Grating-enhanced optical imaging
Systems, methods and devices are implemented for optical imaging. In one embodiment of the present disclosure, an optical imaging apparatus utilizes a laser-based coherent light source, and an optical device to pass grated light along an illumination direction from the laser-based coherent light source toward an object. Additionally, an illumination modulator is provided for changing angles at which the light, moving toward the object plane, reaches the object plane, and the light reaches the object plane at different angles. Further, the apparatus can include circuitry to process image-based data in response to and based on the light reaching the object plane at different angles for a user-viewable image of an object in proximity of the object plane.
1. An optical imaging apparatus, comprising:
a laser-based coherent light source;
an optical device configured and arranged to pass grated light along an illumination direction from the laser-based coherent light source toward an object plane;
an illumination modulator for changing angles at which the light, moving toward the object plane, reaches the object plane, wherefrom the light reaches the object plane at different angles;
a circuit configured and arranged to process image-based data in response to and based on the light reaching the object plane at different angles for a user-viewable image of an object in proximity of the object plane.
2. An optical imaging apparatus, according to claim 1 , wherein the optical device includes a grating for passing the light.
3. An optical imaging apparatus, according to claim 1 , wherein the optical device includes a uniform grating for passing the light.
4. An optical imaging apparatus, according to claim 1 , wherein the optical device includes a segmented grating for passing the light.
5. An optical imaging apparatus, according to claim 1 , wherein the optical device is configured and arranged to provide the grated light via segmented grating of the light.
6. An optical imaging apparatus, according to claim 1 , wherein the optical device is configured and arranged to provide the grated light via uniform grating of the light.
7. An optical imaging apparatus, according to claim 1 , further including a controller configured and arranged to cause the illumination modulator to change the angles.
8. An optical imaging apparatus, according to claim 1 , further including a scan mirror system.
9. A method comprising the steps of:
providing a spatially coherent light source for illumination of an object;
generating from a grating component N optical wavefronts containing the object's spatial amplitude variation; and
using an imaging system having an object-space collection numerical aperture of NA 0 and using a light-responsive device to detect at least N complex-amplitude images of the composite wavefronts propagating from the object and received by the imaging system.
10. The method of claim 9 , further including the step of digital processing of data from the detection of the at least N complex-amplitude images for constructing a resultant high-resolution image.
11. An optical imaging apparatus, comprising:
a spatially coherent light source for illumination of an object;
a grating component configured and arranged to generate N optical wavefronts containing the object's spatial amplitude variation;
an imaging system having an object-space collection numerical aperture of NA 0 ; and
a light-responsive device configured and arranged to detect at least N complex-amplitude images of the composite wavefronts propagating from the object and received by the imaging system.
12. The optical imaging apparatus of claim 11 , wherein the grating component is further configured and arranged to cause each of the N optical wavefronts to propagate in one of N different directions.
13. The optical imaging apparatus of claim 12 , wherein the angular spectrum associated with each of the N optical wavefronts has a unique bias angle.
14. The optical imaging apparatus of claim 11 , wherein the light-responsive device is further configured and arranged for acquiring the complex-amplitude images sequentially in at least N steps and in digital format.
15. The optical imaging apparatus of claim 11 , wherein the light-responsive device is further configured and arranged for detecting the complex-amplitude images by digital holography.
16. The optical imaging apparatus of claim 11 , further including a digital processing circuit configured and arranged for constructing, from N complex-amplitude images, a resultant high-resolution image.
17. The optical imaging apparatus of claim 16 , wherein the resultant high-resolution corresponds to an “effective” numerical aperture NA eff that is larger than the actual numerical aperture.
18. The optical imaging apparatus of claim 16 , wherein the resultant high-resolution corresponds to an “effective” numerical aperture NA eff that is larger than the actual numerical aperture, such that in the case of 1-D enhancement, NA eff can be as large as N*NA 0 .
19. The optical imaging apparatus of claim 16 , wherein the resultant high-resolution corresponds to an “effective” numerical aperture NA eff that is larger than the actual numerical aperture, such that in the case of 2-D enhancement, the resolution gain in a given direction depends on how the N object wavefronts are distributed in angle space.
20. The optical imaging apparatus of claim 16 , wherein the resultant high-resolution corresponds to an “effective” numerical aperture NA eff that is larger than the actual numerical aperture, such that a degree of overlap of the N angular spectra is provided to facilitate post-image-capture stitching of the spectra together in the presence of optical components.