Spectrometer for the simultaneous measurement of intensity in various spectral regions

• US 4,993,834 A
• Filed: 09/25/1989
• Issued: 02/19/1991
• Est. Priority Date: 10/03/1988
• Status: Expired due to Fees

• Current Assignee: Fried Krupp GmbH Altendorfer
• Original Assignee: Fried Krupp GmbH (Thyssenkrupp AG)
• Inventors: Carlhoff, Christoph, Lorenzen, Claus-Jurgen, Nick, Klaus-Peter
• Primary Examiner(s): Evans, F. L.
• Assistant Examiner(s): HANTIS, KAREN
• Application Number:
  US07/411,820
• Time in Patent Office: 512 Days
• Field of Search: 356/328, 356/334, 356/305, 356/319, 356/326, 356/300, 350/96.19
• US Class Current: 356/328
• CPC Class Codes: G01J 2001/446 Photodiode
• CPC Class Codes: G01J 2001/448 Array [CCD]
• CPC Class Codes: G01J 2003/045 Sequential slits; Multiple slits
• CPC Class Codes: G01J 2003/1295 Plural entry slits, e.g. for different incidences
• CPC Class Codes: G01J 3/20 Rowland circle spectrometers
• CPC Class Codes: G01J 3/2803 using photoelectric array detector

Abstract

A polychromator in a Paschen-Runge mounting in which intensity measurements are made by means of a row of photodiodes. The spectral intensity distribution of at least two spectral regions on the Rowland circle is transmitted to the row of photodiodes by image conductors and is measured there.

Claims

1. In a polychromator having an entrance slit and a concave diffraction grating in a Paschen-Rung mounting on a Rowland circle, the improvement comprising:

a row of photodiodes; and

means, including image conductors coupling at least two areas on the Rowland circle and the row of photodiodes, for transmitting respective spectral regions of the at least two areas to the row of photodiodes so that the spectral intensity distribution of the at least two spectral regions is measured by the row of photodiodes, wherein each image conductor coupling an area of the Rowland circle and a photodiode is a cross section converter having on its one end a cross section equal to an acceptance cross section of the photodiode and on an opposite end a height equal to the spectral region at the area on the Rowland circle.

2. In a polychromator having an entrance slit and a concave diffraction grating in a Paschen-Runge mounting on a Rowland circle, the improvement comprising:

a row of photodiodes;

means, including image conductors coupling at least two areas on the Rowland circle and the row of photodiodes, for transmitting respective spectral regions at the at least two areas to the row of photodiodes so that the spectral intensity distribution of the at least two spectral regions is measured by the row photodiodes; and

intermediates imaging means for imaging an image of the entrance slit on the image conductors.

3. In a polychromator having an entrance slit and a concave diffraction grating in a Paschen-Runge mounted on a Rowland circle, the improvement comprising:

a row of photodiodes; and

means, including image conductors coupling at least two areas on the Rowland circle and the row of photodiodes, for transmitting respective spectral regions at the at least two areas to the row of photodiodes so that the spectral intensity distribution of the at least two spectral regions is measured by the row photodiodes, wherein said transmitting means comprises intermediate imaging means for imaging cross sections of said image conductors on the cross sections of respective photodiodes, each by way of a respective intermediate image.

4. In a polychromator having an entrance slit and a concave diffraction grating in a Paschen-Runge mounting on a Rowland circle, the improvement comprising:

a row of photodiodes; and

means, including image conductors coupling at least two areas on the Rowland circle and the row of photodiodes, for transmitting respective spectral regions at the at least two areas to the row of photodiodes so that the spectral intensity distribution of the at least two spectral regions is measured by the row photodiodes, wherein said transmitting means includes a first intermediate imaging means, coupled to a corresponding one of said image conductors, on the Rowland circle, for enlarging an image of the entrance slit corresponding to a cross section of said image conductor and a second intermediate imaging means, coupling said image conductor to a single photodiode of said row of photodiodes, for reducing the effective cross section of said image conductor at said row of photodiodes so that all light from said image conductor is received completely by the single photodiode.

5. In a polychromator having an entrance slit and a concave diffraction grating in a Paschen-Runge mounting on a Rowland circle, the improvement comprising:

a row of photodiodes; and

means, including image conductors coupling at least two areas on the Rowland circle and the row of photodiodes, for transmitting respective spectral regions at the at least two areas to the row of photodiodes so that the spectral intensity distribution of the at least two spectral regions is measured by the row photodiodes, wherein said transmitting means includes a plurality of intermediate imaging means, coupled to corresponding ones of said image conductors, for imaging the entrance slit on respective ones of said photodiodes so as to adjust the resolution of the spectral intensity detected by said photodiodes from spectral region to spectral region.

6. In a polychromator having an entrance slit and a concave diffraction grating in a Paschen-Runge mounting on a Rowland circle, the improvement comprising:

a row of photodiodes, a first part of said row being disposed at a first area on the Rowland circle so as to measure directly the spectral intensity distribution of a first spectral region at said first area at said first part of said row; and

means, including image conductors coupling a second area on the Rowland circle and a second part of said row of photodiodes, for transmitting a second spectral region at said second area to said second part of said row of photodiodes so that the spectral intensity distribution of the second spectral region is measured by said second part of said row of photodiodes.

7. A polychromator as in claim 6, wherein each image conductor coupling an area of the Rowland circle and a photodiode is a cross section converter having on its one end a cross section equal to an acceptance cross section of the photodiode and on an opposite end a height equal to the spectral region at the area on the Rowland circle.

8. A polychromator as defined in claim 6, further comprising intermediate imaging means for imaging an image of the entrance slit on the image conductors.

9. A polychromator as defined in claims 6, wherein said coupling means comprises intermediate imaging means for imaging cross sections of said image conductors on the cross sections of respective photodiodes, each by way of a respective intermediate image.

10. A polychromator as in claim 6, wherein said coupling means includes a first intermediate imaging means, coupled to a corresponding one of said image conductors, on the Rowland circle, for enlarging an image of the entrance slit corresponding to a cross section of said image conductor and a second intermediate imaging means, coupling said image conductor to a single photodiode of said row of photodiodes, for reducing the effective cross section of said image conductor at said row of photodiodes so that all light from said image conductor is received completely by the single photodiode.

11. A polychromator as in claim 6, wherein said coupling means includes a plurality of intermediate imaging means, coupled to corresponding ones of said image conductors, for imaging the entrance slit on respective ones of said photodiodes so as to adjust the resolution of the spectral intensity detected by said photodiodes from spectral region to spectral region.