Optical system for a multidetector array spectrograph

• US 4,966,458 A
• Filed: 05/26/1989
• Issued: 10/30/1990
• Est. Priority Date: 05/06/1988
• Status: Expired due to Fees

• Current Assignee: Milton ROY Company St Petersburg Florida
• Original Assignee: Milton Roy Company
• Inventors: King, Edward, Burns, Richard, McCarthy, Cornelius, Defendorf, James
• Primary Examiner(s): Evans, F. L.
• Application Number:
  US07/357,980
• Time in Patent Office: 522 Days
• Field of Search: 356/51, 356/303, 356/305, 356/319, 356/320, 356/323, 356/325, 356/326, 356/328, 356/332, 356/334
• US Class Current: 356/328
• CPC Class Codes: G01J 2003/045 Sequential slits; Multiple slits
• CPC Class Codes: G01J 2003/102 Plural sources
• CPC Class Codes: G01J 2003/1204 Grating and filter
• CPC Class Codes: G01J 2003/1295 Plural entry slits, e.g. for different incidences
• CPC Class Codes: G01J 2003/1828 with order sorter or prefilter
• CPC Class Codes: G01J 2003/425 Reflectance
• CPC Class Codes: G01J 3/04 Slit arrangements slit adjustment
• CPC Class Codes: G01J 3/12 Generating the spectrum; Monochromators
• CPC Class Codes: G01J 3/1838 Holographic gratings
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01J 3/4406 Fluorescence spectrometry
• CPC Class Codes: G01J 3/443 Emission spectrometry
• CPC Class Codes: G01N 2021/174 either absorption-reflection or emission-fluorescence
• CPC Class Codes: G01N 2021/3129 Determining multicomponents by multiwavelength light

Abstract

An optical system for a multidetector array spectrophotometer which includes multiple light sources for emitting light of selected wavelength ranges and means for selectively transmitting the selected wavelength ranges of light to respective slits of a multi-slit spectrogrpah for multiple wavelength range detection. The spectrograph has two or more slits which direct the selected wavelength ranges of the light spectra to fall upon a dispersive and focusing system which collects light from each slit, disperses the light by wavelength and refocuses the light at the positions of a single set of detectors.

Claims

1. An apparatus for the measurement of light intensity by wavelength comprising:

a concave grating for the dispersion and focusing of light by wavelength;

said concave grating having a preferred plane to disperse light and having a normal lying in said preferred plane relative to which angles may be defined as rotations around a rotation point located at the intersection of said normal and the surface of said grating,

detector means optically coupled to said concave grating for the conversion of light energy to electrical energy indicative of said light intensity;

said detector means comprising a plurality of light sensitive elements, said detector means being positioned such that said light sensitive elements are present at or between angles of 8.3 and 14.4 degrees from the grating normal,

a first port for entrance of light to the apparatus;

the center of said first port being at a specific first angle chosen to be between -0.3 and -5.4 degrees from the grating normal, the location of said first port along a line defined by said chosen first angle and said rotation point selected so as to obtain optimum focus of light entering at said first port at said detector means by said grating, and

a second port for entrance of light to the apparatus;

the center of said second port being at a specific second angle chosen to be between -0.3 and -5.4 degrees from the grating normal, the location of said second port along a line defined by said chosen second angle and said rotation point selected so as to obtain optimum focus of light entering at said second port at said detector means by said grating.

2. Apparatus according to claim 1 wherein

said first chosen angle for said first port is between -5.2 and -5.4 degrees from the grating normal, and

said second chosen angle for said second port is between -0.3 and -0.5 degrees from the grating normal.

3. Apparatus according to claim 2 wherein

said first chosen angle is -5.336 degrees from the grating normal, and

said second chosen angle is -0.421 degrees from the grating normal.

4. Apparatus according to claim 1 further comprising at least one additional port for entrance of light to the apparatus;

the center of said one additional port being at a specific additional angle chosen to be between -0.3 and -0.54 degrees from the grating normal, the location of said additional port along a line defined by said chosen additional angle and said rotation point selected so as to obtain optimum focus of light entering at said additional port at said detector means by said grating.