Title:
光弾性変調器を用いたフーリエ変換赤外線分光の複数の変調測定のためのデジタル信号処理技術
Document Type and Number:
Japanese Patent JP4090686
Kind Code:
B2
Abstract:
Digital signal proceessing (DSP) techiques for performing multiple modulation measurements with a polarization photoelastic modulator (PEM) in a step-scanning FT-IR spectrometer. The frequency and phase of the PEM drive signal are extracted from the digitized data collected for the actual measurement. This can then be used to perform the desired analysis of the polarization signals (e.g., CD,LD, DIRLD). This is accomplished by successively refining an initial estimate of the PEM frequency (typically starting at the nominal PEM frequency omega 0, or at the value determined from the previous step). This is done by using the current estimate of the PEM frequency to compute a phase error, and then using the computed phase error to refine the estimate of the PEM frequency. The phase errors are computed using different sets of samples in the sampling interval.
Inventors:
Carver Raoul
Application Number:
JP2000506498A
Publication Date:
May 28, 2008
Filing Date:
August 06, 1998
Export Citation:
Assignee:
Varian Australia Proprietary Limited
International Classes:
G01B9/02; G01J3/45; G01J3/447; G01J3/453; G01N21/17; G01N21/19; G01N21/21; G01N21/27; G01N21/35
Domestic Patent References:
| JP5045224A | ||||
| JP2276928A |
Other References:
C.J. Manning 外1名,“Step-Scanning Interferometer with Digital Signal Processing”,Applied Spectroscopy,1993年,Vol.47, No.9,pp.1345-1349
Attorney, Agent or Firm:
Sadao Kumakura
Fumiaki Otsuka
Takaki Nishijima
Hiroyuki Suda
Fumiaki Otsuka
Takaki Nishijima
Hiroyuki Suda