MONOLITHIC SAPPHIRE – RUTILE TEMPERATURE COMPENSATED WHISPERING GALLERY MODE RESONATOR OSCILLATOR AT 47K

摘要

A 2μm thick film of Rutile (TiO_2) was deposited on a sapphire disk using a sol-gel method to realize a temperature compensated microwave resonator operating in whispering gallery mode configuration. Our resonator though not yet completely optimized shows turnover temperatures ranging from 40 to 60K depending on the mode azimutal number. For the WGH_(7,0,0) mode at 9.4 GHz, the Q-factor is of the order of 1.5×10~6 at 45.7K. This resonator, stabilized near its turnover temperature, has been introduced in an oscillator loop. Preliminary measurements demonstrate frequency stability better than 2.10~(-12) for 1 < τ < 10 s.