EP 1019703 A1 20000719 - INTERFEROMETRIC METHOD AND APPARATUS
Title (en)
INTERFEROMETRIC METHOD AND APPARATUS
Title (de)
INTERFEROMETRISCHES VERFAHREN UND VORRICHTUNG
Title (fr)
PROCEDE ET APPAREIL INTERFEROMETRIQUES
Publication
Application
Priority
- US 9819855 W 19980923
- US 94284897 A 19971002
Abstract (en)
[origin: WO9918424A1] Interferometric apparatus and method for measuring and monitoring intrinsic optical properties of a gas, especially the reciprocal dispersive power of the gas, so that information about the gas properties can be used in downstream applications, such as interferometric distance measuring instruments, to increase accuracy by correcting for refractive index of the gas and especially environmental and air turbulence effects in the measurement path. The apparatus comprises a concentric measurement cell having an inner chamber containing a vacuum surrounded by an outer occupied by the gas. Wavelength selective mirrors are arranged at each end of the measurement cell and operate in conjunction with plane mirror interferometers to change the phase of orthogonally polarized components of light beams of different wavelength introduced in the measurement cell from opposite ends of the cell. Preferably, the polarized components are frequency-shifted to facilitate the generation of heterodyne and superheterodyne signals which contain information about the intrisinc optical properties of the gas. The heterodyne and superheterodyne signals are electronically analyzed by a general purpose computer programmed for that purpose or from a specially programmed microprocessor.
IPC 1-7
IPC 8 full level
G01B 9/02 (2006.01); G01N 21/45 (2006.01)
CPC (source: EP)
G01B 9/02002 (2013.01); G01B 9/02007 (2013.01); G01B 9/02027 (2013.01); G01B 9/0207 (2013.01); G01N 21/45 (2013.01); G01B 2290/45 (2013.01); G01B 2290/70 (2013.01)
Citation (search report)
See references of WO 9918424A1
Designated contracting state (EPC)
DE NL
DOCDB simple family (publication)
WO 9918424 A1 19990415; WO 9918424 A9 20080619; EP 1019703 A1 20000719; JP 2001519527 A 20011023; JP 3626907 B2 20050309
DOCDB simple family (application)
US 9819855 W 19980923; EP 98948466 A 19980923; JP 2000515169 A 19980923