High-speed, rate-scalable photonic-assisted digitizer equalization by frequency comb referencing.

Area of Science:

• Electrical Engineering
• Optoelectronics
• Signal Processing

Background:

• Conventional analog-to-digital converters (ADCs) face limitations in speed and bandwidth.
• Optical domain techniques offer potential for overcoming these limitations.
• Scalability and practical implementation of high-speed optical ADCs remain challenges.

Purpose of the Study:

• To introduce a scalable analog-to-digital converter architecture.
• To leverage polychromatic sampling and optical-domain frequency referencing for enhanced performance.
• To demonstrate a practical implementation of a high-speed optical ADC.

Main Methods:

• Utilizing low-distortion replication of optical signals into spectrally distinct copies.
• Employing polychromatic parametric sampling for signal digitization.
• Implementing frequency comb referencing for distortion conversion and equalization.

Main Results:

• Demonstrated operation at 30 GS/s sampling rate.
• Achieved 6.5 effective number of bits (ENOB) in the first Nyquist zone.
• Exhibited preprocessor sampling bandwidth extending beyond 40 GHz into the second and third Nyquist zones.

Conclusions:

• The proposed architecture offers a scalable solution for high-speed analog-to-digital conversion.
• Optical-domain techniques, specifically polychromatic sampling and frequency comb referencing, enable performance beyond conventional ADC limitations.
• The demonstrated digitizer shows promise for applications requiring ultra-high bandwidth and sampling rates.