High-precision tunable infrared reflectometer

Abstract

Articles you may be interested inComb-assisted subkilohertz linewidth quantum cascade laser for high-precision mid-infrared spectroscopy This report describes a double-bounce reflectometer operating between 1 and 4 fl m. This reflectometer uses th~ Nernst glower as a source in conjunction with a liquid N 2 -cooled InSb detector. Dat~ collec~lOn was best accomplished with a noise eliminating sample-and-hold system and a 10w-n~lse straight ac amplifier in conjunction with a computer. The reflectometer was evaluated usmg two samples with different metallic coatings, one aluminum and the other gold. Average absolute reflectance values of 95.059 ± 0.025% for the aluminum sample and 98.0~~±0.017% for the gold sample were obtained at 3.79 flm at 45· incidence angle. The precIsIOn of the reflectometer was better than 0.03% for measurements made over a period of several days.