Spectrally encoded miniature endoscopic imaging probe

• US 9,295,391 B1
• Filed: 11/10/2000
• Issued: 03/29/2016
• Est. Priority Date: 11/10/2000
• Status: Active Grant

• Current Assignee: The General Hospital Corporation (Mass General Brigham, Inc.)
• Original Assignee: The General Hospital Corporation (Mass General Brigham, Inc.)
• Inventors: Tearney, Guillermo J., Bouma, Brett Eugene, Shishkov, Milen Stefanov, Rosen, Jonathan Jay
• Primary Examiner(s): KISH, JAMES M
• Application Number:
  US09/709,162
• Time in Patent Office: 5,618 Days
• Field of Search: 600/473, 600/475, 600/476, 600/477, 600/478, 600/160, 600/129, 600/407, 600/310, 356/450
• US Class Current: 1/1
• CPC Class Codes: A61B 1/00096 Optical elements
• CPC Class Codes: A61B 1/0017 Details of single optical fibres, e.g. material or cladding
• CPC Class Codes: A61B 1/043 for fluorescence imaging
• CPC Class Codes: A61B 1/07 using light-conductive means, e.g. optical fibres
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0062 Arrangements for scanning
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: G02B 21/0036 Scanning details, e.g. scanning stages
• CPC Class Codes: G02B 21/0048 scanning mirrors, e.g. rotating or galvanomirrors, MEMS mirrors
• CPC Class Codes: G02B 21/0064 multi-spectral or wavelength-selective arrangements, e.g. wavelength fan-out, chromatic profiling G02B21/0076 takes precedence

Abstract

A spectrally encoded endoscopic probe having high resolution and small diameter comprising at least one flexible optical fiber; an energy source; a grating through which said energy is transmitted such that the energy spectrum is dispersed; a lens for focusing the dispersed energy spectrum onto a sample such that the impingement spot for each wavelength is a separate position on the sample, the wavelength spectrum defining a wavelength encoded axis; means for mechanically scanning the sample with focused energy in a direction perpendicular to the wavelength encoded axis; a means for receiving energy reflected from the sample; and, a means for detecting the received reflected energy. The probe grating and lens delivers a beam of multi-spectral light having spectral components extending in one dimension across a target region and which is moved to scan in another direction. The reflected spectrum is measured to provide two dimensional imaging of the region.

Claims

1. An apparatus for obtaining information associated with an anatomical structure, comprising:

a housing;

at least one lens that is different from the housing, and which is configured to provide there through electro-magnetic radiation, wherein the electro-magnetic radiation is provided by at least one of a broadband source or a wavelength tuned source;

an optical waveguide configured to transmit the electro-magnetic radiation from the structure;

at least one further arrangement including a computer which is structured to obtain the information based on the electro-magnetic radiation obtained from the structure, wherein the information is at least one of a two-dimensional image or a three dimensional image; and

a dispersive arrangement including a grating which is configured to receive at least one portion of the electro-magnetic radiation and forward a dispersed radiation thereof to at least one section of the structure regarding which the information is being obtained, wherein the grating has a groove density that is at least 1200 lines/mm, wherein the lens and the dispersive arrangement are provided within at least one portion of the housing and in an optical path between the optical waveguide and a location of the apparatus at which the electro-magnetic radiation is received from the anatomical structure, and wherein the at least one portion of the housing has a diameter of at most 1 mm.

2. The apparatus according to claim 1, wherein the dispersive arrangement contains at least one of a diffractive element or a refractive element.

3. The apparatus according to claim 2, wherein the element grating is at least one of a fiber grating, a blazed grating, a binary, or a holographic lens grating.

4. The apparatus according to claim 1, wherein the at least one lens contains at least one of a gradient index lens, a reflective mirror lens grating combination or a diffractive lens.

5. The apparatus according to claim 1, wherein the optical waveguide is an optical fiber.

6. The apparatus according to claim 5, wherein the optical fiber is positioned in the apparatus such that an end portion thereof is provided at a position of an image plane of the at least one section of the structure which is established by the at least one lens.

7. The apparatus according to claim 1, wherein the at least one of the two-dimensional image or the three-dimensional image contains from about 300,000 to 1,000,000 resolvable points.

