Combined spatial filter and relay systems in rotating compensator ellipsometer/polarimeter

• US 7,245,376 B2
• Filed: 11/22/2005
• Issued: 07/17/2007
• Est. Priority Date: 09/20/1995
• Status: Expired due to Term

• Current Assignee: J.A. Woollam Co., Inc.
• Original Assignee: J.A. Woollam Co., Inc.
• Inventors: Liphardt, Martin M., He, Ping, Hale, Jeffrey S., Herzinger, Craig M., Johs, Blaine D., Green, Steven E., Woollam, John A.
• Primary Examiner(s): Chowdhury; Tarifur
• Assistant Examiner(s): Akanbi; Isiaka O.
• Application Number:
  US11/284,213
• Publication Number:
  US 20060268272A1
• Time in Patent Office: 602 Days
• Field of Search: 356/369
• US Class Current: 356/369
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/021 using plane or convex mirrors, parallel phase plates, or particular reflectors
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/0243 having a through-hole enabling the optical element to fulfil an additional optical function, e.g. a mirror or grating having a throughhole for a light collecting or light injecting optical fiber
• CPC Class Codes: G01J 4/00 Measuring polarisation of light
• CPC Class Codes: G01N 2021/213 Spectrometric ellipsometry
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence
• CPC Class Codes: G01N 21/211 Ellipsometry optical thickness measurement G01B11/06
• CPC Class Codes: G02B 17/008 Systems specially adapted to form image relays or chained systems

Abstract

Low aberration relay systems modified to perform as spatial filters in rotating compensator ellipsometer, polarimeter and the like systems.

Claims

1. A spectroscopic rotating compensator material system investigation system comprising a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and at least one detector system which contains a multiplicity of detector elements, said spectroscopic rotating compensator material system investigation system further comprising at least one compensator(s) positioned at a location selected from the group consisting of:

before said stage for supporting a material system;

after said stage for supporting a material system; and

both before and after said stage for supporting a material system;

such that when said spectroscopic rotating compensator material system investigation system is used to investigate a material system present on said stage for supporting a material system, said analyzer and polarizer are maintained essentially fixed in position and at least one of said at least one compensator(s) is caused to continuously rotate while a polychromatic beam of electromagnetic radiation produced by said source of a polychromatic beam of electromagnetic radiation is caused to pass through said polarizer and said compensator(s), said polychromatic beam of electromagnetic radiation being also caused to interact with said material system, pass through said analyzer and interact with said dispersive optics such that a multiplicity of essentially single wavelengths are caused to simultaneously enter a corresponding multiplicity of detector elements in said at least one detector system;

said spectroscopic rotating compensator material system investigation system being further characterized by the presence of at least one combined spatial filter and relay system positioned before and/or after said stage for supporting a material system, wherein said spatial filter causes a polychromatic beam of electromagnetic radiation directed thereat to pass therethrough and exit therefrom as an effective point source, and wherein said relay system comprises at least one reflective concave surface and at least one reflective convex surface.

2. A spectroscopic rotating compensator material system investigation system as in claim 1, in which the at least one combined spatial filter and relay system comprises:

a) an aperture;

b) a flat mirror;

c) a concave spherical mirror having at least one concave spherical surface; and

d) a convex spherical mirror having at least one convex spherical surface;

said elements being arranged such that electromagnetic radiation from said aperture is caused to approach the flat mirror and reflect therefrom onto a first location of a concave surface of said concave spherical mirror, reflect from said first location onto a convex spherical surface of said convex spherical mirror and reflect therefrom onto a second location of said concave surface of said concave spherical mirror from which it reflects as a converging beam of electromagnetic radiation.

3. A spectroscopic rotating compensator material system investigation system as in claim 2, in which the at least one combined spatial filter and relay system which further comprises a second flat mirror positioned to intercept and reflect electromagnetic radiation reflected from said second location of said concave surface of said concave spherical mirror as a converging beam of electromagnetic radiation.

4. A spectroscopic rotating compensator material system investigation system as in claim 1, in which the at least one combined spatial filter and relay system comprises five elements:

a) an aperture;

b) a first flat mirror;

c) a concave spherical mirror having at least one concave spherical surface;

d) a convex spherical mirror having at least one convex spherical surface; and

e) a second flat mirror;

said elements being arranged such that electromagnetic radiation from said aperture is caused to approach the first flat mirror and reflect therefrom onto a first location of a concave surface of said concave spherical mirror, reflect from said first location onto a convex spherical surface of said convex spherical mirror and reflect therefrom onto a second location of said concave surface of said concave spherical mirror from which it reflects onto said second flat mirror positioned to intercept and reflect electromagnetic radiation reflected from said second location of said concave surface of said concave spherical mirror as a converging beam of electromagnetic radiation.

