HOLOGRAPHIC IMAGE PROJECTION METHOD AND HOLOGRAPHIC IMAGE PROJECTION SYSTEM

• US 20110267663A1
• Filed: 12/15/2010
• Published: 11/03/2011
• Est. Priority Date: 12/21/2009
• Status: Abandoned Application

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Murayama, Yoshiaki
• Application Number:
  US12/968,970
• Publication Number:
  US 20110267663A1
• Time in Patent Office: Days
• US Class Current: 359/9
• CPC Class Codes: G03H 1/08 Synthesising holograms, i.e. holograms synthesized from objects or objects from hologramsusing electric digital computers G06F; G06T
• CPC Class Codes: G03H 1/2249 Holobject properties
• CPC Class Codes: G03H 1/2294 Addressing the hologram to an active spatial light modulator
• CPC Class Codes: G03H 2001/2213 Diffusing screen revealing the real holobject, e.g. container filed with gel to reveal the 3D holobject
• CPC Class Codes: G03H 2210/30 3D object
• CPC Class Codes: G03H 2225/32 Phase only

Abstract

Provided is a hologram-image projection method including a step of setting three-dimensional position information in a specimen for a plurality of focal points where laser light is to be focused via an objective lens; a step of performing reverse ray tracing from the individual focal points to an entrance pupil position of the objective lens by using the position information set for the individual focal points in the specimen, a refractive index of the specimen, and overall characteristic data of the objective lens, to calculate a wavefront of the laser light at the entrance pupil position from the individual focal points; a step of calculating a combined wavefront by combining the plurality of calculated wavefronts; a step of setting a phase pattern to be applied to a wavefront modulating device on the basis of the calculated combined wavefront; and a step of applying the set phase pattern to the wavefront modulating device, causing the laser light to be incident thereon, and focusing the laser light whose wavefront is modulated by the phase pattern on the specimen via the objective lens.

Claims

1. A hologram-image projection method comprising:

a position setting step of setting three-dimensional position information in a specimen for a plurality of focal points where laser light is to be focused via an objective lens;

a wavefront calculating step of performing reverse ray tracing from the individual focal points assumed at set positions to an entrance pupil position of the objective lens by using the position information set for the individual focal points in the specimen, a refractive index of the specimen, and overall characteristic data of the objective lens, to calculate wavefronts of the laser light at the entrance pupil position from the individual focal points;

a wavefront combining step of calculating a combined wavefront by combining the plurality of wavefronts calculated for the individual focal points;

a phase-pattern setting step of setting a phase pattern to be applied to a wavefront modulating device on the basis of the calculated combined wavefront; and

a focusing step of applying the set phase pattern to the wavefront modulating device, causing the laser light to be incident thereon, and focusing the laser light whose wavefront is modulated by the phase pattern on the specimen via the objective lens.

2. A hologram-image projection method according to claim 1, wherein the wavefront combining step is a step of calculating the combined wavefront by calculating a linear summation of the plurality of wavefronts.

3. A hologram-image projection method according to claim 1, wherein the wavefront combining step is a step of calculating the combined wavefront by arraying respective divided regions of the plurality of wavefronts with a ratio equal to the reciprocal of the number of focal points.

4. A hologram-image projection method comprising:

a position setting step of setting three-dimensional position information in a specimen for a plurality of focal points where laser light is to be focused via an objective lens;

a virtual-image creating step of creating a virtual image in which the individual focal points are projected on a prescribed reference plane in the specimen using the set position information of the individual focal points in the specimen;

a wavefront calculating step of calculating a wavefront of the laser light at an entrance pupil position of the objective lens by Fourier transforming the created virtual image using the refractive index of the specimen and overall characteristic data of the objective lens;

a phase-pattern setting step of setting a phase pattern to be applied to a wavefront modulating device on the basis of the calculated wavefront; and

a focusing step of applying the set phase pattern to the wavefront modulating device, causing the laser light to be incident thereon, and focusing the laser light whose wavefront is modulated by the phase pattern on the specimen via the objective lens.