8. The apparatus according to claim 1, wherein the at least one of the two-dimensional image or the three-dimensional image contains from about 150,000 to 300,000 resolvable points.

9. The apparatus according to claim 1, wherein the at least one of the two-dimensional image or the three-dimensional image contains from about 100,000 to 150,000 resolvable points.

10. The apparatus according to claim 1, wherein the diameter of the at least one portion is of less than 1.0 mm.

11. The apparatus according to claim 1, further comprising an additional structural arrangement configured to modify at least one property of the structure.

12. The apparatus according to claim 11, wherein the additional arrangement is at least one of an ultrasonic arrangement, a laser arrangement, a cauterizing tip, a set of retractable teeth forming a claw for grabbing an object, a suction tube or an arrangement including a mechanical grasper for grasping a sample.

13. The apparatus according to claim 1, wherein the optical waveguide comprises a plurality of fibers each of which is configured to provide there through the electro-magnetic radiation, at least one first fiber of the fibers being configured to provide a first electro-magnetic radiation to the at least one section so as to obtain the information, and at least one second fiber of the fibers configured to provide a second electro-magnetic radiation to the at least one section so as to modify at least one property of the structure.

14. The apparatus according to claim 13, wherein the first and second fibers are polished at different angles from one another.

15. The apparatus according to claim 1, wherein the grating is further configured to the at least one section to be at least partially overlapped with a plurality of electro-magnetic radiations, wherein one of the electro-magnetic radiations has a wavelength in a first range, and another one of the electro-magnetic radiations has a wavelength in a second range, and wherein each of the first and second ranges are at least one element that is different from another one of the second ranges.

16. The apparatus according to claim 1, wherein at least one of a property, an orientation or a position of the dispersive grating arrangement is capable of being modified to provide a further radiation to a particular location of the at least one section, and wherein the at least one property of the dispersed radiation is capable of being different from a property of the further radiation.

17. The apparatus according to claim 1, wherein the at least one lens and the grating are sized so as to be encompassed within a needle having a gauge of about 20 or smaller.

18. The apparatus according to claim 1, further comprising a processing arrangement which receives data associated with the dispersed radiation provided to the at least one section of the structure, and generates a single image based on the data and as a function of a plurality of wavelengths of the electro-magnetic radiation.

19. The apparatus according to claim 1, further comprising a detection arrangement which is configured to detect a further radiation provided from the structure.

20. The apparatus according to claim 19, wherein the dispersive arrangement is provided closer to the structure than the detection arrangement.

21. The apparatus according to claim 1, further comprising a detection arrangement which is configured to detect a further radiation provided from the structure.

22. The apparatus according to claim 1, wherein the electro-magnetic radiation is provided through the optical waveguide to impact (i) at least one of the at least one lens or the dispersive grating arrangement, (ii) then another one of the at least one lens or the grating, and (iii) then the anatomical structure.

23. The apparatus according to claim 1, wherein the radiation is provided from the anatomical structure to impact (i) at least one of the at least one lens or the dispersive grating arrangement, and (ii) then another one of the at least one lens or the grating.

24. The apparatus according to claim 1, wherein the lens is provided in the housing.

25. The apparatus according to claim 1, wherein the at least one portion of the housing is dimensioned to be provided in vivo.

26. The apparatus according to claim 1, wherein the optical waveguide is a single mode fiber.

27. An apparatus for obtaining diagnostic information associated with an anatomical structure and modifying at least one property of at least one portion of the structure, comprising:

a housing;

at least one lens that is different from the housing;

an optical waveguide configured to transmit and receive an electro-magnetic radiation from the structure, and including a plurality of fibers which are configured to provide there through the electro-magnetic radiation, at least one first fiber of the fibers being configured to provide a first electro-magnetic radiation to the at least one portion so as to obtain the information, and at least one second fiber of the fibers configured to provide a second electro-magnetic radiation to the at least one section of the structure regarding which the information is being obtained so as to modify the at least one property, wherein the electro-magnetic radiation is provided by at least one of a broadband source or a wavelength tuned source;

at least one further arrangement including a computer which is structured to obtain the information based on a radiation obtained from the structure, wherein the information is at least one of a two-dimensional image or a three dimensional image; and

a dispersive arrangement including a grating configured to receive the first and second electromagnetic radiations and forward a dispersed radiation thereof to the at least one section of the structure, wherein the grating has a groove density that is at least 1200 lines/mm, wherein the at least one lens and the dispersive arrangement are provided in at least one portion of the housing and in an optical path between the optical waveguide and a location of the apparatus at which the electro-magnetic radiation is received from the anatomical structure, and wherein the at least one portion of the housing has a diameter of at most 1 mm.

