System for producing uniform illumination for testing two dimensional detector arrays and optical systems

• US 6,191,891 B1
• Filed: 10/05/1998
• Issued: 02/20/2001
• Est. Priority Date: 10/05/1998
• Status: Expired due to Fees

• Current Assignee: Sylvia Y. Kan
• Original Assignee: Sylvia Y. Kan
• Inventors: Pellicori, Samuel F.
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): BOUTSIKARIS, LEONIDAS
• Application Number:
  US09/167,043
• Time in Patent Office: 869 Days
• Field of Search: 362/268, 362/293, 362/282, 362/284, 362/322, 362/323, 362/324, 362/301, 359/599, 359/503, 359/364, 356/371
• US Class Current: 359/599
• CPC Class Codes: G01J 1/08 Arrangements of light sources specially adapted for photometry standard sources, also using luminescent or radioactive material
• CPC Class Codes: G01J 2001/083 Testing response of detector
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0944 Diffractive optical elements, e.g. gratings, holograms gratings per se G02B5/18; holograms used as optical elements per se G02B5/32
• CPC Class Codes: G02B 5/0252 using holographic or diffractive means

Abstract

A compact, efficient illumination system has many advantages over conventional illuminators based upon integrating spheres. An elliptical light source/concentrator, preferably controlled by a light stabilization system using optical feedback to control the light intensity, provides high spatial uniformity of high irradiance values can be produced over sizeable areas for testing large area detector arrays. The illuminator is simpler and more economical than traditional systems and provides extended wavelength coverage potential. The illumination system is easy to maintain.

Claims

1. An illuminator system for producing light having high spatial uniformity comprising;

an ellipsoidal reflector having a first focal point;

a lamp located at said first focal point with respect to said ellipsoidal reflector, said ellipsoidal reflector and said lamp for producing light output in a first direction;

an aspheric field lens in optical alignment with at least one of said ellipsoidal reflector and said lamp for receiving and transmitting light propagating in said first direction from said ellipsoidal reflector and said lamp;

a diffuser in optical alignment with at least one of said ellipsoidal reflector and said lamp for receiving and transmitting light propagating in said first direction from said ellipsoidal reflector and said lamp;

an achromatic lens in optical alignment with said at least one of said ellipsoidal reflector and said lamp for receiving light propagating in said first direction from said ellipsoidal reflector and said lamp, said transmitted light having high spatial uniformity; and

a meniscus lens in optical alignment with one of said lamp and said ellipsoidal reflector.

2. The illuminator system as recited in claim 1 wherein said diffuser is a holographic diffuser.

3. The illuminator system as recited in claim 2 and further comprising a plurality of said holographic diffusers.

4. The illuminator system as recited in claim 1 and further comprising a heat rejecting filter interposed between said lamp and one of said aspheric field lens and said diffuser, said heat rejecting filter in optical alignment with both said lamp and said one of said aspheric field lens and said diffuser.

5. The illuminator system as recited in claim 1 and further comprising a spectral filter in optical alignment with one of said lamp and said ellipsoidal reflector.

6. The illuminator system as recited in claim 1 and wherein the spatial order of alignment is, after said ellipsoidal reflector and said lamp, said aspheric field lens, said diffuser and said achromatic lens.

14. The illuminator system as recited in claim 1 and further comprising a power control electrically connected to said lamp and having a detector in optical communication with said lamp and electrically connected to said power control.

7. An illuminator system for producing light having high spatial uniformity comprising:

an ellipsoidal reflector having a first focal point;

a lamp located at said first focal point with respect to said ellipsoidal reflector, said ellipsoidal reflector and said lamp for producing light output in a first direction;

an aspheric field lens in optical alignment with at least one of said ellipsoidal reflector and said lamp for receiving and transmitting light propagating in said first direction from said ellipsoidal reflector and said lamp;

a diffuser in optical alignment with at least one of said ellipsoidal reflector and said lamp for receiving and transmitting light propagating in said first direction from said ellipsoidal reflector and said lamp;

an achromatic lens in optical alignment with said at least one of said ellipsoidal reflector and said lamp for receiving light propagating in said first direction from said ellipsoidal reflector and said lamp, said transmitted light having high spatial uniformity; and

a meniscus lens between said aspheric field lens and said achromatic lens.

8. The illuminator system as recited in claim 7 and further comprising a power control electrically connected to said lamp and having a detector in optical communication with said lamp and electrically connected to said power control.

9. An illuminator system for producing light having high spatial uniformity comprising:

an ellipsoidal reflector having a first focal point;

a lamp located at said first focal point with respect to said ellipsoidal reflector, said ellipsoidal reflector and said lamp for producing light output in a first direction;

an aspheric field lens in optical alignment with at least one of said ellipsoidal reflector and said lamp for receiving and transmitting light propagating in said first direction from said ellipsoidal reflector and said lamp;

a field homogenizer in optical alignment with at least one of said ellipsoidal reflector and said lamp for receiving and transmitting light propagating in said first direction from said ellipsoidal reflector and said lamp; and

wherein said field homogenizer further comprises;

a first diffuser in optical alignment between said ellipsoidal reflector and said aspheric field lens;

a second diffuser, said aspheric field lens in optical alignment between said first and said second diffuser;

a first neutral density filter wheel optical alignment with said second diffuser;

a shutter in optical alignment with said first neutral density filter;

a second neutral density filter wheel in optical alignment with said shutter and also in optical alignment with said achromatic lens;

an achromatic lens in optical alignment with said at least one of said ellipsoidal reflector and said lamp for receiving light propagating in said first direction from said ellipsoidal reflector and said lamp, said transmitted light having high spatial uniformity.

10. The illuminator system as recited in claim 9 wherein said first and second diffusers are holographic diffusers.

11. The illuminator system as recited in claim 9 and further comprising a filter wheel in optical alignment between said shutter and said second neutral density filter wheel.

12. The illuminator system as recited in claim 11 wherein said filter wheel is a bandpass filter wheel.

13. An illuminator system for producing light having high spatial uniformity comprising:

an ellipsoidal reflector having a first focal point;

a lamp located at said first focal point with respect to said ellipsoidal reflector, said ellipsoidal reflector and said lamp for producing light output in a first direction;

an aspheric field lens in optical alignment with at least one of said ellipsoidal reflector and said lamp for receiving and transmitting light propagating in said first direction from said ellipsoidal reflector and said lamp;

a field homogenizer in optical alignment with at least one of said ellipsoidal reflector and said lamp for receiving and transmitting light propagating in said first direction from said ellipsoidal reflector and said lamp;

an achromatic lens in optical alignment with said at least one of said ellipsoidal reflector and said lamp for receiving light propagating in said first direction from said ellipsoidal reflector and said lamp, said transmitted light having high spatial uniformity; and

a meniscus lens in optical alignment between said field homogenizer and said aspheric lens.

15. The illuminator system as recited in claim 13 and further comprising a power control electrically connected to said lamp and having a detector in optical communication with said lamp and electrically connected to said power control.