Dual slot-mode NOEM phase shifter.

Area of Science:

• Integrated photonics
• Silicon photonics
• Nano-opto-electro-mechanical systems (NOEMS)

Background:

• Increasing component counts in photonic systems, especially CMOS-compatible silicon photonics, present challenges in device cascading due to area, power, and response time constraints.
• Existing thermo-optic and plasma dispersion effects in silicon photonics partially address these criteria but have limitations.
• Nano-opto-electro-mechanical (NOEM) phase shifters offer potential but face challenges in achieving low voltage operation and low insertion loss.

Purpose of the Study:

• To introduce a novel NOEM phase shifter compatible with CMOS fabrication processes.
• To demonstrate a NOEM phase shifter operating at CMOS-compatible voltages (≤ 1.2 V) with low insertion loss.
• To address the limitations of current active photonic devices in cascaded implementations.

Main Methods:

• Fabrication of a novel NOEM phase shifter integrated alongside 90 nm transistors using back-end-of-line etch processing.
• Characterization of the phase shifter's performance, including phase shift, operating voltage, actuation length, insertion loss, and bandwidth.

Main Results:

• The novel NOEM phase shifter achieves a 5.63 radians phase shift at a bias of 1.08 volts.
• The device operates over an actuation length of 25 μm with an insertion loss below 0.04 dB.
• A 3 dB bandwidth of 0.26 MHz was measured for the phase shifter.

Conclusions:

• The developed NOEM phase shifter successfully operates at CMOS-compatible voltages with low insertion loss.
• This technology offers a promising solution for implementing large numbers of cascaded active photonic devices in silicon photonics.
• The integration with standard CMOS transistors simplifies fabrication and enhances applicability.