Patent · US Expired

Method for making low-stress large-volume not-(111)-oriented crystals with reduced stress birefringence and more uniform refractive index and crystals made thereby

US7303627B2 · kind B2 · utility

0Cited by

1References

10Claims

0Family size

Assignee

Schott AG · 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	Dec 4, 2007
Priority date	—
Expiry date	Jun 16, 2025

Classification

Technology area (CPC G)Physics
CPC primaryG02B5/3083
WIPO fieldSurface technology, coating
WIPO sectorChemistry

Abstract

A method is described for making an especially not-(111)-oriented low-stress large-volume crystal having a glide plane with reduced stress birefringence and more uniform refractive index. The method includes growing and tempering the crystal while heating and/or cooling to form a temperature gradient in order to relax stresses arising along the glide plane. During the tempering the heating and/or cooling occurs by heat transfer in a heat transfer direction and the heat transfer direction or temperature gradient is oriented at an angle of from 5° to 90° to the glide plane. Crystals with a uniform refractive index with variations of less than 0.025×10−6 (RMS value) are produced by the method.

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