Integrated silicon photonic wavelength-selective switch using wavefront control waveguides.

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Silicon Photonics

Background:

• Wavelength Selective Switches (WSS) are crucial for Reconfigurable Optical Add-Drop Multiplexers (ROADM).
• Conventional WSS designs can suffer from high loss and inter-channel loss variations due to waveguide crossings.

Purpose of the Study:

• To propose and demonstrate a wavefront control type WSS utilizing silicon photonics technology.
• To overcome limitations of conventional WSS designs by eliminating waveguide crossings.

Main Methods:

• Design and fabrication of a 1x2 WSS with 16 channels (200 GHz spacing) on a 5 mm x 10 mm silicon chip.
• Implementation of arrayed waveguide gratings, a shared slab waveguide, wavefront control waveguides, and distributed Bragg reflectors.
• Switching mechanism based on phase shifting in control waveguides and directional control in the shared slab waveguide.

Main Results:

• Successful demonstration of switching operation by controlling light propagation direction.
• Achieved low loss and minimal inter-channel loss variation due to the absence of crossing waveguides.
• Reported average extinction ratios of 9.8 dB and 10.2 dB for Output#1 and Output#2, respectively, with a heater power of 183 mW per channel.

Conclusions:

• The proposed wavefront control WSS offers a promising alternative for ROADMs with improved performance.
• Silicon photonics enables compact and efficient WSS fabrication.
• The design exhibits scalability and potential for advanced optical network applications.