28. The apparatus according to claim 27, wherein the electro-magnetic radiation is provided by at least one of a broadband source or a wavelength tuned source.

29. The apparatus according to claim 27, wherein the dispersive arrangement contains at least one of a diffractive grating element or a refractive element.

30. The apparatus according to claim 29, wherein the grating is at least one of a fiber grating, a blazed grating, a binary, or a holographic lens grating.

31. The apparatus according to claim 27, wherein the lens contains at least one of a gradient index lens, a reflective mirror lens grating combination or a diffractive lens.

32. The apparatus according to claim 27, wherein the at least one of the two-dimensional image or the three-dimensional image contains from about 300,000 to 1,000,000 resolvable points.

33. The apparatus according to claim 27, wherein the at least one of the two-dimensional image or the three-dimensional image contains from about 150,000 to 300,000 resolvable points.

34. The apparatus according to claim 27, wherein the at least one of the two-dimensional image or the three-dimensional image contains from about 100,000 to 150,000 resolvable points.

35. The apparatus according to claim 27, wherein the at least one portion of the housing has a diameter of less than 1.0 mm.

36. The apparatus according to claim 27, further comprising an additional structural arrangement configured to modify at least one property of the structure.

37. The apparatus according to claim 36, wherein the additional arrangement is at least one of an ultrasonic arrangement, a laser arrangement, a cauterizing tip, a set of retractable teeth forming a claw for grabbing an object, a suction tube or an arrangement including a mechanical grasper for grasping a sample.

38. The apparatus according to claim 27, wherein at least one first fiber of the fibers is configured to provide a first electro-magnetic radiation to the at least one portion so as to obtain the information, and at least one second fiber of the fibers is configured to provide a second electro-magnetic radiation to the at least one portion so as to modify at least one property of the structure.

39. The apparatus according to claim 27, wherein the dispersive arrangement is further configured to cause the at least one portion to be at least partially overlapped with a plurality of electro-magnetic radiations, wherein one of the electro-magnetic radiations has a wavelength in a first range, and another one of the electro-magnetic radiations has a wavelength in a second range, and wherein each of the first and second ranges are at least one element that is different from another one of the second ranges.

40. The apparatus according to claim 39, wherein the first and second electro-magnetic radiations overlap one another at the at least one portion.

41. The apparatus according to claim 27, wherein at least one of a property, an orientation or a position of the dispersive grating arrangement is capable of being modified to provide a further radiation to a particular location of the at least one portion, and wherein the at least one property of the dispersed radiation is capable of being different from a property of the further radiation.

42. The apparatus according to claim 27, wherein the at least one lens and the grating are sized so as to be encompassed within a needle having a gauge of about 20 or smaller.

43. The apparatus according to claim 27, wherein the grating is further configured to forward a dispersed radiation thereof to at least one portion of the structure on a macroscopic scale.

44. The apparatus according to claim 27, further comprising a plurality of probes, each of the probes capable of providing spatially encoded location information associated with the at least one portion.

45. The apparatus according to claim 27, wherein the dispersive arrangement includes at least one of a fiber grating, a blazed grating, a binary, a or a holographic lens grating.

46. The apparatus according to claim 45, further comprising a further grating which follows the dispersive grating arrangement and provided in a path of the electro-magnetic radiation.

