The PLZT OPTICAL SWITCH technology

EpiPhotonics pioneers and leads the design and manufacture of PLZT thin-film waveguide technology. PLZT is one of most attractive materials for the integration of high-channel count and/or various photonic functions into a small monolithic chip, with high-speed control and low-power dissipation. Its efficient, voltage-induced index change, that is, the electro-optic effect, enable thermal cross-talk free integration, miniaturization of electrodes, and low power dissipation. Moreover, its suitable high refractive index (2.45) decreases the bending radius of a classic waveguide.

PLZT optical switches have a MMI-MZ (Multi Mode Interference-Mach Zhender) type switch design with wavelenth insensitive nature. The PLZT growth and the PLZT waveguide are described below.

The solid-phase epitaxial growth technology

EpiPhotonics succeeded in producing the world's first low-loss, thin-film waveguide by using solid-phase epitaxy (SPE). SPE differs from widely used vapor-phase growth technologies, such as sputtering and MOCVD. In our process, uniquely synthesized metal organic solutions are applied to substrates and heated at ambient pressure to form amorphous films. These films are then heated to create epitaxial single-crystals. This manufacturing SPE method is extremely simple and eliminates the need for large-scale vacuum equipment, making it possible for drastic cost reduction.

Epitaxial optical waveguide technology

Buried PLZT waveguides are grown on Nb:SrTiO3 semiconductor substrates in order to facilitate application of electrical field. Using this sandwiched electrode structure and combining it with PLZT's inherently high electro-optic coefficient, we have achieved drastic improvements in switching and/or modulating performances;

• High-speed switching (<5ns)
• Low driving voltage
• Low insertion loss
• Low polarization dependence
• Low power consumption
• Miniaturization

Solid-phase epitaxial growth technology combined with our micro-fabrication technique, guarantees huge cost reduction. Exploiting the high index nature of our material and realizing a buried waveguide, low-loss sharp S-bends and efficient waveguide structure are assured. This allows us to produce very compact waveguide devices including switches, modulators, and AWGs

Intellectual property

At EpiPhotonics, we excel in creating innovative and efficient products based on our proprietary thin film PLZT waveguide technology based on design and manufacturing processes refined over decades of research and development. The devices utilizing the technology enabled us to develop high-speed integrated subsystems with performance levels that were deemed impossible a short time ago. EpiPhotonics's success and ability to compete depends on its ability to develop technological expertise internally. EpiPhotonics relies on a combination of patent and trade secret laws. EpiPhotonics' intellectual property is protected by a portfolio of more than 50 patents, including transferred patents from Keio University, in the United States and in Japan.

The patents portfolio covers precursor synthesis, thin-film growth, micro-fabrication, waveguide structure, integration on semiconductor, and device structures.

White Paper

Nano-Second Speed PLZT Waveguide Switches and Filters