Coating processes – Optical element produced
Patent
1995-06-07
1997-04-29
Lusignan, Michael
Coating processes
Optical element produced
356303, 356320, 356332, 427164, 4272481, B05D 506
Patent
active
056247095
ABSTRACT:
A differential spectrometry system detects very narrow-band spectral features, while providing much higher optical transmittance and signal-to-noise ratios than prior optical-filter-based spectrometer systems. A plurality of light detectors (10a, 10b) detect light that falls within respective wide wavebands. The wide wavebands have overlapping and non-overlapping portions, one of which is the desired narrow waveband. The detector outputs are operated upon to produce an output signal (22) which includes substantially only the desired narrow waveband. In the preferred embodiment, the light detectors (10a, 10b) are implemented with a pair of optical detectors (30a, 30b) and respective optical interference filters (24a, 24b). The filters have substantially identical cut-off wavelengths (.lambda..sub.2) and cut-on wavelengths that are shifted by .DELTA..lambda. with respect to each other (.lambda..sub.1 and (.lambda..sub.1 +.DELTA..lambda.), respectively). The detector outputs are differenced with an operational amplifier (33), so that detector signals resulting from spectral features common to both detectors (30a, 30b) are canceled. The remaining signal (36) varies according to the amount of light that falls between wavelength boundaries [.lambda..sub.1 and (.lambda..sub.1 +.DELTA..lambda.)]. A preferred method of fabricating the optical interference filters (24a, 24b) is also provided.
REFERENCES:
patent: 4262056 (1981-04-01), Hubler et al.
patent: 4317137 (1982-02-01), Tompkins
patent: 4545646 (1985-10-01), Chern et al.
patent: 5181143 (1993-01-01), Southwell
patent: 5294288 (1994-03-01), Melpolder et al.
patent: 5425964 (1995-06-01), Southwell et al.
H. A. Macleod, Thin-Film Optical Filters, Second Edition, MacMillan Publishing Co., New York (1986), pp. 234-313.
Peterson Cathy M.
Stannard John E.
Walter Geoffrey A.
West Roger A.
Denson-Low W. K.
Lusignan Michael
Santa Barbara Research Center
Schubert W. C.
LandOfFree
High resolution differential spectrometry system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High resolution differential spectrometry system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High resolution differential spectrometry system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-704229