Photonic digital-to-analog conversion using a blue frequency chirp in a semiconductor optical amplifier

Area of Science:

• Photonics
• Optical Communications
• Signal Processing

Background:

• Photonic digital-to-analog converters (DACs) are crucial for high-speed signal processing.
• Existing photonic DACs face challenges in achieving high resolution and speed.
• Semiconductor optical amplifiers (SOAs) offer potential for novel photonic device applications.

Purpose of the Study:

• To present a novel photonic digital-to-analog conversion (DAC) technique.
• To demonstrate a 10 Gb/s, 2-bit photonic DAC using blue-chirp spectral slicing.
• To evaluate the resolution performance of the proposed photonic DAC.

Main Methods:

• Utilizing a semiconductor optical amplifier (SOA) to induce a blue-chirp spectral shift in probe signals.
• Employing spectral slicing with rectangular filters to extract logic-level-dependent probe signals.
• Experimentally demonstrating the DAC with a 10 Gb/s digital input signal and various data patterns.

Main Results:

• Successfully demonstrated a 10 Gb/s, 2-bit photonic DAC.
• Converted a 10 Gb/s digital signal to a four-level amplitude analog signal.
• Evaluated resolution using differential nonlinearity (DNL), integral nonlinearity (INL), and effective number of bits (ENOB).

Conclusions:

• The blue-chirp spectral slicing technique in SOAs is a viable method for photonic DACs.
• The demonstrated photonic DAC achieves high-speed conversion with potential for high resolution.
• This technique offers a promising approach for future optical signal processing applications.