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New Glass Types


Anomalous dispersion glasses with both low refractive index and low dispersion have ideal characteristics for the correction of chromatic aberration, however, they typically have a negative change in refractive index with changes in temperature (-dn/dT). S-FPM3 overcomes this issue and keeps the anomalous dispersion on the positive side while bringing the temperature coefficient close to 0

Eco Optical Glass
Refractive Index nd 1.53775 1.59522
Abbe Number νd 74.70 67.74
-30~70°C 115 117
+100~300°C 138 135
Transformation Point Tg(°C) 496 571
Yield Point At(°C) 524 596
Coloring λ80 345 355
λ5 - 295
Chemical ResistanceRW(P) 1 1
RA(P) 4 2
W(S) 4 2
SR 5.1 51.3
PR 4.1 4.1
Specific Gravity 3.64 4.17
Knoop Hardness Hk 390[4] 390[4]
Abrasion Aa 373 488
Detail Catalog DATA PDF PDF
Available shapes

•saw cut center-less
groundcylindrical blanks
•polished ball
•cut blanks
•polished preform

•saw cut center-less
groundcylindrical blanks
•polished ball
•cut blanks

Please consult us about available size and tolerance.

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