公开(公告)号：FR2833704A1

公开(公告)日：2003-06-20

申请号：FR0116097

申请日：2001-12-13

Applicant: CORNING INC

Inventor： PELL MICHAEL ,  MAYOLET ALEXANDRE ,  TIMOFEEV NIKOLAY

IPC: C30B11/00 ,  G01N21/33 ,  G01N21/35 ,  G02B1/02

Abstract: A low lead impurity level in a below 200 nm transmitting optical fluoride crystal is determined by transmitting a transmission test wavelength of 200-210 nm through below 200 nm wavelength transmitting optical fluoride crystal light transmission path length and measuring the transmission of the 200-210 nm test wavelength to provide a lead ppb impurity level measurement less than 900 ppb. Detection of a low lead impurity level in a below 200 nm transmitting optical fluoride crystal, comprises providing a below 200 nm wavelength transmitting optical fluoride crystal (20) having a crystal light transmitting path length (21). The below 200 nm wavelength transmits optical fluoride crystal light transmission path length \-2 mm. A light transmission spectrophotometer is provided having a lamp for producing a transmission test wavelength of 200-210 nm and a transmission detector (28) for measuring transmission of the test wavelength. The transmission test wavelength of 200-210 nm is transmitted through below 200 nm wavelength transmitting optical fluoride crystal light transmission path length and measuring the transmission of the 200-210 nm test wavelength through the path length to provide a lead ppb impurity level measurement less than 900 ppb. An Independent claim is also included for a method of making a below 200 nm wavelength optical element having an absorption coefficient at 200-210 nm of less than 0.0017 cm .

公开(公告)号：FR2833704B1

公开(公告)日：2004-03-12

申请号：FR0116097

申请日：2001-12-13

Applicant: CORNING INC

Inventor： PELL MICHAEL ,  MAYOLET ALEXANDRE ,  TIMOFEEV NIKOLAY

IPC: C30B11/00 ,  G01N21/33 ,  G01N21/35 ,  G02B1/02