• To evaluate the receiver's performance at various wavelengths using high-speed data transmission.

Main Methods:

• Monolithic integration of a tunable semiconductor source-grating distributed Bragg reflector (SG-DBR) local oscillator, signal input semiconductor optical amplifiers (SOAs), a 90° optical hybrid, and four photodetectors.
• Utilizing 20 Gb/s non-return-to-zero quaternary phase-shift keying (NRZ-QPSK) modulation format.
• Testing the receiver's performance across four different wavelengths.

Main Results:

• Successful monolithic integration of all receiver components.
• Demonstration of a widely-tunable SG-DBR local oscillator with over 30 nm tuning range.
• Achieved a required OSNR of 10 dB for a bit error rate (BER) of 10⁻³ at 20 Gb/s NRZ-QPSK across multiple wavelengths.

Conclusions:

• The integrated coherent receiver offers a compact and efficient solution for high-speed optical communication systems.
• The demonstrated device enables flexible and reliable data transmission over a wide range of wavelengths.
• This technology has the potential to advance optical network capabilities.