Azocarbazole Polymethacrylates as Single-Component Electrooptic Materials

Area of Science:

• Materials Science
• Polymer Chemistry
• Optoelectronics

Background:

• Azobenzene and carbazole-containing polymers offer multifunctional properties.
• Electrooptic activity and photoconductivity are key for advanced optical applications.

Purpose of the Study:

• To synthesize and characterize amorphous polymers integrating electrooptic and photoconductive functionalities.
• To investigate the impact of chromophore mobility on photoinduced birefringence and photorefractive properties.
• To evaluate the potential of these polymers for optical data storage and processing.

Main Methods:

• Synthesis of amorphous azobenzene and carbazole-containing polymers with varying methylene spacer lengths.
• Fabrication of thin films for optical measurements.
• Photoinduced birefringence measurements using polarized light.
• Photorefractive diffraction grating inscription under an electric field.
• Two-beam optical coupling gain measurements.

Main Results:

• Polymers demonstrated reversible photoinduced birefringence and photorefractive grating inscription.
• Photoinduced orientational order, photoconductivity, and photorefractive gain decreased with increasing spacer length.
• A birefringence of 0.065 was achieved in high glass transition temperature polymers with a fast time constant (<0.8 s).
• A two-beam optical gain of 0.024 µm⁻¹ was observed, though surpassed by absorption losses.

Conclusions:

• The synthesized polymers are suitable for photoinducing birefringence and creating photorefractive gratings.
• Chromophore mobility, controlled by spacer length, significantly influences optical performance.
• These multifunctional polymers show promise for optoelectronic applications, with further optimization needed to overcome absorption losses.