5. A hologram-image projection method according to claim 4, wherein:

the position setting step includes a plane position setting step of setting plane position information in the specimen for the plurality of focal points, and a depth-information setting step of setting depth information relative to the reference plane for the individual focal points;

the virtual-image creating step includes a first-virtual-image creating step of creating a first virtual image for when it is assumed that the individual focal points are focused on a prescribed reference plane in the specimen to form a plurality of spots, by using the plane position information in the specimen for the individual focal points, and a second-virtual-image creating step of creating a second virtual image by correcting a corresponding spot in the first virtual image on the basis of the set depth information of the individual focal points.

6. A hologram-image projection method according to claim 5, wherein the second-virtual-image creating step is a step of correcting the corresponding spot in the first virtual image by substituting the spot in the first virtual image with a spots of the laser light obtained by ray tracing the laser light focused at the individual focal points up to the reference plane.

7. A hologram-image projection method according to claim 5, wherein the second-virtual-image creating step includes a step in which, with the objective lens disposed so that a focal position of the objective lens is displaced from the reference plane by a prescribed distance in the optical axis direction, a coefficient of proportionality is calculated by dividing a change in vector information, occurring when vector information representing aberrations at a focal plane of the objective lens varied, by the prescribed distance so that light is focused at the reference plane, and a step of correcting the spots using vector information obtained by multiplying the coefficient of proportionality and the depth information for each spot.

8. A hologram-image projecting apparatus comprising:

a wavefront modulating device that modulates a wavefront of laser light with a phase pattern;

an objective lens that focuses the laser light modulated by the wavefront modulating device on a specimen;

a position-information setting section for setting three-dimensional position information in the specimen for a plurality of focal points where the laser light is to be focused via the objective lens;

a wavefront calculating section that performs reverse ray tracing from the individual focal points assumed at set positions to an entrance pupil position of the objective lens by using the position information, inside the specimen, set for the individual focal points by the position-information setting section, a refractive index of the specimen, and overall characteristic data of the objective lens, to calculate wavefronts of the laser light at the entrance pupil position from the individual focal points;

a wavefront combining section that calculates a combined wavefront by combining the plurality of wavefronts calculated by the wavefront calculating section for the individual focal points; and

a phase-pattern setting section that sets the phase pattern to be applied to the wavefront modulating device on the basis of the calculated combined wavefront.

9. A hologram-image projecting apparatus comprising:

a wavefront modulating device that modulates a wavefront of laser light with a phase pattern;

an objective lens that focuses the laser light modulated by the wavefront modulating device on a specimen;

a position-information setting section for setting three-dimensional position information, inside the specimen, for a plurality of focal points where the laser light is to be focused via the objective lens;

a virtual-image creating section of creating a virtual image in which the individual focal points are projected on a prescribed reference plane in the specimen by using the position information, inside the specimen, set for the individual focal points by the position-information setting section;

a wavefront calculating section that calculates a wavefront of the laser light at an entrance pupil position of the objective lens by Fourier transforming the virtual image created by the virtual-image creating section using a refractive index of the specimen and overall characteristic data of the objective lens; and

a phase-pattern setting section that sets the phase pattern to be applied to the wavefront modulating device on the basis of the calculated wavefront.

10. A hologram-image projection method comprising:

a position setting step of setting, for a plurality of focal points where laser light is to be focused via an objective lens, position information on a focal plane of the objective lens in the specimen;

a wavefront calculating step of performing reverse ray tracing from the individual focal points assumed at set positions to an entrance pupil position of the objective lens by using the position information, in the specimen, set for the individual focal points, a refractive index of the specimen, and lens data of individual lenses constituting the objective lens, to calculate wavefronts of the laser light at the entrance pupil position from the individual focal points;

a wavefront combining step of calculating a combined wavefront by combining the plurality of wavefronts calculated for the individual focal points;

a phase-pattern setting step of setting a phase pattern to be applied to a wavefront modulating device on the basis of the calculated combined wavefront; and

a focusing step of applying the set phase pattern to the wavefront modulating device, causing the laser light to be incident thereon, and focusing the laser light whose wavefront is modulated by the phase pattern on the specimen via the objective lens.

11. A hologram-image projection method according to claim 10, wherein the wavefront combining step is a step of calculating the combined wavefront by calculating a linear summation of the plurality of wavefronts.

12. A hologram-image projection method according to claim 10, wherein the wavefront combining step is a step of calculating the combined wavefront by arraying respective divided regions of the plurality of wavefronts with a ratio equal to the reciprocal of the number of focal points.

