I. Introduction

Chromatic confocal sensors [1], also called polychromatic confocal sensors, offer rapid noncontact distance and displacement measurements for all types of surfaces with micron and even sub-micron resolution, at moderate cost. This technique has been commercialized over a decade ago, and currently several manufacturers offer these sensors. In general, these commercial sensors are supplied factory calibrated for room temperature operation. In order to enable correct operation over a large temperature range, we discuss and quantify the temperature dependence of factors affecting the measurement.