Ultra-compact silicon mode-order converters based on dielectric slots

Area of Science:

• Photonics
• Integrated Optics
• Materials Science

Background:

• Mode-order converters are crucial components in photonic integrated circuits for manipulating optical signals.
• Existing converters often suffer from large footprints and high insertion losses, limiting their practical application.

Purpose of the Study:

• To demonstrate ultra-compact mode-order converters utilizing dielectric slots on a silicon-on-insulator (SOI) platform.
• To achieve efficient conversion between different transverse electric (TE) modes with minimal signal loss.

Main Methods:

• Fabrication of mode converters on an SOI platform featuring precisely engineered dielectric slots.
• Characterization of device performance, including insertion loss and operational bandwidth, across a specific wavelength range (1520-1570 nm).
• Optimization of the converter structure to minimize footprint and insertion loss for TE0 to TE1 and TE0 to TE2 mode conversion.

Main Results:

• Demonstration of an ultra-compact TE0 to TE1 mode converter with a footprint of 0.8×1.2 µm² and insertion loss < 1.2 dB.
• Optimized converters achieved insertion losses < 0.5 dB for TE0 to TE1 and TE0 to TE2 modes, with footprints of 0.88×2.3 µm² and 1.4×2.4 µm², respectively.
• The proposed devices exhibit cascadability and scalability for higher-order mode conversion.

Conclusions:

• Ultra-compact and low-loss mode-order converters are achievable using dielectric slot structures on SOI.
• The demonstrated devices offer significant advantages in terms of size and performance for integrated photonic applications.
• The scalability and cascadability of these converters pave the way for complex photonic systems and advanced signal processing.