5. A spectroscopic rotating compensator material system investigation system as in claim 4 in which the combined spatial filter and relay system provides that electromagnetic radiation from said aperture is caused to approach the first flat mirror at a 45 degree angle, and reflect from said second flat mirror at a 45 degree angle.

12. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 2 which further comprises a coating on at least one of the concave, convex and flat mirrors which changes the intensity vs. wavelength plot of a reflected electromagnetic beam relative to an incident beam.

13. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 3 which further comprises a coating on at least one at the concave, convex and flat mirrors which changes the intensity vs. wavelength plot of a reflected electromagnetic beam relative to an incident beam.

14. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 4 which further comprises a coating on at least one of the concave, convex, first flat and second flat mirrors which changes the intensity vs. wavelength plot of a reflected electromagnetic beam relative to an incident beam.

17. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 1, in which said aperture hole is actually or effectively non-circular.

18. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 2, in which said aperture is actually or effectively non-circular.

19. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 4, in which said aperture is actually or effectively non-circular.

26. A spectroscopic rotating compensator material system investigation system as in claim 1 in which the rotating compensator is of a type selected from the group consisting of:

Berek-type with optical axis essentially perependicular to a surface thereof;

non-Berek-type with an optical axis essentially parallel to a surface thereof;

zero-order wave plate;

zero-order waveplate constructed from two multiple order waveplates;

a sequential plurality of zero-order waveplates, each constructed each from a plurality of multiple order waveplates;

rhomb;

polymer;

achromatic crystal; and

pseudo-achromatic;

and in which said compensator provides retardance within a range of thirty (30.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) minimum wavelength is less than/equal to one-hundred-ninety (190) and maximum wavelength greater than/equal to seventeen-hundred (1700) nanometers;

b) minimum wavelength is less than/equal to two-hundred-twenty (220) and maximum wavelength MAXW greater than/equal to one-thousand (1000) nanometers;

c) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) range where (MAXW)/(MINW) is at least four-and-one-half (4.5);

or said compensator provides retardance within a range of seventy-five (75.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) between one-hundred-ninety (190) and seven-hundred-fifty (750) nanometers;

b) between two-hundred-forty-five (245) and nine-hundred (900) nanometers;

c) between three-hundred-eighty (380) and seventeen-hundred (1700) nanometers;

d) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) wherein the ratio of (MAXW)/(MINW) is at least one-and-eight-tenths.

27. A spectroscopic rotating compensator material system investigation system as in claim 1, in which the rotating compensator comprises a selection from the group consisting of:

comprised of a combination of at least two zero-order waveplates, said zero-order waveplates and having their respective fast axes rotated to a position offset from zero or ninety degrees with respect to one another;

comprised of a combination of at least a first and a second effective zero-order wave plate, said first effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, and said second effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another;

the fast axes of the multiple order waveplates in said second effective zero-order wave plate being rotated to a position at a nominal forty-five degrees to the fast axes of the multiple order waveplates and in said first effective zero-order waveplate;

comprised of a combination of at least a first and a second effective zero-order wave plate, said first effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, and said second effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another;

the fast axes of the multiple order wave plates in said second effective zero-order wave plate being rotated to a position away from zero or ninety degrees with respect to the fast axes of the multiple order waveplates and in said first effective zero-order waveplate; and

comprised of a combination of at least one zero-order waveplate and at least one effective zero-order waveplate, said effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, the fast axes of the multiple order waveplates in said effective zero-order wave plate being rotated to a position away from zero or ninety degrees with respect to the fast axis of the zero-order waveplate;

Berek-type with optical axis essentially perependicular to a surface thereof;

non-Berek-type with an optical axis essentially parallel to a surface thereof;

zero-order wave plate;

zero-order waveplate constructed from two multiple order waveplates;

a sequential plurality of zero-order waveplates, each constructed each from a plurality of multiple order waveplates;

rhomb;

polymer;

achromatic crystal; and

pseudo-achromatic;

and in which said compensator provides retardance within a range of thirty (30.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) minimum wavelength is less than/equal to one-hundred-ninety (190) and maximum wavelength greater than/equal to seventeen-hundred (1700) nanometers;

b) minimum wavelength is less than/equal to two-hundred-twenty (220) and maximum wavelength MAXW greater than/equal to one-thousand (1000) nanometers;

c) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) range where (MAXW)/(MINW) is at least four-and-one-half (4.5);

or said compensator provides retardance within a range of seventy-five (75.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) between one-hundred-ninety (190) and seven-hundred-fifty (750) nanometers;

b) between two-hundred-forty-five (245) and nine-hundred (900) nanometers;

c) between three-hundred-eighty (380) and seventeen-hundred (1700) nanometers;

d) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) wherein the ratio of (MAXW)/(MINW) is at least one-and-eight-tenths.