13. A hologram-image projection method comprising:

a position setting step of setting, for a plurality of focal points where laser light is to be focused via an objective lens, position information on a focal plane of the objective lens in the specimen;

a virtual-image creating step of creating a virtual image having a plurality of spots formed at the individual focal points, by performing forward ray tracing from an entrance pupil position of the objective lens to the focal plane using the position information, in the specimen, set for the individual focal points, a refractive index of the specimen, and lens data of individual lenses constituting the objective lens;

a wavefront calculating step of calculating the wavefront so that, by varying the wavefront of the laser light at the entrance pupil position of the objective lens, the diameters of the individual spots in the created virtual image are minimized;

a phase-pattern setting step of setting a phase pattern to be applied to a wavefront modulating device on the basis of the calculated wavefront; and

a focusing step of applying the set phase pattern to the wavefront modulating device, causing the laser light to be incident thereon, and focusing the laser light whose wavefront is modulated by the phase pattern on the specimen via the objective lens.

14. A hologram-image projection method according to claim 13, wherein

the position information is a focal-point map including the plurality of focal points, which are assumed to be on the focal plane of the objective lens in the specimen;

the virtual-image creating step includes a step of calculating the wavefront of the laser light at the entrance pupil position of the objective lens by Fourier transforming the focal-point map, and a step of creating the virtual image by performing forward ray tracing from the entrance pupil position of the objective lens to the focal plane, for the laser light having the calculated wavefront, by using the refractive index of the specimen and the lens data of the individual lenses constituting the objective lens.

15. A hologram-image projecting apparatus comprising:

a wavefront modulating device that modulates a wavefront of laser light with a phase pattern;

an objective lens that focuses the laser light modulated by the wavefront modulating device on a specimen;

a position-information setting section for setting, for a plurality of focal points on a focal plane where laser light is to be focused via an objective lens, position information on the focal plane of the objective lens in the specimen;

a wavefront calculating section that performs reverse ray tracing from the individual focal points assumed at the set positions to an entrance pupil position of the objective lens by using the position information of the individual focal points set by the position-information setting section, a refractive index of the specimen, and lens data of individual lenses constituting the objective lens to calculate wavefronts of the laser light at the entrance pupil position from the individual focal points;

a wavefront combining section that calculates a combined wavefront by combining the plurality of wavefronts calculated for the individual focal points; and

a phase-pattern setting section that sets the phase pattern to be applied to the wavefront modulating device on the basis of the calculated combined wavefront.

16. A hologram-image projection apparatus comprising:

a laser light source;

a wavefront modulating device that modulates a wavefront of laser light emitted from the laser light source with a phase pattern;

an objective lens that focuses the laser light on a specimen;

an incident-angle adjusting section that adjusts an incident angle of the laser light at the entrance pupil position of the objective lens;

a focal-position setting section that sets the positions of a plurality of focal points where the laser light is to be focused in the specimen;

a wavefront measuring section that measures wavefronts, at the entrance pupil position of the objective lens, or a position optically conjugate therewith, for return light returning from the individual focal points at the positions set by the focal-position setting section;

a wavefront combining section that calculates a combined wavefront by combining the plurality of wavefronts of the return light measured by the wavefront measuring section; and

a phase-pattern setting section that sets the phase pattern to be applied to the wavefront modulating device on the basis of the calculated combined wavefront and outputs the phase pattern to the wavefront modulating device.

17. A hologram-image projection apparatus according to claim 16, wherein the wavefront combining section calculates the combined wavefront by calculating a linear summation of the plurality of return light wavefronts measured by the wavefront measuring section.

18. A hologram-image projection apparatus according to claim 16, wherein the wavefront combining section calculates the combined wavefront by arraying respective divided regions of the plurality of return light wavefronts measured by the wavefront measuring section with a ratio equal to the reciprocal of the number of focal points.

19. A hologram-image projection apparatus according to claim 16, wherein the wavefront measuring section includes a splitting portion that generates reference light by splitting the laser light;

a combining section that combines the reference light and the return light from the focal point; and

an interference-light detector that detects interference light of the return light and the reference light combined by the combining section.

20. A hologram-image projection apparatus according to claim 16, wherein the wavefront measuring section includes a pinhole member disposed at a position that is optically conjugate with the focal position of the objective lens;

and a Hartmann sensor that detects the return light from the focal point, which has passed through the pinhole member.