Nd3+-doped fluoroborontellurite glass as a near-infrared optical thermometer

•This work brings valuable achievements to photonics technologies at near infrared.•It was demonstrated an optical thermometry approach of a Nd3+-doped matrix glass.•The fluoroborontellurite glass system was presented as a primary optical thermometer.•It was studied the emission of the (4F5/2, 4F3/2) → 4I9/2 transitions from 280 to 480K.•The optical thermometer has a relative sensitivity of 1.58 %K−1 at room temperature.