Dual fiber optic spectrophotometer
AssigneeGuided Wave, Inc.
InventorDavid A. LeFebre
Life of this patent
Estimating the term…
Abstract
Spectrophotometric apparatus and methodology suitable for continuous and long-term use. The apparatus includes a monochromator providing pre-dispersed monochromatic light to the optical inputs of a pair of fiber optic cables and a translator for alternatively positioning the fiber optic cables at the same location with respect to the monochromator output. One of the cables conducts light to a sample under study while the other cable provides a reference for light intensity measurements. The methodology includes the steps of performing two scans through the monochromator output for each measurement on the sample. The fiber optic cables are moved between scans so that the cable employed in the latter scan occupies the former position of the cable employed in prior scan.
Claims51
A low noise spectrophotometer, comprising:
- monochromater means for providing a light beam of variable wavelength at an output;
- a first single strand fiber optic waveguide for conducting light from said monochromater means toward a sample;
- a second single strand fiber optic waveguide for conducting light;
- and
- translation means for alternatively positioning input ends of said first and second single strand fiber optic waveguides at the same position in space with respect to the output of said monochromater means, wherein said first and second fiber optic waveguides alternatively conduct light from said monochromater means to provide compensation for time and wavelength dependent fluctuations in the light intensity at the output of said monochromater means.
A low noise spectrophotometer for studying the optical properties of a sample, comprising:
- monochromater means for producing monochromatic light of variable wavelength at an output;
- first single strand fiber optic waveguide conducting light from said monochromater means toward said sample;
- second single strand fiber optic waveguide conducting light;
- third single strand fiber optic waveguide conducting light received from said sample;
- translation means for alternatively positioning optical input ends of said first and second fiber optic waveguides at the output of monochromater means;
- multiplexer means for alternatively transmitting light conducted through said second and third fiber optic waveguides;
- and
- detector means, optically coupled to an output of said multiplexer means, for providing an electrical signal proportional to a sensed light intensity.
A low noise spectrophotometer for studying the optical properties of a sample, comprising:
- monochromater means for producing monochromatic light of variable wavelength at an output;
- first single strand fiber optic waveguide for conducting light to said sample;
- second single strand fiber optic waveguide for conducting light;
- translation means for alternatively positioning optical input ends of said first and second single strand fiber optic waveguides at the same point with respect to the output of said monochromater means;
- third single strand fiber optic waveguide for conducting light received from said sample;
- first detector means, optically coupled to an output of said second fiber optic means, for producing an electrical signal proportional to a sensed light intensity;
- and
- second detector means, optically coupled to an output of said third fiber optic waveguide, for providing an electric signal proportional to a sensed intensity.
A spectrophotographic method to at least partially compensate anomalies within a spectrophotographic apparatus, said method employing a spectrophotographic apparatus having a monochromater, a first single strand fiber optic waveguide for directing light from an output of the monochromater to a sample, a second single strand fiber optic waveguide for directing light from the monochromater output and a translator for alternatively positioning optical inputs of the first and second fiber optic waveguides at the same predetermined location with respect to the monochromater output, the steps of said method comprising:
- scanning the wavelength of the light from the monochromater with the optical input of one of said fiber optic waveguides at said predetermined location;
- and
- positioning the optical input of the other of said fiber optic waveguides at the same predetermined location and again scanning the wavelength of the light from the monochromater, wherein light intensity data from the separate scans can be used for anomaly compensation.
An optical multiplexer, comprising:
- a base having a plurality of bores;
- a plurality of tubes respectively disposed within said bores;
- a plurality of first plugs, respectively disposed within said tubes, each configured to receive a first single strand fiber optic waveguide;
- a plurality of second plugs, respectively disposed within said tubes opposite first plugs so as to form gaps, each second plug configured to receive a second single strand fiber optic waveguide;
- a plurality of ferromagnetic elements respectively disposed within said gaps between a corresponding pair of first and second plugs;
- and
- a plurality of electromagnetic means for respectively forming independent electromagnetic fields within said gaps, wherein a magnetic field of a first polarity within a gap positions a corresponding ferromagnetic element within the gap so as to allow light passage between a pair of first and second plugs and a magnetic field of a second reversed polarity within a gap positions a corresponding ferromagnetic element within the gap so as to block light passage between the pair of first and second plugs.
Dependencies are inferred from the claim text.