Dynasil Homogeneity Data

HOMOGENEITY

Optical Homogeneity refers to the degree of refractive index can (Δn) along the optical path within a given blank. The homogeneity of an optical element is of great importance since the variations in refractive index distort the wavefront of light transmitted through the optical component..

Synthetic Fused Silica - Optical Homogeneity Table 1
Fused Silica Grade	Index homogeneity Class²				Maximum Index Variation (@ 632.8 Nanometers)
	Dynasil®			Corning HPFS® 7980¹	(X 10^-6)
	Optical Grade	UV Grade	X=	Corning HPFS® 7980¹	(X 10^-6)
Selected Fused Silica (Selected for lowest inclusions, bubbles, strain, and striae) ( See Table 2)	410X	110X
			1	A	1.0
				B	1.5
			2	C	2.0
			3	D	3.0
			4	E	4.0
			5	F	5.0
			6	-	6.0
			7	-	7.0
			0	G	Not Specified
Standard Fused Silica (For inclusions, bubbles, strain and striae specifications.) (See Table 2)	400X	100X
			1	A	1.0
				B	1.5
			2	C	2.0
			3	D	3.0
			4	E	4.0
			5	F	5.0
			6	-	6.0
			7	-	7.0
			0	G	Not Specified
Commercial Fused Silica	5000				Not Specified
Commercial Fused Silica	6000				Not Specified
¹Minimum external transmittance at 185 nanometers 18 80% for UV grades when measured through a 0.394"" (10mm) polished, uncoated sample. ²Index Homogeneity: a. Blanks 12"" in diameter (or diagonal) and under will be analyzed over the full aperture. Larger blanks will be analyzed using multiple overlaping apertures. b. The minimum thickness for index homogeneity verification is 0.750"" (19mm). Measurements are made through the optical face. c. If requested at time of order acceptance, and for a nominal fee, interferograms will be supplied.

Synthetic Fused Silica - Inclusions and Bubbles Table 2
Fused Silica Grade ^4,5	Inclusion Class³			Maximum Blank Size (Dynasil Material)	Inclusions and Bubbles
	Dynasil®		Corning HPFS® 7980³	Diameter or Diagonal X Thickness mm (inch)	Total Inclusion Cross - Section mm² / 100cm³ (Upper Limit in in² / in³)	Maximum Diameter of Largest Inclusion mm (inch)
	Optical Grade	UV Grade³	Corning HPFS® 7980³	Diameter or Diagonal X Thickness mm (inch)		Maximum Diameter of Largest Inclusion mm (inch)
Selected Fused Silica	410X	110X	0	152 X 51 (6 X 2)	0.03 (7.62 X 10^-6)	0.10 (.004)
Selected Fused Silica			1	305 X 51 (12 X 2)	0.10 (2.54 X 10^-5)	0.25 (.011)
Standard Fused Silica	400X	100X	2	203 x 51 (8 x 2)	0.25 (6.35 x 10^-5)	0.50 (.020)
			3	356 x 51 (14 x 2)	0.50 (1.27 x 10^-4)	0.76 (.030)
			4	559 x 76 (22 x 3)	1.00 (2.54 x 10^-4)	1.00 (.040)
Commercial Fused Silica	5000		5	559 x 102 (22 x 4)	2.00 (5.08 x 10^-4)	1.27 (.050)
Commercial Fused Silica	6000			559 x 102 (22 x 4)	4.00 (1.02 x 10^-3)	2.03 (.080)
³ Inclusions, bubbles and seeds smaller than 0.10mm (0.004"") in diameter are disregarded in this specification. ⁴ All Selected and Standard Grade material meets the striae requirements of ISO 10110-4 Class 2/5 (No Visiblie Striae) in the thickness direction. ⁵ All Selected and Standard Grade material meets or exceeds the stress birefringence requirements of ISO 10110-2 Class 0/5 (Optical Path difference ≤ 5 nanometers per centimeter). Other specicications available upon request.