JP2011128573A - Hologram image projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To focus laser light on a plurality of desired focal points in a sample even if there complexly exist causes of the generation of various aberration. <P>SOLUTION: A hologram image projector 1 includes: a laser light source 5; a wave front modulating element 12 which modulates the wave front of the laser light from the light source with a phase pattern; an objective lens 13 focusing the laser light to a sample (A); an incident angle adjusting portion 9 for adjusting an incident angle of the laser light into an entrance pupil position of the objective lens 13; a focal position determining portion 22 which determines positions of a plurality of focal points on which laser light is focused in the sample (A); a wave front measuring portion 25 for measuring wave fronts of backlight returning from the determined positions of each of focal points at the entrance pupil of the objective lens 13; and a wave front combining portion 26 for combining a plurality of the measured wave fronts; and a phase pattern setting portion 27 which sets a phase pattern added to the wave front modulating element 12 based on the calculated combined wave front and outputs it to the wave front modulating element 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hologram image projection apparatus.

Conventionally, it is known to use a hologram in order to simultaneously irradiate a plurality of locations on a specimen with light (see, for example, Non-Patent Document 1).
In this method, a fluorescence image of a specimen is acquired by a fluorescence microscope or the like, and a plurality of regions of interest that should be subjected to light stimulation or the like are specified in the acquired fluorescence image, thereby generating a stimulation light irradiation pattern. Is subjected to Fourier transform to create a hologram phase pattern. Then, the created phase pattern is applied to the wavefront modulation element, and laser light composed of substantially parallel light guided from the light source is incident on the wavefront modulation element, thereby modulating the laser light, and the modulated laser light. Is condensed by an objective lens. In this way, the hologram image is projected onto the specimen, and the stimulation light is condensed simultaneously at a plurality of locations.

Volodymyr Nikolenko et al, "SLM microscopy: scanless two-photon imaging and photostimulation with spatial light modulators", Frontiers in Neural Circuits, Vol 2, Article 5, 19 December 2008, p1-15

  However, in the conventional method, the refractive index in the sample to be observed is distributed and non-uniform, or there is an aberration in the optical system. There is an inconvenience that the laser beam cannot be condensed at this position. Further, in many cases, these causes occur in a complex manner, and there is a problem that it is difficult to specify each cause individually.

  The present invention has been made in view of the above-described circumstances, and even when various causes of aberrations exist in a complex manner, laser light is simultaneously applied to a plurality of desired condensing points in a sample. An object of the present invention is to provide a hologram image projection apparatus that can collect light.

In order to achieve the above object, the present invention provides the following means.
The present invention provides a laser light source, a wavefront modulation element that modulates a wavefront of laser light emitted from the laser light source by a phase pattern, an objective lens that focuses the laser light on a sample, and the objective lens of the laser light An incident angle adjusting unit that adjusts the incident angle to the entrance pupil position of the lens, a condensing position setting unit that sets the positions of a plurality of condensing points where the laser beam should be condensed in the sample, and the condensing position setting unit A wavefront measuring unit for measuring the wavefront of the return light returning from each condensing point at the position set by the entrance pupil position of the objective lens or its optically conjugate position, and a plurality of the wavefront measuring units measured by the wavefront measuring unit A wavefront synthesis unit that calculates a combined wavefront by combining the wavefronts of the return light, and sets the phase pattern to be applied to the wavefront modulation element based on the calculated combined wavefront. Providing a hologram image projection apparatus and a phase pattern setting unit for force.

  According to the present invention, when the sample is irradiated with laser light emitted from the laser light source, the wavefront at the entrance pupil position of the return light returning from each condensing point at the position set by the condensing position setting unit is measured by the wavefront measurement. Measured by the part. When the wavefront is measured, the wavefront combining unit calculates a combined wavefront by combining a plurality of wavefronts corresponding to the measured condensing points, and the phase pattern setting unit calculates the wavefront based on the calculated combined wavefront. A phase pattern to be applied to the modulation element is set, and the phase pattern is output to the wavefront modulation element. Then, with the set phase pattern applied to the wavefront modulation element, laser light is incident on the wavefront modulation element, so that the laser light having the combined wavefront is incident on the entrance pupil position of the objective lens, A hologram image having a plurality of condensing points is projected on the screen.

  In this case, according to the hologram image projector according to the present embodiment, the laser light is condensed at the condensing point by measuring the wavefronts of the return light from the plurality of condensing points that are actually present. Since the phase pattern is set, the laser beam can be simultaneously focused on a plurality of desired condensing points in the specimen even when various causes of various aberrations exist. it can.