47. An apparatus for obtaining information associated with an anatomical structure, comprising:

a housing;

at least one lens that is different from the housing, and which is configured to provide a plurality of electro-magnetic radiations, and a dispersive arrangement including a grating configured to receive the electro-magnetic radiations and forward a dispersed radiation of each of the electro-magnetic radiations to at least one section of the structure regarding which the information is being obtained and at least partially overlap the at least one portion, wherein one of the electro-magnetic radiations has a wavelength in a first range, and another one of the electro-magnetic radiations has a wavelength in a second range, and wherein each of the first and second ranges are at least one element that is different from another one of the second ranges, wherein the electro-magnetic radiations are provided by at least one of a broadband source or a wavelength tuned source;

an optical waveguide configured to transmit and receive the electro-magnetic radiation to and from the structure; and

at least one further arrangement including a computer which is structured to obtain the information based on a radiation obtained from the structure, wherein the information is at least one of a two-dimensional image or a three dimensional image, wherein the grating has a groove density that is at least 1200 lines/mm, wherein the at least one lens and the dispersive arrangement are provided within at least one portion of the housing and in an optical path between the optical waveguide and a location of the apparatus at which the electro-magnetic radiation is received from the anatomical structure, and wherein the at least one portion of the housing has a diameter of at most 1 mm.

48. The apparatus according to claim 47, wherein the optical waveguide comprises a plurality of optical fibers, wherein at least one first fiber of the fibers is configured to provide a first electro-magnetic radiation to the at least one portion so as to obtain the information, and at least one second fiber of the fibers is configured to provide a second electro-magnetic radiation to the at least one portion so as to modify at least one property of the structure.

49. The apparatus according to claim 47, wherein the optical waveguide comprises a plurality of fibers each of which is configured to provide there through the electro-magnetic radiation, at least one first fiber of the fibers being configured to provide a first electro-magnetic radiation to the at least one portion so as to obtain the information, and at least one second fiber of the fibers configured to provide a second electro-magnetic radiation to the at least one portion so as to modify at least one property of the structure.

50. The apparatus according to claim 47, wherein at least one of a property, an orientation or a position of the dispersive grating arrangement is capable of being modified to provide a further radiation to a particular location of the at least one portion, and wherein the at least one property of the dispersed radiation is capable of being different from a property of the further radiation.

51. The apparatus according to claim 47, wherein the at least one lens and the grating are sized so as to be encompassed within a needle having a gauge of about 20 or smaller.

52. The apparatus according to claim 47, wherein the grating includes at least one of a fiber grating, a blazed grating, a binary, a or a holographic lens grating.

53. The apparatus according to claim 52, further comprising a further grating which follows the dispersive arrangement and provided in a path of the electro-magnetic radiation.

54. The apparatus according to claim 47, wherein the optical waveguide comprises a plurality of fibers each of which is configured to provide there through the electro-magnetic radiations.

55. The apparatus according to claim 54, wherein the electro-magnetic radiations provided from the structure are associated with the information.

56. The apparatus according to claim 55, wherein the information is at least one of a color, a multispectral dataset or a hyperspectral dataset.

57. The apparatus according to claim 56, wherein the at least one of the multispectral dataset or the hyperspectral dataset is at least one of a two-dimensional image, a three-dimensional image or a four-dimensional image.

58. The apparatus according to claim 47, further comprising a detection arrangement which is configured to detect a further radiation provided from the structure.

59. The apparatus according to claim 58, wherein the dispersive arrangement is provided closer to the structure than the detection arrangement.

60. An apparatus for obtaining information associated with an anatomical structure, comprising:

a housing;

at least one lens that is different from the housing, and which is configured to provide an electro-magnetic radiation, wherein the electro-magnetic radiation is provided by at least one of a broadband source or a wavelength tuned source;

a dispersive arrangement including a grating configured to receive at least one portion of the electro-magnetic radiation and forward a dispersed radiation thereof to a particular location on at least one section of the structure regarding which the information is being obtained;

an optical waveguide configured to transmit and receive the electro-magnetic radiation to and from the structure; and

at least one further arrangement including a computer which is structured to obtain the information based on a radiation obtained from the structure, wherein the information is at least one of a two-dimensional image or a three dimensional image,

wherein at least one of a property, an orientation or a position of the dispersive grating arrangement is capable of being modified to provide a further radiation to the particular location of the at least one section, and wherein at least one property of the dispersed radiation is capable of being different from a property of the further radiation, wherein the grating has a groove density that is at least 1200 lines/mm, wherein the at least one lens and the dispersive arrangement are provided within at least one portion of the housing and in an optical path between the optical waveguide and a location of the apparatus at which the electro-magnetic radiation is received from the anatomical structure, and wherein the at least one portion of the housing has a diameter of at most 1 mm.