31. A spectroscopic ellipsometer or polarimeter system as in claim 1 in which the multiplicity of detector elements are arranged in a selection from the group consisting of:

one-dimensional array;

two-dimensional array; and

three-dimensional array.

6. A spectroscopic rotating compensator material system investigation system comprising a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and at least one detector system which contains a multiplicity of detector elements, said spectroscopic rotating compensator material system investigation system further comprising at least one compensator(s) positioned at a location selected from the group consisting of:

before said stage for supporting a material system;

after said stage for supporting a material system; and

both before and after said stage for supporting a material system;

such that when said spectroscopic rotating compensator material system investigation system is used to investigate a material system present on said stage for supporting a material system, said analyzer and polarizer are maintained essentially fixed in position and at least one of said at least one compensator(s) is caused to continuously rotate while a polychromatic beam of electromagnetic radiation produced by said source of a polychromatic beam of electromagnetic radiation is caused to pass through said polarizer and said compensator(s), said polychromatic beam of electromagnetic radiation being also caused to interact with said material system, pass through said analyzer and interact with said dispersive optics such that a multiplicity of essentially single wavelengths are caused to simultaneously enter a corresponding multiplicity of detector elements in said at least one detector system;

said spectroscopic rotating compensator material system investigation system being further characterized by the presence of first and second relay systems positioned before and after said stage for supporting a material system, respectively;

said first and second relay systems, each comprising four elements;

a) a first flat mirror;

b) a concave spherical mirror having at least one concave spherical surface;

c) a convex spherical mirror having at least one convex spherical surface; and

d) a second flat mirror;

said elements being arranged such that electromagnetic radiation is caused to approach the first flat mirror and reflect therefrom onto a first location of a concave surface of said concave spherical mirror, reflect from said first location onto a convex spherical surface of said convex spherical mirror and reflect therefrom onto a second location of said concave surface of said concave spherical mirror from which it reflects onto said second flat mirror positioned to intercept and reflect electromagnetic radiation reflected from said second location of said concave surface of said concave spherical mirror as a converging beam of electromagnetic radiation;

said material system being positioned between said first and second relay systems;

said first relay system being positioned to relay electromagnetic radiation from the source thereof, which passes through an aperture, and direct it onto a surface of said material system at an oblique angle of incidence, and said second relay system being positioned to receive electromagnetic radiation reflected from the material system and pass it on to said detector;

the propagation direction of electromagnetic radiation entering and exiting each of said first and second relay systems being substantially unchanged by passing therethrough;

said system being further characterized in that a plane formed by the locus of the electromagnetic radiation passing through the first relay system is oriented 90 degrees to a plane formed by the locus of the electromagnetic radiation passing through the second relay system, the purpose being to minimize effects of said first and second relay systems on a polarization state of said electromagnetic radiation which passes through both thereof.

7. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 6 which further comprises at least one selection from the group consisting of:

a) a fiber optic between said source and material system; and

b) a fiber optic between said material system and detector.

8. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 7 which further comprises at least two compensators between said source and detector.

15. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 6 which further comprises a coating on at least one of the concave, convex, first flat and second flat mirrors which changes the intensity vs. wavelength plot of a reflected electromagnetic beam relative to an incident beam.

20. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 6, in which said aperture is actually or effectively non-circular.

9. A spectroscopic rotating compensator material system investigation system comprising a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and at least one detector system which contains a multiplicity of detector elements, said spectroscopic rotating compensator material system investigation system further comprising at least one compensator(s) positioned at a location selected from the group consisting of:

before said stage for supporting a material system;

after said stage for supporting a material system; and

both before and after said stage for supporting a material system;

such that when said spectroscopic rotating compensator material system investigation system is used to investigate a material system present on said stage for supporting a material system, said analyzer and polarizer are maintained essentially fixed in position and at least one of said at least one compensator(s) is caused to continuously rotate while a polychromatic beam of electromagnetic radiation produced by said source of a polychromatic beam of electromagnetic radiation is caused to pass through said polarizer and said compensator(s), said polychromatic beam of electromagnetic radiation being also caused to interact with said material system, pass through said analyzer and interact with said dispersive optics such that a multiplicity of essentially single wavelengths are caused to simultaneously enter a corresponding multiplicity of detector elements in said at least one detector system;