In the above invention, the wavefront synthesis unit may calculate the synthesized wavefront by calculating a linear sum of wavefronts of a plurality of return lights measured by the wavefront measurement unit.
Further, in the above invention, the wavefront synthesizing unit arranges the wavefronts of the plurality of return lights measured by the wavefront measuring unit, which are divided into regions, at a ratio of the reciprocal number of the total number of the focusing points The composite wavefront may be calculated.

  Further, in the above invention, the wavefront measuring unit branches a laser beam to generate a reference beam, a multiplexing unit that combines the return beam and the reference beam from the point light source, You may provide the interference light detection part which detects the interference light of the said return light combined by this multiplexing part and the said reference light.

  By doing so, the laser light is branched by the branching portion, so that one laser light is directed to the specimen and illuminates the specimen, and the other laser light becomes the reference light. Then, the return light from the point light source arranged at the position of the condensing point set on the sample and the reference light are caused to interfere by being combined by the combining unit, and the interference light is detected by the interference light detecting unit. Detected. As a result, the interference light detector detects a minute difference between the wavefronts of the return light from the sample and the reference light, so that the wavefront of the laser light for condensing the laser light at the condensing point is used as the reference light. It is possible to measure precisely as the difference of.

In the above invention, the wavefront measurement unit includes a pinhole member disposed at a position optically conjugate with the focal position of the objective lens, and return light from the light condensing point that has passed through the pinhole member. And a Hartmann sensor for detecting.
By doing so, only the return light emitted from the focal position of the objective lens among the return lights returning from the specimen as a result of irradiating the specimen with the laser light is selected by the pinhole member and detected by the Hartmann sensor. Can do. Thereby, the wavefront of the return light from the point light source arranged at the focal position of the objective lens can be accurately measured.

  According to the present invention, there is an effect that laser light can be simultaneously focused on a plurality of desired condensing points in a sample even when various causes of aberrations exist in a complex manner. .

1 is an overall configuration diagram schematically showing a hologram image projector according to an embodiment of the present invention. It is a whole block diagram which shows the modification of the hologram image projector of FIG.

A hologram image projection apparatus according to an embodiment of the present invention will be described below with reference to the drawings.
The hologram image projector 1 according to the present embodiment is a microscope system, and as shown in FIG. 1, a light source device 2 that generates laser light and laser light incident from the light source device 2 are applied to a specimen A. A microscope apparatus 3 for irradiating and an adjusting apparatus 4 for adjusting the wavefront of laser light incident on the microscope apparatus 3 from the light source device 2 are provided.

  The light source device 2 includes a laser light source 5 that generates laser light, a collimator lens 6 that converts the laser light emitted from the laser light source 5 into collimated light, and a wavefront modulation unit that modulates the wavefront of the laser light composed of the collimated light. 7, relay lenses 8 and 10, and a scanner 9 that scans the laser beam.

  The wavefront modulation unit 7 reflects the laser beam reflected by the prism 11 and the laser beam reflected by the prism 11. At this time, the wavefront modulation unit 7 modulates the wavefront of the laser beam by the phase pattern and returns it to the prism 11. And a wavefront modulation element 12.

The laser beam reflected by the prism 11 is folded back so as to return to the same prism 11 by the wavefront modulation element 12, and returned to the optical path coaxial with the laser beam from the laser light source 5.
The wavefront modulation element 12 is configured by a segment type MEMS mirror whose surface shape can be arbitrarily changed by the adjusting device 4 described later. In this case, the surface shape formed by the unevenness of each segment of the MEMS mirror becomes a phase pattern for modulating the wavefront of the laser light. The wavefront modulation element 12 and the entrance pupil position of the objective lens 13 are arranged in an optically conjugate positional relationship.

  The scanner 9 is a so-called proximity galvanometer mirror in which two galvanometer mirrors 9a and 9b that can be swung around an axis arranged in a direction intersecting each other are arranged close to each other. Can be scanned automatically.

  The microscope apparatus 3 focuses the laser beam on the specimen A placed on the stage 14, while receiving the objective lens 13 that receives the light from the specimen A, and photoelectrons that detect the light received by the objective lens 13. A photo detector 15 composed of a multiplier tube, a camera 16 such as a CCD for taking a fluorescent image in the specimen A, and a mirror 17 inserted into and removed from the optical path so as to switch the optical path to the photo detector 15 or the camera 16. I have. Reference numerals 18 to 20 are condenser lenses, and reference numeral 21 is a dichroic mirror. The objective lens 13 is provided such that the distance in the optical axis direction between the objective lens 13 and the stage 14 can be changed.

