1x2 Multimode interference couplers based on semiconductor hollow waveguides formed from omnidirectional reflectors.

Area of Science:

• Photonics and Optical Engineering
• Semiconductor Devices
• Waveguide Technology

Background:

• Multimode interference (MMI) couplers are essential components in integrated optics.
• Conventional silicon-on-insulator (SOI) MMI couplers face limitations in coupling length and fabrication complexity.
• Hollow waveguide structures offer unique properties for light manipulation.

Purpose of the Study:

• To demonstrate a novel 1x2 hollow multimode interference (MMI) coupler.
• To investigate the performance of MMI couplers based on semiconductor hollow waveguides formed from omnidirectional reflectors (SHOW-ODR).
• To compare the device's performance against conventional SOI MMI couplers.

Main Methods:

• Fabrication of a 1x2 MMI coupler using SHOW-ODR technology.
• Characterization of the coupler's performance, including coupling length and uniformity.
• Wavelength-dependent measurements between 1520 and 1562 nm.
• Assessment of polarization dependence for TE and TM modes.

Main Results:

• The demonstrated SHOW-ODR MMI coupler exhibits a significantly shorter coupling length compared to conventional SOI MMI couplers.
• Achieved a 2 dB uniformity across a broad operating wavelength range (1520-1562 nm).
• The device shows weak polarization dependence for both transverse electric (TE) and transverse magnetic (TM) modes.

Conclusions:

• SHOW-ODR technology provides a promising platform for developing compact and efficient MMI couplers.
• The demonstrated device offers advantages in coupling length and uniformity for optical networking.
• The weak polarization dependence makes it suitable for various integrated photonic applications.