Bias-free electro-optic polymer-based two-section Y-branch waveguide modulator with 22 dB linearity enhancement

Area of Science:

• Photonics
• Materials Science
• Electrical Engineering

Background:

• Nonlinear optical effects in materials are crucial for modulator performance.
• Achieving high linearity and distortion suppression in modulators is a key challenge.
• Domain-inverted modulation offers a potential pathway to improved device characteristics.

Purpose of the Study:

• To fabricate and test a bias-free, two-section Y-branch directional coupler modulator.
• To evaluate the modulator's linearity and distortion suppression capabilities.
• To compare the device performance against conventional Mach-Zehnder modulators.

Main Methods:

• Fabrication of a Y-branch directional coupler modulator using 25 wt.% AJLS102/APC as the active core layer.
• Experimental confirmation of the material's r(33) nonlinear coefficient (56 pm/V at 1.59 microm).
• Performance testing including extinction voltage measurement and two-tone analysis.

Main Results:

• The fabricated modulator demonstrated an extinction voltage of 4 V.
• A distortion suppression of 64 dB was achieved at 25% modulation depth.
• This represents a 22 dB improvement compared to conventional Mach-Zehnder modulators.

Conclusions:

• The developed Y-branch directional coupler modulator exhibits high linearity and excellent distortion suppression.
• Domain-inverted modulation is an effective technique for enhancing modulator performance.
• The device shows significant potential for advanced optical communication systems.