Reconfigurable symmetric pulses generation using on-chip cascaded optical differentiators

Area of Science:

• Photonics
• Optical Engineering
• Signal Processing

Background:

• Optical pulse shaping is crucial for various applications, including telecommunications and optical computing.
• Existing methods may lack programmability or require complex setups.

Purpose of the Study:

• To develop a programmable method for generating diverse optical pulse shapes.
• To demonstrate the generation of specific pulse shapes like flat-top, parabolic, and triangular pulses.
• To investigate the impact of cascaded differentiators on pulse shaping accuracy and tunability.

Main Methods:

• Utilizing cascaded frequency-detuned optical differentiators.
• Adjusting the central wavelength of each differentiator to control pulse output.
• Employing thermally tunable delay interferometers on a silicon-on-insulator (SOI) platform.

Main Results:

• Successfully generated flat-top, parabolic, and triangular pulses from a 20-ps Gaussian-like pulse.
• Demonstrated tunable pulse widths using up to three cascaded differentiators.
• Observed improved synthesized accuracy and wider tuning range with more cascaded stages.
• Fabricated a compact (943μm × 395μm) and stable optical pulse shaping system.

Conclusions:

• The proposed method offers a programmable and versatile approach to optical pulse shaping.
• The SOI-based implementation enables compact and stable pulse shaping systems.
• This technique has potential for applications requiring precise control over optical pulse characteristics.