One-chip integration of optical correlator based on slow-light devices

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Conventional optical correlators often rely on bulky free-space optics, limiting miniaturization and integration.
• Photonic crystal waveguides offer unique light manipulation properties for compact optical devices.

Purpose of the Study:

• To propose and demonstrate a novel on-chip optical correlator.
• To integrate photonic crystal slow-light waveguides for optical delay scanning and photodetection.
• To achieve a significantly smaller footprint compared to traditional optical correlators.

Main Methods:

• Fabrication of an on-chip optical correlator using a CMOS-compatible process.
• Integration of two types of photonic crystal slow-light waveguides.
• Utilizing one waveguide as an optical delay scanner and the other as a two-photon-absorption photodetector.
• Experimental observation and waveform analysis of optical pulses.

Main Results:

• Demonstration of a functional on-chip optical correlator with a footprint of 1.0 × 0.3 mm(2).
• Successful observation of optical pulses with pulse widths of 5-7 picoseconds.
• Confirmation of waveform correspondence with a commercial optical correlator.
• Achieved substantial size reduction compared to free-space optical correlators.

Conclusions:

• The developed on-chip optical correlator is significantly smaller than conventional devices.
• The device accurately measures optical pulse waveforms in the picosecond range.
• This technology enables the 'one-chipping' of optical correlators and related measurement instruments, advancing integrated photonics.