Dynasil Homogeneity Table

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.

TABLE 1

Synthetic Fused Silica-Optical Homogeneity

FUSED SILICA GRADE

Index Homogeneity Class²

Maximum Index Variation @ 632.8 nanometers

DYNASIL

CORNING

HPFS^®

7980¹

(X 10º)

Optical

Grade

Selected Fused Silica

Selected for lowest inclusions, bubbles, strain and striae.

(see Table 2)

410X

110X

1.0

1.5

2.0

3.0

4.0

5.0

6.0

7.0

Not Specified

Standard Fused Silica

(see Table 2 specifications on inclusions, bubbles, strain and striae)

410X

110X

1.0

1.5

2.0

3.0

4.0

5.0

6.0

7.0

Not Specified

Commercial Fused Silica

5000

Not Specified

6000

Not Specified

¹Minimum external transmittance at 185 nm is 80% for UV grades when measured through a .391” (10mm) polished uncoated sample.

² A. Blanks 12” in diameter (or diagonal) and under will be analyzed over the full aperture. Large blanks will be analyzed using multiple overlapping apertures.

B. The maximum thickness for index homogeneity verification is .75” (19mm). Measurements are made through the optical face.

C. If requested at time of order and for a nominal fee, interferograms will be supplied.

TABLE 2 Synthetic Fused Silica – Inclusions and Bubbles
Fused Silica Grade ^4.5	Inclusion Class³			Max. Blank Dynasil Mat.	Inclusions & Bubbles
Fused Silica Grade ^4.5	Dynasil Optical	Dynasil UV	Corning HPFS^® 7980³	Diameter Or Diagonal X Thickness mm(in)	Tot. Inclusion Cross-Section Mm²/100cm³ Upper Limit in in^2/in²	Maximum Diameter of Largest Inclusion mm(in)
Selected	410X	110X	0	152x51(6 x 2)	.03(7.62 x10⁴)	.10(.004)
Selected			1	305 x 51(12x2)	.10(2.54x10⁴)	.25(.011)
Standard
	400X	100X	2	203x 51(8 x 2)	.25(6.35x10⁴)	.50(.020)
			3	356 x 51(14 x 2)	.50(1.27x10⁴)	.76(.030)
			4	559 x 76(22x3)	1.00(2.54x10⁴)	1.00(.040)
Commercial
	5000		5	559 x 102(22x4)	2.00(5.08x10⁴)	1.27(.050)
	6000			559 x 102(22x4)	4.00(1.02x10⁴)	2.03(.080)
³Inclusions, bubbles and seeds smaller than .10mm (.004”) in diameter are disregarded in this specification. ⁴All Selected and Standard materials meets the striae requirements of ISO 10110-4 Class 2/5 (No Visible Striae) in the thickness directions. ⁵All Selected and Standard Grade material meets or exceeds the stress birefringence requirements ISO 10110-2 Class 0/5 (Optical Path Difference ≤ nm per cm) Other specifications available upon request.