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S-LAL20 is a lower cost alternative to S-YGH51

S-LAL20 is an optical glass which has negative dn/dT. Cars are used in environments where the temperature ranges from below zero (cold district) to 50 °C or above (inside car in summer). And it's common in the optical system of Automotive camera lenses taht the focal length is fixed. Since many optical glasses have positive dn/dT, by combining these optical glasses with S-LAL20 the refractive index fluctuations due to temperature change can be modified efficiently. In addition, S-LAL20 can be used for projectors, photographic interchangeable lenses and various other applications.


  • Negative dn/dT at the region of LAL dn/dT(Dline 40℃~60℃) -1.2 2
  • The highest refractive index among glasses with negative dn / dT at the region of low dispersion nd approximately 1.7 (Until now S-PHM52 had the highest nd. The nd value is approximately 1.62)


Type Code nc nd nF ng vd s.g. Coloring
S-LAL20 699511 1.69520 1.69930 1.70888 1.71647 51.11 4.38 370/310