Method and apparatus for creating transient optical elements and circuits

• US 5,126,874 A
• Filed: 07/11/1990
• Issued: 06/30/1992
• Est. Priority Date: 07/11/1990
• Status: Expired due to Term

• Current Assignee: City College of New York
• Original Assignee: Li Yao, P. L. Baldeck, Robert R. Alfano
• Inventors: Li, Yao, Baldeck, P. L., Alfano, Robert R.
• Primary Examiner(s): LaRoche, Eugene R.
• Assistant Examiner(s): Lester, Evelyn A.
• Application Number:
  US07/552,677
• Time in Patent Office: 720 Days
• Field of Search: 350/354, 350/163, 359/240, 359/241, 359/244
• US Class Current: 359/240
• CPC Class Codes: G02F 1/3511 Self-focusing or self-trapping of light; Light-induced birefringence; Induced optical Kerr-effect
• CPC Class Codes: G02F 1/3515 All-optical modulation, gating, switching, e.g. control of a light beam by another light beam G02F1/353, G02F1/37, G02F1/39 take precedence

Abstract

A transient optical element is created by providing a body of a third order non-linear material and then passing a pulse of light through the body of non-linear material. The pulse of light has a cross-sectional area corresponding to the cross-sectional area of the transient optical element to be created and power sufficient to induce an index of refraction change over the portion of the body of non-linear material through which it passes. The portion of the body of non-linear material having the induced index of refraction change constitutes the transient optical element with the duration of the transient optical element depending on the response time of the non-linear material and the duration of pulse of light. Typical optical elements that can be so created include prisms, lenses, gratings, mirrors, beamsplitters and wave guides. By forming a plurality of optical elements within the third order non-linear material rather than simply a single optical element, a transient optical circuit can be created.

Claims

1. A method of creating a transient optical element comprising:

a) providing a body of a nonlinear material, and

b) passing an area modulated beam of light of uniform intensity through the body of nonlinear material, the area modulated beam of light having a cross-sectional area corresponding to the cross-sectional area of the transient optical element to be created, the area modulated beam of light having power sufficient to induce an index of refraction change over the portion of the body of nonlinear material through which the beam of light passes, the portion of the body of nonlinear material having the induced index of refraction change constituting the transient optical element, the duration of the transient optical element depending on the response time of the nonlinear material and the duration of the area modulated beam of light.

2. Apparatus for creating a transient optical element comprising:

a) means for producing an area modulated beam of light of uniform intensity, and

b) a body of a nonlinear material disposed along the path of said area modulated beam of light,

c) said area modulated beam of light having a cross-sectional area corresponding to the cross-sectional area of the transient optical element to be created, said area modulated beam of light having power sufficient to induce an index of refraction change over the portion of the body of nonlinear material through which the are modulated beam of light passes, the portion of the body of nonlinear material having the induced index of refraction change constituting the transient optical element, the duration of the transient optical element depending on the response time of the nonlinear material and the duration of the area modulated beam of light.

3. The apparatus of claim 2 and wherein the cross-sectional area of the area modulated beam of light is in the shape of a triangle for use in inducing the creation of a prism or a beamsplitter.

4. The apparatus of claim 2 and wherein the cross-sectional area of the area modulated beam of light is in the shape of an ellipse for use in inducing the creation of a lens.

5. The apparatus of claim 2 and wherein the cross-sectional area of the area modulated beam of light is in the shape of a plurality of steps for use in inducing the creation of a grating.

6. The apparatus of claim 2 and wherein the cross-sectional area of the area modulated beam of light is in the shape of a one or more rectangules for use in inducing the creation of a waveguide.

7. The apparatus of claim 2 and wherein the cross-sectional area of the area modulated beam of light is in the shape of a circle.

8. The apparatus of claim 2 and wherein the means for producing an area modulated beam of light includes a light source for generating a beam of light and a mask for masking off a portion of said beam of light.

9. The apparatus of claim 8 and further including a beam expander for expanding the light beams.

10. The apparatus of claim 8 and wherein the light source comprises a mode locked YAG laser or a semiconductor laser or a Q-switched laser.

11. The apparatus of claim 2 and wherein the nonlinear material is a third order nonlinear material.

12. The apparatus of claim 2 and wherein the means for producing an area modulated beam of light comprises a light source for producing a beam of light and a mask disposed for area modulating said beam of light.

13. Apparatus for creating a transient optical element comprising:

a) a body of a nonlinear material,

b) means for illuminating the body with a beam of light, and

c) a mask for masking the beam of light before it strikes the body, the mask having a cross-sectional area corresponding to the cross-sectional area of the transient optical element to be created, the beam of light having power sufficient to induce an index of refraction change over the portion of the body of nonlinear material through which the beam passes, the portion of the body of nonlinear material having the induced index of refraction change constituting the transient optical element, the duration of the transient optical element depending on the nonlinear material and the beam of light.

14. A method of creating a transient optical circuit, the transient optical circuit comprising a plurality of transient optical elements, the method comprising:

a. providing a body of a nonlinear material, and

b. passing a plurality of beams of light through the body of nonlinear material, each through a different portion, each one of the beams of light having a cross-sectional area corresponding to the cross-sectional area of one of the transient optical elements to be created, each one of the beams of light having power sufficient to induce an index of refraction change over the portion of the body of nonlinear material through which the beam passes, the portion of the body of nonlinear material having the induced index of refraction change constituting the transient optical element with the duration of the transient optical element depending on the nonlinear material and the particular beam of light.

15. Apparatus for creating a transient optical circuit comprising:

a. means for producing a beam of light,

b. a body of nonlinear material disposed along the path of the beam of light, and

c. a mask disposed along the path of the beam of light in front of the body of nonlinear material for area modulating the beam of light, the mask having a plurality of discrete shapes, each corresponding to the cross-section of an optical element to be created.

16. The apparatus of claim 15 and further including a spatial filter for making the beam uniform in intensity.