Fast thermo-optical modulators with doped-silicon heaters operating at 2 μm

Area of Science:

• Integrated photonics
• Optical communication devices
• Semiconductor device physics

Background:

• The 2-μm-waveband is a promising window for next-generation optical communication, demanding efficient modulators.
• Existing thermo-optic (TO) modulators at 2-μm suffer from slow response and high power consumption.
• On-chip photonic systems require high-performance TO modulators and switches for reduced energy use and faster reconfiguration.

Purpose of the Study:

• To demonstrate high-performance thermo-optical Mach-Zehnder interferometer (MZI) and ring resonator modulators operating at the 2-μm-waveband.
• To overcome the limitations of slow response time and high power consumption in previous 2-μm TO devices.
• To achieve record modulation efficiency and low power consumption for integrated photonic circuits.

Main Methods:

• Fabrication of MZI and ring resonator modulators incorporating a doped silicon (p₊₊-p-p₊₊) junction within the waveguide.
• Characterization of modulation efficiency, response time, and power consumption of the developed TO devices.
• Comparison of device performance against existing 2-μm TO modulators.

Main Results:

• Achieved a record modulation efficiency of 0.17 nm/mW for the MZI modulator.
• Demonstrated the fastest response time for 2-μm TO devices, with rise/fall times of 3.49 μs/3.46 μs.
• Obtained the lowest reported Pπ power of 3.33 mW for a ring resonator-based modulator at 2-μm.

Conclusions:

• The developed p₊₊-p-p₊₊ junction-based TO modulators represent a significant advancement for 2-μm optical communication.
• These devices offer superior performance in terms of speed and energy efficiency compared to prior 2-μm TO technologies.
• The findings pave the way for more efficient and faster on-chip photonic systems operating in the 2-μm-waveband.