said spectroscopic rotating compensator material system investigation system being further characterized by the presence of;

first and second relay systems, each thereof comprising four elements;

a) a first flat mirror;

b) a concave spherical mirror having at least one concave spherical surface;

c) a convex spherical mirror having at least one convex spherical surface; and

d) a second flat mirror;

said elements being arranged such that electromagnetic radiation is caused to approach the first flat mirror and reflect therefrom onto a first location of a concave surface of said concave spherical mirror, reflect from said first location onto a convex spherical surface of said convex spherical mirror and reflect therefrom onto a second location of said concave surface of said concave spherical mirror from which it reflects onto said second flat mirror positioned to intercept and reflect electromagnetic radiation reflected from said second location of said concave surface of said concave spherical mirror as a converging beam of electromagnetic radiation;

said first and second relay systems being positioned on the same side of the material system;

the propagation direction of electromagnetic radiation entering and exiting each of said first and second relay systems being substantially unchanged by passing therethrough;

said system being further characterized in that a plane formed by the locus of the electromagnetic radiation passing through the first relay system is oriented 90 degrees to a plane formed by the locus of the electromagnetic radiation passing through the second relay system, the purpose being to minimize effects of said first and second relay systems on a polarization state of said electromagnetic radiation which passes through both thereof.

10. A spectroscopic rotating compensator material system investigation systemystem for investigating a material system as in claim 9 which further comprises at least one selection from the group consisting of:

a) a fiber optic between said source and material system; and

b) a fiber optic between said material system and detector.

11. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 10 which further comprises at least two compensators between said source and detector.

16. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 9 which further comprises a coating on at least one of the concave, convex, first flat and second flat mirrors which changes the intensity vs. wavelength plot of a reflected electromagnetic beam relative to an incident beam.

21. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 9, in which said aperture is actually or effectively non-circular.

32. A spectroscopic ellipsometer or polarimeter system as in claim 9 in which the multiplicity of detector elements are arranged in a selection from the group consisting of:

one-dimensional array;

two-dimensional array; and

three-dimensional array.

22. A spectroscopic rotating compensator material system investigation system comprising a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and at least one detector system which contains a multiplicity of detector elements, said spectroscopic rotating compensator material system investigation system further comprising at least one compensator(s) positioned at a location selected from the group consisting of:

before said stage for supporting a material system;

after said stage for supporting a material system; and

both before and after said stage for supporting a material system;

such that when said spectroscopic rotating compensator material system investigation system is used to investigate a material system present on said stage for supporting a material system, said analyzer and polarizer are maintained essentially fixed in position and at least one of said at least one compensator(s) is caused to continuously rotate while a polychromatic beam of electromagnetic radiation produced by said source of a polychromatic beam of electromagnetic radiation is caused to pass through said polarizer and said compensator(s), said polychromatic beam of electromagnetic radiation being also caused to interact with said material system, pass through said analyzer and interact with said dispersive optics such that a multiplicity of essentially single wavelengths are caused to simultaneously enter a corresponding multiplicity of detector elements in said at least one detector system;

said spectroscopic rotating compensator material system investigation system being further characterized by, between said source of a polychromatic beam and said detector, the presence of;

a relay system comprising three elements;

a) a flat mirror;

b) a concave spherical mirror having at least one concave spherical surface;

c) a convex spherical mirror having at least one convex spherical surface;

said elements being arranged such that electromagnetic radiation is caused to approach the flat mirror and reflect therefrom onto a first location of a concave surface of said concave spherical mirror, reflect from said first location onto a convex spherical surface of said convex spherical mirror and reflect therefrom onto a second location of said concave surface of said concave spherical mirror from which it reflects as a converging beam of electromagnetic radiation;

said system being further characterized by the presence of an aperture present prior to said flat mirror, through which aperture said beam of electromagnetic radiation passes before interacting with said flat mirror, and from which aperture said polychromatic beam of electromagnetic radiation exits as an effective point source.

23. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 22 which further comprises at least one selection from the group consisting of:

a) a fiber optic between said source and material system; and

b) a fiber optic between said material system and detector.

24. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 22 which further comprises a coating on at least one of the concave, convex, and flat mirror which changes the intensity vs. wavelength plot of a reflected electromagnetic beam relative to an incident beam.

25. A spectroscopic rotating compensator material system investigation system for investigating a material system as in claim 22, in which said aperture is actually or effectively non-circular.

