S-LAL20 is an optical glass which has negative dn/dt. Cars are used in environments where the temperature change is large from below zero (cold district) to 50 °C or above (inside car in summer). In the optical system of Automotive camera lenses, it's common that the focal length is fixed. Since many optical glasses have positive dn/dt, by combining these optical glasses with S-LAL20, it is expected that refractive index fluctuations due to temperature change can be modified efficiently. In addition, S-LAL20 can be used for not only Automotive camera lenses but also projectors, photographic interchangeable lenses and various applications.
(Advantages)
1.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)
S-LAL20