61. The apparatus according to claim 60, wherein the optical waveguide comprises a plurality of optical fibers, wherein at least one first fiber of the fibers is configured to provide a first electro-magnetic radiation to the at least one portion so as to obtain the information, and at least one second fiber of the fibers is configured to provide a second electro-magnetic radiation to the at least one portion so as to modify at least one property of the structure.

62. The apparatus according to claim 60, wherein the optical waveguide comprises a plurality of fibers each of which is configured to provide there through the electro-magnetic radiation, at least one first fiber of the fibers being configured to provide a first electro-magnetic radiation to the at least one portion so as to obtain the information, and at least one second fiber of the fibers configured to provide a second electro-magnetic radiation to the at least one portion so as to modify at least one property of the structure.

63. The apparatus according to claim 60, wherein the dispersive arrangement is further configured to cause the at least one portion to be at least partially overlapped with a plurality of electro-magnetic radiations, wherein one of the electro-magnetic radiations has a wavelength in a first range, and another one of the electro-magnetic radiations has a wavelength in a second range, and wherein each of the first and second ranges are at least one element that is different from another one of the second ranges.

64. The apparatus according to claim 60, wherein the at least one lens and the grating are sized so as to be encompassed within a needle having a gauge of about 20 or smaller.

65. The apparatus according to claim 60, wherein the grating is further configured to forward the dispersed radiation thereof to at least one portion of the structure on a macroscopic scale.

66. The apparatus according to claim 60, further comprising a detection arrangement which is configured to detect a further radiation provided from the structure.

67. The apparatus according to claim 66, wherein the dispersive arrangement is provided closer to the structure than the detection arrangement.

68. An apparatus for obtaining information associated with an anatomical structure, comprising:

a housing;

at least one lens that is different from the housing, and which is configured to provide there through electro-magnetic radiation, wherein the electro-magnetic radiation is provided by at least one of a broadband source or a wavelength tuned source;

an optical waveguide including a single mode fiber which is configured and designed to transmit the electro-magnetic radiation to and from the structure;

at least one further arrangement including a computer which is structured to obtain the information based on a radiation obtained from the structure, wherein the information is at least one of a two-dimensional image or a three dimensional image; and

a dispersive arrangement including a grating which is configured to receive at least one portion of the electro-magnetic radiation and forward a dispersed radiation thereof to at least one section of the structure regarding which the information is being obtained, wherein the lens and dispersive arrangements are sized so as to be encompassed within a needle having a gauge of about 20 or smaller, wherein the grating has a groove density that is at least 1200 lines/mm, wherein the at least one lens and the dispersive arrangement are provided within at least one portion of the housing and in an optical path between the single mode fiber and a location of the apparatus at which the electro-magnetic radiation is received from the anatomical structure.

69. The apparatus according to claim 68, wherein the optical waveguide comprises a plurality of optical fibers, wherein at least one first fiber of the fibers is configured to provide a first electro-magnetic radiation to the at least one portion so as to obtain the information, and at least one second fiber of the fibers is configured to provide a second electro-magnetic radiation to the at least one portion so as to modify at least one property of the structure.

70. The apparatus according to claim 68, wherein the optical waveguide comprises a plurality of fibers each of which is configured to provide there through the electro-magnetic radiation, at least one first fiber of the fibers being configured to provide a first electro-magnetic radiation to the at least one portion so as to obtain the information, and at least one second fiber of the fibers configured to provide a second electro-magnetic radiation to the at least one portion so as to modify at least one property of the structure.

71. The apparatus according to claim 68, wherein the dispersive arrangement is further configured to cause the at least one portion to be at least partially overlapped with a plurality of electro-magnetic radiations, wherein one of the electro-magnetic radiations has a wavelength in a first range, and another one of the electro-magnetic radiations has a wavelength in a second range, and wherein each of the first and second ranges are at least one element that is different from another one of the second ranges.

72. The apparatus according to claim 68, wherein at least one of a property, an orientation or a position of the dispersive grating arrangement is capable of being modified to provide a further radiation to a particular location of the at least one portion, and wherein the at least one property of the dispersed radiation is capable of being different from a property of the further radiation.

73. The apparatus according to claim 68, wherein the dispersive arrangement is further configured to forward the dispersed radiation thereof to at least one portion of the structure on a macroscopic scale.

