Optimized high-speed all-optical 2-bit ADCbased on two-dimensional photonic crystal nanoresonators

Area of Science:

• Photonics
• Nanotechnology
• Integrated Optics

Background:

• Analog-to-digital converters (ADCs) are crucial components in optical signal processing.
• Existing optical ADC designs often face limitations in speed, size, or power efficiency.
• Photonic crystals (PCs) offer unique properties for developing advanced optical devices.

Purpose of the Study:

• To design and simulate a novel 2-bit optical analog-to-digital converter (ADC).
• To achieve a faster and more compact ADC structure using 2D photonic crystal (PC) technology.
• To optimize the PC structure for maximum output optical power and efficiency.

Main Methods:

• Utilized a 2D photonic crystal (PC) structure with a square lattice of silicon rods in an air background.
• Integrated optical filters, linear waveguides, nanoresonators, and interference effects for ADC functionality.
• Employed the plane wave expansion method for photonic bandgap analysis and the finite-difference time-domain (FDTD) method for spectral analysis.

Main Results:

• Achieved a response time of approximately 1.63 ps and a sampling rate of 613 GS/s.
• The designed structure has a compact size of ~194µm².
• Demonstrated significantly lower power consumption (mW/µm²) compared to similar devices, utilizing nonlinear effects.

Conclusions:

• The proposed 2D PC-based 2-bit ADC offers superior performance in terms of speed, size, and power efficiency.
• The design exhibits simplicity and flexibility, adaptable for higher-bit converters.
• This high-performance optical ADC is recommended for integration into optical integrated circuits.