By setting the surface shape of the wavefront modulation element 12 to a flat reflecting surface shape, laser light having a wavefront consisting of plane waves can be incident on the entrance pupil position of the objective lens 13. Thereby, the laser beam can be condensed on the focal plane of the objective lens 13.
In a state where the mirror 17 is switched to the light detector 15 side (position removed from the optical path indicated by the broken line), the laser light is emitted from the laser light source 5 and the scanner 9 is driven to collect on the focal plane in the sample A. The two-dimensional scanning of the specimen A spreading along the focal plane of the objective lens 13 is performed by detecting the fluorescence generated at each condensing position by the photodetector 15 while scanning the radiated laser beam two-dimensionally. A simple fluorescence image can be acquired.

  Then, by relatively moving the distance between the objective lens 13 and the stage 14 and changing the position of the focal plane of the objective lens 13, a plurality of two-dimensional fluorescence images (slice images) are acquired. A three-dimensional fluorescence image of the specimen A can be acquired.

  As shown in FIG. 1, the adjusting device 4 is based on the input unit 22 that sets the position information of the condensing point of the laser beam in the sample A, and the position information of each condensing point that is set by the input unit 22. A control unit 24 for controlling the scanner 9 and an optical path length adjusting prism 23 to be described later, a wavefront measuring unit 25 for measuring the wavefront of the return light from each condensing point at the position set by the input unit 22, A wavefront synthesizing unit 26 that synthesizes wavefronts of a plurality of return lights measured for the light spot, and a phase pattern setting that sets a phase pattern to be applied to the wavefront modulation element 12 based on the synthesized wavefront synthesized by the wavefront synthesizing unit 26 Part 27.

The input unit 22 sets the position information of each condensing point by designating a position on the monitor (not shown) where the observer wants to condense the laser beam.
Here, the condensing point in the sample A may be set at an arbitrary position or may be set at a position responding to the light stimulus. When it is desired to set the focal point to a position that responds to light stimulation, the monitor (not shown) displays an image acquired by the microscope device 3 so that the observer can easily designate the focal point. Is preferred.

  The wavefront measuring unit 25 is arranged in front of the wavefront modulating unit 7, and includes a polarization beam splitter 28 that branches the laser light into reference light and measuring light, and a wavefront modulating unit 7 provided in the measuring optical path 29 through which the measuring light passes. A polarization beam splitter 31 that is arranged in the subsequent stage and combines the return light of the measurement light from the sample A and the reference light that has passed through the reference light path 30, and the polarization of the laser light converted into parallel light by the collimator lens 6. Wavelength plate 32 whose direction is rotated at an arbitrary angle, wavelength plate 33 which converts laser light (measurement light) transmitted through polarization beam splitter 31 into circularly polarized light or rotates 45 °, and polarization beam splitter 31 are combined. And a detection light path 34 for detecting the reference light and the return light.

  The wave plate 32 is arranged to rotate the polarization direction of the laser light so that the polarization beam splitter 28 can split the laser light into the reference light and the measurement light at a predetermined light quantity ratio. In addition, the wavelength plate 33 changes the polarization direction by 90 ° until the measurement light transmitted through the polarization beam splitter 31 is collected on the sample A and the return light from the sample A is incident on the polarization beam splitter 31 again. It is arranged to rotate.

  The reference optical path 30 is provided so as to be movable along the optical axis, an optical path length adjusting prism 23 that adjusts the optical path length, a dispersion compensation plate 35 that compensates for group velocity dispersion, and the reference light incident on the polarization beam splitter 31. And a λ / 2 plate 36 for rotating the polarization direction of 90 °. Reference numeral 37 denotes a mirror.

  The detection light path 34 includes a polarizing plate 38 that transmits the return light transmitted through the wave plate 33 and the reference light transmitted through the λ / 2 plate 36 at a predetermined light amount ratio, a relay lens 39 that relays the pupil, and a return light. An interference light detection unit 40 that detects interference light generated by combining the light and the reference light is disposed.

Here, since the polarization directions of the return light transmitted through the wavelength plate 33 and the reference light transmitted through the λ / 2 plate 36 are substantially orthogonal to each other, the polarizing plate 38 is larger than 0 with respect to the polarization direction of each light. The transmission axis has an angle. Thereby, the polarizing plate 38 transmits only the component along the predetermined axis among the return light and the reference light.
The interference light detection unit 40 is arranged in a positional relationship optically conjugate with the entrance pupil positions of the wavefront modulation element 12 and the objective lens 13.

  The wavefront synthesis unit 26 is configured to synthesize wavefronts measured for all the condensing points. In the present embodiment, the wavefront synthesis unit 26 calculates a linear sum of wavefronts calculated for all the condensing points.