74. The apparatus according to claim 68, further comprising a detection arrangement which is configured to detect a further radiation provided from the structure.

75. The apparatus according to claim 74, wherein the dispersive grating arrangement is provided closer to the structure than the detection arrangement.

76. An apparatus for obtaining information associated with a structure, comprising:

a lens arrangement which is configured to provide there through an electro-magnetic radiation; and

a dispersive arrangement including a light dispersive element which is configured to receive at least one portion of the electro-magnetic radiation and forward a dispersed radiation thereof to at least one section of the structure regarding which the information is being obtained, wherein the light dispersive element has a groove density that is at least 1200 lines/mm without a controlled mechanical motion, and wherein the lens arrangement and the dispersive arrangement are provided in a structure that has a diameter of at most 1 mm.

77. An apparatus for obtaining diagnostic information associated with a structure and modifying at least one property of at least one portion of the structure, comprising:

a lens arrangement and a plurality of fibers which are configured to provide there through the electro-magnetic radiation, at least one first fiber of the fibers being configured to provide a first electro-magnetic radiation to the at least one portion so as to obtain the information, and at least one second fiber of the fibers configured to provide a second electro-magnetic radiation to the at least one portion of the structure regarding which the information is being obtained so as to modify the at least one property; and

a dispersive arrangement including a light dispersive element configured to receive the first and second electromagnetic radiations and forward a dispersed radiation thereof to at least one section of the structure regarding which the information is being obtained, wherein the light dispersive element has a groove density that is at least 1200 lines/mm, and wherein the lens arrangement and the light dispersive element are provided in a structure that has a diameter of at most 1 mm.

78. An apparatus for obtaining information associated with a structure, comprising:

a lens arrangement which is configured to provide a plurality of electro-magnetic radiations and a dispersive arrangement including a light dispersive element configured to receive the electro-magnetic radiations and forward a dispersed radiation of each of the electro-magnetic radiations to at least one portion of the structure regarding which the information is being obtained, and at least partially overlap the at least one portion, wherein one of the electro-magnetic radiations has a wavelength in a first range, and another one of the electro-magnetic radiations has a wavelength in a second range, wherein each of the first and second ranges are at least one element that is different from another one of the second ranges, wherein the light dispersive element has a groove density that is at least 1200 lines/mm, and wherein the lens arrangement and the dispersive arrangement are provided in a structure that has a diameter of at most 1 mm.

79. An apparatus for obtaining information associated with a structure, comprising:

a lens arrangement which is configured to provide an electro-magnetic radiation; and

a dispersive arrangement including a light dispersive element configured to receive at least one portion of the electro-magnetic radiation and forward a dispersed radiation thereof to a particular location on at least one portion of the structure regarding which the information is being obtained,

wherein at least one of a property, an orientation or a position of the dispersive arrangement is capable of being modified to provide a further radiation to the particular location of the at least one portion, wherein at least one property of the dispersed radiation is capable of being different from a property of the further radiation, and wherein the light dispersive element has a groove density that is at least 1200 lines/mm, and wherein the lens arrangement and the dispersive arrangement are provided in a structure that has a diameter of at most 1 mm.

80. An apparatus for obtaining information associated with a structure, comprising:

a lens arrangement which is configured to provide there through electro-magnetic radiation; and

a dispersive arrangement including a light dispersive element which is configured to receive at least one portion of the electro-magnetic radiation and forward a dispersed radiation thereof to at least one portion of the structure regarding which the information is being obtained, wherein the light dispersive element has a groove density that is at least 1200 lines/mm in a field size of below about 1 mm², and wherein the lens arrangement and the dispersive arrangement are provided in a structure that has a diameter of at most 1 mm.

81. An apparatus for obtaining information associated with a structure, comprising:

a lens arrangement which is configured to provide there through an electro-magnetic radiation; and

a dispersive arrangement including a light dispersive element which is configured to receive at least one portion of the electro-magnetic radiation and forward a dispersed radiation thereof to at least one section of the structure regarding which the information is being obtained, wherein the light dispersive element has a groove density that is at least 1200 lines/mm, and wherein the lens arrangement and the dispersive arrangement are provided in a structure that has a diameter of at most 1 mm.