Holographic microscope, microscopic subject hologram image recording method, method of creation of hologram for reproduction of high-resolution image, and method for reproduction of image

A method for recording a hologram image of a microscopic subject, comprising the steps of:

• obtaining a complex amplitude hologram (JLR) as a reference light wave obtaining process by recording an interference fringe pattern (ILR) made by an in-line spherical wave light (L) and an off-axis reference light (R) using a photodetector, and performing a spatial frequency filtering on the recorded interference fringe pattern (ILR) to obtain the complex amplitude hologram (JLR) having recorded the off-axis reference light (R);
• recording an object light (O) emitted from a microscopic subject by illuminating the microscopic subject with a spherical wave light (L or L2) having the same focal point as that of the in-line spherical wave light (L) as an off-axis hologram (IOR) using the off-axis reference light (R) and the photodetector;
• obtaining a complex amplitude off-axis hologram (JOR) as a complex amplitude obtaining process by performing a spatial frequency filtering on the off-axis hologram (IOR);
• and
• recording a complex amplitude in-line hologram (JOL) generated by eliminating a component of the reference light (R) from the complex amplitude off-axis hologram (JOR) by dividing data of the complex amplitude off-axis hologram (JOR) obtained in the complex amplitude obtaining process by data of the complex amplitude hologram (JLR) obtained in the reference light wave obtaining process.

A method for reconstructing an image from a complex amplitude in-line hologram (JOL)of a microscopic subject obtained using an in-line spherical wave light (L or L2), comprising the steps of:

• increasing a number of pixels substantially as a pixel number increase process by subdividing the spatial sampling interval of the complex amplitude in-line hologram (JOL), and performing a data interpolation on a new sampling point produced by the subdividing;
• generating an object light complex amplitude in-line hologram (g) expressing an object light on a hologram plane by performing a spatial heterodyne modulation, to eliminate a component of the in-line spherical wave light (L) using beforehand obtained phase (ϕL) of the in-line spherical wave light (L), on the complex amplitude in-line hologram (JOL) having an increased number of pixels increased in the pixel number increase process;
• and
• expanding the object light (O) as a plane wave expansion process by using spatial frequencies (u, v, w) satisfying the dispersion relation of a plane wave and a transform function (G) derived as a result of Fourier-transforming of the object light complex amplitude in-line hologram (g), wherein
• the method generates a light wave (h) on a hologram plane or on an arbitrary position before and behind thereof.

A method for reconstructing an image from a complex amplitude in-line hologram (JOL) of a microscopic subject obtained using an in-line spherical wave light (L or L2), comprising the steps of:

• generating a plurality of minute holograms (gi′) having a substantially increased number of pixels as a division interpolation process, wherein the minute holograms (gi′) are generated by subdividing the spatial sampling interval of the complex amplitude in-line hologram (JOL) performing a data interpolation on each new sampling point produced by the subdividing, and dividing the complex amplitude in-line hologram (JO having a substantially increased number of pixels into the plurality of minute holograms;
• generating each of object light complex amplitude in-line holograms (gj) corresponding to each of the holograms (gi′) and expressing the object light on a hologram plane as a spatial modulation process by performing a spatial heterodyne modulation, to eliminate a component of the in-line spherical wave light (L) using beforehand obtained phase (ϕL) of the in-line spherical wave light (L), on each of the minute holograms (gi′) having the increased number of pixels increased in the division interpolation process;
• generating a synthetic minute hologram (Σ) as a hologram composing process by piling up mutually each of the object light complex amplitude in-line holograms (gj) generated by the spatial modulation process;
• and
• generating an image on a hologram plane or on an arbitrary position before and behind thereof as an image generation process by deriving a transform function (G) as a result of Fourier-transform of the synthetic minute hologram (Σ) generated by the hologram composing process and expanding the object light (O) using the transform function (G) and spatial frequencies (u, v, w) satisfying the dispersion relation of a plane wave.

