Transform lens with a plurality of sliced lens segments

• US 5,189,294 A
• Filed: 07/08/1992
• Issued: 02/23/1993
• Est. Priority Date: 07/08/1992
• Status: Expired due to Fees

• Current Assignee: Unites States Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Jackson, John E., Leung, Christopher C., Levy, Joseph L., Burkhart, Gordon H.
• Primary Examiner(s): Nelms, David C.
• Assistant Examiner(s): LE, QUE TAN
• Application Number:
  US07/910,466
• Time in Patent Office: 230 Days
• Field of Search: 250/201.9, 250/201.2, 250/208.2, 250/216, 356/121, 356/359, 356/353, 359/721, 359/724, 359/742, 359/743, 359/708, 359/900
• US Class Current: 250/201.9
• CPC Class Codes: G02B 3/00 Simple or compound lenses
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence

Abstract

A sliced transform lens is used to combine and focus the optical output signals of a planar M by N laser diode array onto M detector elements in a linear detector by displacing lens slices. A sliced transform lens is used to separate the composite image of the laser diode array on the detector plane into ten spots (400 emitters per spot) by displacing the lens slices relative to each other collimated He-Ne laser beam was used to examine the sliced transform lens and the linear detector array was used to measure the image sizes and the crosstalks between the images. The results show the minimum separation is approximately five detector spacings apart. The lens elements are cut from a bulk material (BK-7) and ground to desired thickness and parallelism. Then the elements are "glued" together with standard optical wax compound and ground to the prescribed focal length. THe lens slices are cut before grinding, hence the composite lens is symmetric and zero-curf configuration is preserved. This relaxes the collimation requirement of the incoming light to some extent. The lens is then polished and ready for application.

Claims

1. A transform lens for use with a planar array of light emitting elements, wherein said planar array includes N rows and M columns of light emitting elements, which each output of an optical output signal, wherein N and M are integers, wherein said transform lens comprises:

a plurality of sliced lens segments, each of which is aligned to capture and focus the optical output signals of a single column of light emitting elements, and outputting thereby M rows of focused optical signal spots, wherein each focused optical signal spot contains the optical output signals of a N light emitting elements in a particular column; and

a means for holding said plurality of sliced lens segments in place to collectively form said transform lens thereby.

2. A transform lens, as defined in claim 1, wherein said holding means comprises a plurality of layers of optical cement which are interleaved between adjacent sliced lens segments to hold them in place.

3. A transform lens, as defined in claim 1 which focuses the optical output signals of said planar array onto a linear detector array of M detector elements, wherein each sliced lens segment combines and focuses all of the output signals of the light emitting elements of a single column of said planar array onto one of the M detector elements.

4. A transform lens, as defined in claim 2 which focuses the optical output signals of said planar array onto a linear detector array of M detector elements, wherein each sliced lens segment combines and focuses all of the output signals of the light emitting elements of a single column of said planar array onto one of the M detector elements.

5. A transform lens, as defined in claim 3, wherein each detector element has a width of value W, and wherein each detector element is separated from an adjacent detector element by integral multiples of W.

6. A transform lens, as defined in claim 4, wherein each detector element has a width of value W, and wherein each detector element is separated from an adjacent detector element by integral multiples of W.

7. A transform process for use with a planar array of light emitting elements, wherein said planar array includes N rows and M columns of light emitting elements, which each output an optical output signal, wherein N and M are integers, wherein said transform process comprises:

combining the optical output signals of all of the rows of light emitting elements in each column of the planar array to produce thereby M combined optical signals; and

focusing the M combined optical signals onto a linear array of detector elements to enable characteristics said planar array of light emitting elements to be measured by M detector elements.

8. A process, as defined in claim 7, wherein said focusing step is performed by a plurality of sliced lens segments, each of which is aligned to capture and focus the optical output signals of a single column of light emitting elements, and outputting thereby M rows of focused optical signal spots, wherein each focused optical signal spot contains the optical output signals of a N light emitting elements in a particular column.

9. A transform lens system for use with a planar array of light emitting elements, wherein said planar array includes N rows and M columns of light emitting elements, which each output an optical output signal, wherein N and M are integers, wherein said transform lens system comprises:

a means for extracting a sample of the optical output signals of said planar array of light emittinq elements to produce thereby samples of the optical output signals;

a plurality of sliced lens segments, each of which is aligned to capture and focus the samples of the optical output signals of a single column of light emitting elements, and outputting thereby M rows of focused optical signal spots, wherein each focused optical signal spot contains the optical output signals of a N light emitting elements in a particular column; and

a means for measuring the optical signal spots produced by said sliced lens segments to determine thereby characteristics of the optical output signals of planar array of light emitting elements.

10. A transform lens system, as defined in claim 9, wherein said measuring means comprises:

a linear array of M detector elements which intercept and electrooptically convert the M optical signal spots into M analog electrical signals;

A/D converter elements which convert said analog electrical signals into digital electrical signals; and

a computer which receives and measures the digital electrical signals from the A/D converter elements.

11. A transform lens system, as defined in claim 9, wherein said extracting means comprises a beam splitter, which intercepts and splits the optical output signals of the planar array of light emitting elements to produce thereby the samples of optical output signals for the plurality of sliced lens segments.

12. A transform lens system, as defined in claim 10, wherein said extracting means comprises a beam splitter, which intercepts and splits the optical output signals of the planar array of light emitting elements to produce thereby the samples of optical output signals for the plurality of sliced lens segments.

13. A transform lens system, as defined in claim 9, including a means for holding said plurality of sliced lens segments in place to collectively form a transform lens thereby.

14. A transform lens system, as defined in claim 10, including a means for holding said plurality of sliced lens segments in place to collectively form a transform lens thereby.

15. A transform lens system, as defined in claim 11, including a means for holding said plurality of sliced lens segments in place to collectively form a transform lens thereby.

16. A transform lens system, as defined in claim 12, including a means for holding said plurality of sliced lens segments in place to collectively form a transform lens thereby.