Titanium oxide coatings drastically reduce thermal effects in Lithium Niobate

Problem

Lithium niobate (LN), possessing wide transparent window, strong electro-optics effect and large second/third- order nonlinearities, is an ideal material platform for integrated photonic applications. Microring resonators are particularly suitable as integrated photonic components, given their flexibility of device engineering and their potential for large-scale integration. Unfortunately, microring resonators are susceptible to temperature fluctuation, which has become a major challenge for their implementation in a practical environment. The realization of LN microring resonators insensitive to temperature fluctuation is thus crucial for a variety of applications in communication, sensing, and nonlinear/quantum photonics. Additionally, LN suffers from serious optical damage when the optical intensity becomes significant inside the material. Photorefractive-induced optical damage has become the major challenge for the application of LN devices in the high-power regime.

 

Solution

By cladding LN microring resonators with a thin layer of titanium oxide (TiO2), we were able to greatly suppress the temperature sensitivity, while keeping the optical quality factor nearly intact. Our technology completely cancels the first-order thermo-optic effect at room temperature, leaving only slight quadratic temperature dependence of cavity resonance wavelength with a magnitude of only 30 pm for temperature range of 15 – 25°C. Additionally, the TiO2 cladding is able to completely quench the photorefractive effect, making the devices sustainable for high optical power.

 

See https://doi.org/10.1364/OE.398363

 

URV Reference Number: 2-20085
Patent Information:
For Information, Contact:
Curtis Broadbent
Licensing Manager
University of Rochester
585.273.3250
curtis.broadbent@rochester.edu
Inventors:
Qiang Lin
Jingwei Ling
Keywords: