Temperature-stable and high Q-factor TiO2 Bragg reflector resonator
Abstract
The highest Q-factor resonators employ whispering gallery modes in single-crystal sapphire but have poor temperature stability. Rutile was the first dielectric material used to construct a microwave dielectric resonator. However, its very high temperature coefficient of permittivity made it unsuitable for practical applications. This paper reports a high Q-factor (50 000) and temperature-stable spherical Bragg reflector resonator based on polycrystalline rutile operating at 29.9 GHz. Temperature stability is achieved by adjusting the electric filling factor of a spherical shell so that in combination with its highly negative temperature coefficient of permittivity, the effect of thermal expansion is exactly cancelled out.
- Publication:
-
Applied Physics Letters
- Pub Date:
- February 2009
- DOI:
- 10.1063/1.3086877
- Bibcode:
- 2009ApPhL..94h2906B
- Keywords:
-
- 42.79.-e;
- 85.50.-n;
- 77.22.Ch;
- Optical elements devices and systems;
- Dielectric ferroelectric and piezoelectric devices;
- Permittivity