To reduce thermo-optic depolarization, a direct way is to make use of the thin crystal with modesta Raman spectra of DKDP crystals51 and b dependence in the variation in Raman shift in the fully symmetric PO4 vibration in DKDP about the degree of deuteration51. Images reprinted with the subsequent permission: (a)51, (b)51 within the Optical Modern