Thermal-emission measurements near room temperature using Fourier-transform infrared spectroscopy

TL;DR

This paper investigates the challenges of accurately measuring thermal emission near room temperature using FTIR spectroscopy, highlighting the impact of background thermal emission from optical components and proposing considerations for proper calibration.

Contribution

It reveals the effect of background thermal emission in FTIR measurements near room temperature and emphasizes the need for calibration awareness.

Findings

Background thermal emission appears as a negative contribution in FTIR signals.

Proper calibration is essential for accurate near-room-temperature thermal-emission measurements.

Understanding optical component contributions improves measurement accuracy.

Abstract

Accurate characterization of thermal emitters can be challenging due to the presence of background thermal emission from components of the experimental setup and the surrounding environment. This is especially true for an emitter operating close to room temperature. Here, we explore characterization of near-room-temperature thermal emitters using Fourier-transform infrared (FTIR) spectroscopy. We find that the thermal background arising from optical components placed between the beam splitter and the detector in an FTIR spectrometer appears as a "negative" contribution to the Fourier-transformed signal, leading to errors in thermal-emission measurements near room temperature. Awareness of this contribution will help properly calibrate low-temperature thermal-emission measurements.