Athermal echelle grating and tunable echelle grating demultiplexers using a Mach-Zehnder interferometer launch...

Area of Science:

• Photonics
• Integrated Optics
• Optical Communications

Background:

• Echelle grating demultiplexers are crucial for wavelength division multiplexing (WDM).
• Temperature fluctuations affect the channel wavelengths of conventional demultiplexers, impacting performance.
• Mach-Zehnder interferometers (MZIs) offer potential for wavelength control in photonic devices.

Purpose of the Study:

• To experimentally compare three silicon photonic echelle grating demultiplexers integrated with MZI launch structures.
• To investigate methods for controlling temperature-induced wavelength shifts in echelle demultiplexers.
• To evaluate the power efficiency of active wavelength tuning using MZIs.

Main Methods:

• Fabrication of silicon photonic echelle grating demultiplexers with integrated MZI launch structures.
• Experimental characterization of demultiplexer performance under varying temperature conditions.
• Implementation of athermal, super-thermal, and actively tuned MZI configurations.

Main Results:

• Athermal configuration reduced spectral shift to <10 pm/°C (vs. 83 pm/°C for unmodified devices).
• Super-thermal configuration achieved an enhanced tuning rate of 170 pm/°C.
• Active tuning using an on-chip heater corrected for 20 °C fluctuations with <20 mA drive current.

Conclusions:

• MZI integration provides versatile control over echelle demultiplexer channel wavelengths.
• Active tuning offers a low-power, efficient method for wavelength stabilization in optical systems.
• The developed devices show significant improvements in thermal stability and tunability for WDM applications.