Thermal Control of a Dual Mode Parametric Sapphire Transducer

TL;DR

This paper introduces a method to enhance the thermal stability of a sapphire dielectric transducer by using dual-mode frequency measurements to distinguish between gap changes and temperature effects.

Contribution

It presents a novel approach combining dual-mode measurements with a simple model to control thermal effects in sapphire transducers.

Findings

Effective discrimination of gap and temperature-induced frequency shifts.

A practical procedure for measuring tuning parameters.

Improved thermal stability in sapphire dielectric transducers.

Abstract

We propose a method to control the thermal stability of a sapphire dielectric transducer made with two dielectric disks separated by a thin gap and resonating in the whispering gallery (WG) modes of the electromagnetic field. The simultaneous measurement of the frequencies of both a WGH mode and a WGE mode allows one to discriminate the frequency shifts due to gap variations from those due to temperature instability. A simple model, valid in quasi equilibrium conditions, describes the frequency shift of the two modes in terms of four tuning parameters. A procedure for the direct measurement of them is presented.