Highly linear ring modulator from hybrid silicon and lithium niobate

Area of Science:

• Photonics
• Materials Science
• Electrical Engineering

Background:

• Analog optical links require highly linear modulators.
• Existing silicon modulators face linearity limitations due to plasma dispersion.
• Lithium niobate (LiNbO3) is a promising material for electro-optic modulation.

Purpose of the Study:

• To demonstrate a highly linear ring modulator by integrating lithium niobate with silicon.
• To evaluate the linearity performance of the proposed device for analog optical communication.

Main Methods:

• Bonding of ion-sliced x-cut lithium niobate onto a silicon ring resonator.
• Fabrication of a compact ring modulator.
• Measurement of third-order intermodulation distortion (IMD3) spurious free dynamic range (SFDR).

Main Results:

• Achieved a SFDR of 98.1 dB·Hz^(2/3) at 1 GHz and 87.6 dB·Hz^(2/3) at 10 GHz.
• Demonstrated linearity comparable to a lithium niobate Mach-Zehnder interferometer modulator.
• Exhibited linearity over an order of magnitude greater than silicon ring modulators relying on plasma dispersion.

Conclusions:

• The proposed lithium niobate on silicon ring modulator offers superior linearity for analog optical links.
• This integration platform enables compact and high-performance modulators.
• Exploiting the second-order susceptibility of lithium niobate on silicon is a viable path for advanced optical modulators.