Fig. 1. (a) As-grown TTG-CVD-ZnS bulk and (b) device after coating

Fig. 2. XRD patterns of annealed TTG-CVD-ZnS bulk

Fig. 3. Surface topography of TTG-CVD-ZnS tested by SEM and traditional CVD-ZnS

Fig. 4. Infrared transmittance of CVD-ZnS

Fig. 5. Infrared optical system layout of K1509 IR lens

Fig. 6. MTF of TTG-CVD-ZnS based infrared optical lens

Fig. 7. Aberration raised (a) dispersion spot (unit: mm) and (b) distortion in infrared optical lens

Fig. 8. (a) TTG-CVD-ZnS based infrared imaging system module; (b) Infrared imaging for different scenes