Fig. 1. Beam-splitting process^[25]. (a) Beam incident from the colored facet of crystal; (b)(c) illustrate the beam-splitting process induced by colored facets

Fig. 2. The backscatter coordinate system^[38]

Fig. 3. The process of a light beam through an ice crystal^[38]

Fig. 4. The process of a beam slicing through an ice crystal

Fig. 5. The last beam of light out of the ice crystal

Fig. 6. Illustration of particle scattering

Fig. 7. Schematic diagram of the hollow ice crystal model^[33]

Fig. 8. Backscattering cross section (a), depolarization ratio (b), and lidar ratio (c) of randomly oriented hollow and solid ice crystals

Fig. 9. Color ratio of randomly oriented hollow and solid ice crystals. (a) Color ratio at 1064 nm and 532 nm wavelengths;(b) color ratio at 532 nm and 355 nm wavelengths