Patent · US Active

Method for making low-stress large-volume crystals with reduced stress birefringence and more uniform refractive index and crystals made thereby

US7968074B2 · kind B2 · utility

0Cited by

5References

22Claims

0Family size

Assignee

Hellma Materials GmbH & Co. KG · DE

Inventors

Lutz Parthier · Kleinmachnow, DE
Joerg Staeblein · Jena, DE
Gunther Wehrhan · Jena, DE
Christian Kusch · Jena, DE

Key dates

Filing date	Feb 22, 2005
Grant date	Jun 28, 2011
Priority date	—
Expiry date	Jan 20, 2028

Classification

Technology area (CPC G)Physics
CPC primaryG02B5/3083
WIPO fieldOptics
WIPO sectorInstruments

Abstract

The method produces low-stress, large-volume crystals with low birefringence and uniform index of refraction. The method includes growing the crystal with larger than desired dimensions including diameter and height from a melt; cooling and tempering the crystal with the larger than desired dimensions and after the cooling and tempering removing edge regions of the crystal with the larger than desired dimensions so that a diameter reduction and a height reduction of at least five percent occurs respectively and so that the crystal has the desired dimensions of diameter and height. No further tempering takes place after removing of the edge regions.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.