Self-calibratable spectrum analyzer

Spectrophotometer apparatus for analyzing at least one sample, said apparatus comprising in combination:

• a radiation source for providing at least one beam of radiation having a predetermined spectral bandwidth characteristic;
• spectral band image converter means for providing a spectral image of said beam;
• flexible fiber optic probe means providing a predetermined optical coupling relationship between the radiation beam from said source, said sample and said converter means;
• plural optical electrical detectors disposed in an array, said detectors of said array being electrically scannable in a predetermined sequence,
• means for selectively irradiating said array of detectors with at least two portions of said spectral image, one of said portions being associated with a predetermined first spectral range, the other of said portions being associated with a predetermined second spectral range, said first and second ranges including mutually exclusive first and second spectral components, respectively, said first and second ranges having a common spectral component intermediate of said first and second spectral components, and
• means for calibrating said detectors for said first and second ranges, said means for calibrating including at least first and second narrow band optical filters and means for disposing said first and second filters in a predetermined manner in said radiation beam, said first and second filters being single and double narrow bandpass types, respectively, said first filter having a spectral transmission characteristic corresponding to one of the three said spectral components and said second filter having a spectral transmission characteristic corresponding to the other two said spectral components.

Spectrophotometer apparatus for analyzing at least one sample, said apparatus comprising in combination:

• a radiation source for providing first and second beams of radiation having predetermined spectral bandwidth characteristics;
• spectral band image converter means for providing spectral images of said beams;
• flexible fiber optic probe means providing a predetermined optical coupling relationship between said first radiation beam from said source and said sample and said converter means;
• fiber optic coupling means providing an optical coupling relationship directly between said second radiation beam and said converter means;
• plural optical electrical detectors disposed in an array, said detectors of said array being electrically scannable in a predetermined sequence,
• means for selectively irradiating said array of detectors with a first and second portion of each of said spectral images, one of said portions being associated with a predetermined first spectral range, the other of said portions being associated with a predetermined second spectral range, said first and second ranges including mutually exclusive first and second spectral components, respectively, said first and second ranges having a common spectral component intermediate of said first and second spectral components, and
• means for calibrating said detectors for said first and second ranges, said means for calibrating including at least first and second narrow band optical filters and means for disposing said first and second filters in a predetermined manner in said radiation beam, said first and second filters being single and double narrow bandpass types, respectively, said first filter having a spectral transmission characteristic corresponding to one of the three said spectral components and said second filter having a spectral transmission characteristic corresponding to the other two said spectral components.

The method of performing spectral analysis comprising the steps of:

• providing at least one beam of radiation having a predetermined spectral bandwidth characteristic;
• converting said beam to a spectral image;
• selectively irradiating a predetemined array of electrically scannable detectors with at least two portions of said spectral image, one of said portions being associated with a predetermined first spectral range, the other of said portions being associated with a predetermined second spectral range, said first and second ranges including mutually exclusive first and second spectral components, respectively, said first and second ranges having a common spectral component intermediate of said first and second spectral components, and
• calibrating said detectors for said first and second ranges, said step of calibrating including disposing at least first and second narrow band optical filters in a predetermined manner in the path of said radiation beam, said first and second filters being single and double narrow bandpass types, respectively, said first filter having a spectral transmission characteristic corresponding to one of the three said spectral components and said second filter having a spectral transmission characteristic corresponding to the other two said spectral components.