A method for reconstructing an image of a microscopic subject through numerical computations from a complex amplitude in-line hologram (JOL) which was generated by processing a hologram obtained by illuminating the microscopic subject using an in-line spherical wave light (L or L2) as an illumination light and which contains information of the in-line spherical wave light (L) and information of an object light (O) emitted from the microscopic subject, comprising the steps of:

• generating an object light complex amplitude in-line hologram (g) expressing the object light (O) on a hologram plane by performing a spatial heterodyne modulation, to eliminate a component of the in-line spherical wave light (L), by multiplying the complex amplitude in-line hologram (JOL)by a phase factor (exp(iϕL)) made of beforehand obtained phase (ϕL) of the in-line spherical wave light (L), on the complex amplitude in-line hologram (JOL);
• dividing the object light complex amplitude in-line hologram (g) into a plurality of minute holograms (gi);
• generating each of low frequency minute hologram (gi·exp (−iϕi)) of reduced spatial frequency by performing a spatial heterodyne modulation on each of the minute holograms (gi) by multiplying each of the minute holograms (gi) by a phase factor (exp(−ϕi)) made of phase (ϕi) of a parallel light (Li) going to the center of each of the minute holograms (gi) from the focal point of the in-line spherical wave light (L), respectively;
• obtaining each of divided transform functions (G′i) as a result of discrete Fourier-transforming of each of the low frequency minute holograms (gi·exp(−iϕi)), respectively;
• and
• generating an image on a hologram plane or on an arbitrary position before and behind thereof by generating each of divided transform functions (G′i·exp(iϕi)) of increased spatial frequency by performing a spatial heterodyne modulation on each of the divided transform functions (G′i), by multiplying each of the divided transform functions (G′i) by the reciprocal of the phase factor (exp(−iϕi)) used for generating the low frequency minute hologram (gi·exp(−iϕi)), respectively, and carrying out a plane wave expansion to get the object light (O) on the arbitrary position using a transform function (G) composed of whole of those divided transform functions (G′i·exp(i ϕi)) of increased spatial frequency as weighting for superposing plane waves in the expansion and spatial frequencies (u, v, w) satisfying the dispersion relation of a plane wave.

A method for reconstructing an image of a microscopic subject through numerical computations from a complex amplitude in-line hologram (JOL), which was generated by processing a hologram obtained by illuminating the microscopic subject using an in-line spherical wave light (L or L2) as an illumination light and which contains information of the in-line spherical wave light (L) and information of an object light (O) emitted from the microscopic subject, comprising the steps of:

• generating an object light complex amplitude in-line hologram (g) expressing the object light (O) on a hologram plane by performing a spatial heterodyne modulation, to eliminate a component of the in-line spherical wave light (L), by multiplying the complex amplitude in-line hologram (JOL)by a phase factor (exp(iϕL)) made of beforehand obtained phase (ϕL)of the in-line spherical wave light (L), on the complex amplitude in-line hologram (JOL);
• dividing the object light complex amplitude in-line hologram (g) into a plurality of minute holograms (gi);
• generating each of divided transform functions (Gi) as a result of discrete Fourier-transforming of each of the minute holograms (gi), respectively;
• and
• generating an image on a hologram plane or on an arbitrary position before and behind thereof by carrying out a plane wave expansion to get the object light (O) on the arbitrary position using a transform function (G) composed of whole of those divided transform functions (Gi) as weighting for superposing plane waves in the expansion and spatial frequencies (u, v, w) satisfying the dispersion relation of a plane wave.

A method for reconstructing an image from a complex amplitude in-line hologram (JOL) of a microscopic subject obtained using an in-line spherical wave light (L or L2), comprising the steps of:

• generating a plurality of minute holograms (gi′) having a substantially increased number of pixels as a division interpolation process, wherein the minute holograms (gi′) are generated by dividing the complex amplitude in-line hologram (JOL)into a plurality of minute holograms, subdividing the spatial sampling interval of each of the minute holograms, and performing a data interpolation on a new sampling point produced by the subdividing;
• generating each of object light complex amplitude in-line holograms (gj)corresponding to each of the holograms (gi′)and expressing the object light on a hologram plane as a spatial modulation process by performing a spatial heterodyne modulation, to eliminate a component of the in-line spherical wave light (L) using beforehand obtained phase (ϕL) of the in-line spherical wave light (L), on each of the minute holograms (gi′)having the increased number of pixels increased in the division interpolation process;
• generating a synthetic minute hologram (Σ) as a hologram composing process by piling up mutually each of the object light complex amplitude in-line holograms (gj) generated by the spatial modulation process;
• and
• generating an image on a hologram plane or on an arbitrary position before and behind thereof as an image generation process by deriving a transform function (G) as a result of Fourier-transform of the synthetic minute hologram (Σ) generated by the hologram composing process and expanding the object light (O) using the transform function (G) and spatial frequencies (u, v, w) satisfying the dispersion relation of a plane wave.