Power insensitive surface-normal electroabsorption modulators.

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Surface-normal electroabsorption modulators (SNEAMs) offer unique electro-optic modulation capabilities.
• High optical power operation of SNEAMs is limited by thermal nonlinearities within the active volume.
• Existing methods to mitigate thermal effects often require complex and power-intensive control systems.

Purpose of the Study:

• To introduce a novel, passive approach for enhancing SNEAM insensitivity to optical power.
• To overcome the limitations imposed by thermal nonlinearities in SNEAMs without active feedback or heating.
• To demonstrate improved performance and stability of SNEAMs under high optical power conditions.

Main Methods:

• Passive compensation of the thermo-optic dependence within the SNEAM resonant cavity.
• Experimental characterization of SNEAM wavelength shift under varying optical power.
• High-speed eye diagram analysis to assess signal integrity at increased input power levels.

Main Results:

• Achieved an eight-fold reduction in the SNEAM response wavelength shift at 4 dBm input power.
• Demonstrated no significant degradation in the SNEAM eye diagram at 25 Gbit/s with input power increased to 2 dBm.
• The achieved input power tolerance is approximately four times higher than that of conventional SNEAMs.

Conclusions:

• The proposed passive compensation method effectively renders SNEAMs insensitive to optical power variations.
• This approach offers a power-efficient and simpler solution for high-power SNEAM applications.
• The results pave the way for more robust and high-performance electro-optic modulators in demanding optical systems.