28. A spectroscopic rotating compensator material system investigation system comprising a source of a polychromatic beam of electromagnetic radiation, a first aperture, a second aperture, a fixed polarizer, a rotating compensator, a third aperture, a forth aperture, a fifth aperture, a stage for supporting a material system, a sixth aperture, a seventh aperture, an eighth aperture, a fixed analyzer, a ninth aperture, a substantially achromatic lens, an optical fiber and at least one detector system which comprises a dispersive element and a multiplicity of detector elements, there optionally being a UV filter present between said source of a polychromatic beam of electromagnetic radiation and said stage for supporting a material system;

such that when said spectroscopic rotating compensator material system investigation system is used to investigate a material system present on said stage for supporting a material system, said fixed analyzer and fixed polarizer are maintained essentially fixed in position and said rotating compensator is caused to continuously rotate while a polychromatic beam of electromagnetic radiation produced by said source of a polychromatic beam of electromagnetic radiation is sequentially caused to pass through said first aperture, second aperture, fixed polarizer, rotating compensator, third aperture, forth aperture, fifth aperture, said polychromatic beam of electromagnetic radiation then interact with a material system placed on said stage for supporting a material system and sequentially passing through said sixth aperture, seventh aperture, eighth aperture, fixed analyzer, ninth aperture, said substantially achromatic lens, enter said optical fiber and there via enter said detector system;

said spectroscopic rotating compensator material system investigation system being further characterized by the presence of at least one combined spatial filter and relay system positioned before and/or after said stage for supporting a material system.

29. A spectroscopic rotating compensator material system investigation system as in claim 28 in which the rotating compensator comprises a selection from the group consisting of:

comprised of a combination of at least two zero-order waveplates, said zero-order waveplates and having their respective fast axes rotated to a position offset from zero or ninety degrees with respect to one another;

comprised of a combination of at least a first and a second effective zero-order wave plate, said first effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, and said second effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another;

the fast axes of the multiple order waveplates in said second effective zero-order wave plate being rotated to a position at a nominal forty-five degrees to the fast axes of the multiple, order waveplates and in said first effective zero-order waveplate;

comprised of a combination of at least a first and a second effective zero-order wave plate, said first effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, and said second effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another;

the fast axes of the multiple order waveplates in said second effective zero-order wave plate being rotated to a position away from zero or ninety degrees with respect to the fast axes of the multiple order waveplates and in said first effective zero-order waveplate; and

comprised of a combination of at least one zero-order waveplate and at least one effective zero-order waveplate, said effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, the fast axes of the multiple order waveplates in said effective zero-order wave plate being rotated to a position away from zero or ninety degrees with respect to the fast axis of the zero-order waveplate;

Berek-type with optical axis essentially perependicular to a surface thereof;

non-Berek-type with an optical axis essentially parallel to a surface thereof;

zero-order wave plate;

zero-order waveplate constructed from two multiple order waveplates;

a sequential plurality of zero-order waveplates, each constructed each from a plurality of multiple order waveplates;

rhomb;

polymer;

achromatic crystal; and

pseudo-achromatic;

and in which said compensator provides retardance within a range of thirty (30.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) minimum wavelength is less than/equal to one-hundred-ninety (190) and maximum wavelength greater than/equal to seventeen-hundred (1700) nanometers;

b) minimum wavelength is less than/equal to two-hundred-twenty (220) and maximum wavelength MAXW greater than/equal to one-thousand (1000) nanometers;

c) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) range where (MAXW)/(MINW) is at least four-and-one-half (4.5);

or said compensator provides retardance within a range of seventy-five (75.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) between one-hundred-ninety (190) and seven-hundred-fifty (750) nanometers;

b) between two-hundred-forty-five (245) and nine-hundred (900) nanometers;

c) between three-hundred-eighty (380) and seventeen-hundred (1700) nanometers;

d) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) wherein the ratio of (MAXW)/(MINW) is at least one-and-eight-tenths.

30. A spectroscopic rotating compensator material system investigation system as in claim 28, in which:

said first aperture is a pinhole, through which a portion of the polychromatic beam of electromagnetic radiation passes, with a nominal internal diameter of between 100 and 600 microns;

said second aperture through which a portion of the polychromatic beam of electromagnetic radiation passes, has a nominal internal diameter has a nominal internal diameter of 3 to 3.5 millimeters;

said third aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 3.5 millimeters;

said forth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 3.75 millimeters;

said fifth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 4.8 millimeters;

said sixth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 4.8 millimeters;

said seventh aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 3.75 millimeters;

an eighth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 3.5 millimeters;

said ninth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has an adjustible internal diameter.

33. A spectroscopic ellipsometer or polarimeter system as in claim 28 in which the multiplicity of detector elements are arranged in a selection from the group consisting of:

one-dimensional array;

two-dimensional array; and

three-dimensional array.