1：Experimental Design and Method Selection:

The study involved growing Tm3+-doped KCl single crystals using the Bridgman–Stockbarger technique and characterizing them through various spectroscopic and analytical methods to investigate optical and luminescence properties.

2：Sample Selection and Data Sources:

Single crystals of thulium-doped KCl (

3：99% purity) were grown with 3% by weight thulium concentration. Samples of size approximately 5 × 5 × 1 mm3 were used for all studies except PL. List of Experimental Equipment and Materials:

Equipment included PerkinElmer Lambda 35 UV–Vis spectrophotometer, PerkinElmer LS 55 Luminescence spectrometer, PC-based TL analyzer (Hitachi), 60Co γ-ray source, Rigaku X-ray diffractometer, SEM-JEOL-JSM5610LV, Reinshaw Invia spectrometer, and EPR spectrometer. Materials included KCl (

4：99% purity) and thulium fluoride (Aldrich, 99% purity). Experimental Procedures and Operational Workflow:

Crystals were annealed at 400°C for half an hour and quenched to room temperature before experiments. Absorption spectra were recorded from 190–1100 nm, PL spectra from 200–900 nm at room temperature, TL glows at a heating rate of 5°C/s after γ-ray irradiation, TL emission with excitation slit closed, XRD with CuKα radiation, SEM for microstructure, laser Raman spectroscopy with λL = 700 nm, and EPR at X-band frequencies (9–10 GHz).

5：Data Analysis Methods:

Data analysis included using Chen’s peak shape method for TL trap parameters, Scherrer equation for crystallite size from XRD, and Lande formula for g-factor from EPR.