  The phase pattern setting unit 27 sets a phase pattern to be applied to the wavefront modulation element 12 based on the combined wavefront calculated by the wavefront synthesis unit 26 and outputs the phase pattern to the wavefront modulation element 12. Here, since the wavefront modulation element 12 is in a conjugate relationship with the entrance pupil of the objective lens 13, the phase pattern applied to the wavefront modulation element 12 is the same as or the phase of the combined wavefront at the entrance pupil position of the objective lens 13. Wrapping process. In the phase wrapping process, when the phase modulation range in the wavefront modulation element 12 is set to 2nπ (n is an integer), the portion having a phase difference exceeding 2nπ in the combined wavefront at the entrance pupil position of the objective lens 13 , By subtracting 2nπ from the phase difference. In the segment type MEMS mirror in the present embodiment, since the range of phase modulation is normally set to a range of 2nπ, phase wrapping processing is performed as necessary.

  In this way, the surface shape of the wavefront modulation element 12 is adjusted to a shape that matches the input phase pattern. As a result, the laser beam reflected by the wavefront modulation element 12 is modulated so as to have the same wavefront as the combined wavefront obtained at the entrance pupil position of the objective lens 13 on the surface of the wavefront modulation element 12. Therefore, such laser light is condensed by the objective lens 13 and is simultaneously condensed on each set condensing point while the objective lens 13 is fixed.

The operation of the hologram image projector 1 according to this embodiment configured as described above will be described below.
First, in the input unit 22, position information of each condensing point is set.
Here, when the condensing point is set at a position that responds to the light stimulus in the sample A, the wavefront modulation element 12 is set to a phase pattern having a flat reflecting surface shape by the output from the adjusting device 4. In the microscope apparatus 3, the mirror 17 is retracted from the optical path. Then, laser light is generated from the laser light source 5 and the laser light is scanned two-dimensionally by the scanner 9.

  The laser light emitted from the laser light source 5 is propagated through the optical path without changing the wavefront, scanned two-dimensionally by the scanner 9, reflected by the dichroic mirror 21, and incident on the objective lens 13 to enter the sample A. Focused on the focal plane. Fluorescence is generated at the condensing position of the laser beam, and the generated fluorescence is collected by the objective lens 13, passes through the dichroic mirror 21, is collected by the collecting lenses 19 and 20, and is detected by the photodetector 15. The

Since fluorescence is generated only in a very thin region near the focal plane of the objective lens 13, the intensity of the fluorescence detected by the photodetector 15 and the scanning position of the laser beam by the scanner 9 are stored in association with each other. Thus, a two-dimensional fluorescence image (slice image) of the specimen A extending along the focal plane can be acquired.
A three-dimensional fluorescence image can also be acquired by acquiring a plurality of slice images while relatively moving the objective lens 13 and the specimen A in the optical axis direction.

  The observer designates the position of the condensing point where the laser beam is to be condensed in the two-dimensional or three-dimensional fluorescent image displayed on a monitor (not shown). For example, in the case where the specimen A is a nerve cell and the behavior is observed by applying a stimulus by laser light, the focal points to which the stimulus is desired are distributed three-dimensionally. In this case, the observer sets the three-dimensional position information of the condensing point by designating all the condensing points.

Next, the wavefront measuring unit 25 measures the wavefront for each set condensing point.
That is, based on the position coordinates of each condensing point set from the input unit, the control unit 24 operates the scanner 9 to irradiate the condensing point with laser light one by one. At this time, the control unit 24 adjusts the position of the optical path length adjusting prism 23 so that the optical path length of the reference optical path 30 matches the optical path length of the measurement optical path 29 from the input unit 22 to each condensing point. At this time, the wavefront modulation element 12 is set to a phase pattern having a flat reflecting surface shape.

  The laser light emitted from the laser light source 5, for example, having a longitudinal polarization plane is passed through the wave plate 32, the polarization direction thereof is rotated by a predetermined angle, and is incident on the polarization beam splitter 28. . In the polarization beam splitter 28, the light beam is divided into a vertical polarization component and a horizontal polarization component, and one of them, for example, the vertical polarization component is incident on the reference optical path 30 and the other is incident on the measurement optical path 29.

  The longitudinally polarized light component directed to the reference optical path 30 is dispersion-compensated when passing through the dispersion compensation plate 35, is turned back by the optical path length adjusting prism 23, and then the polarization direction is rotated by 90 ° by the λ / 2 plate 36. And becomes a laterally polarized light component. The laser light from the reference optical path 30 that has become the lateral polarization component is transmitted through the polarization beam splitter 31 and is incident on the detection optical path 34.

  On the other hand, the lateral polarization component transmitted through the polarization beam splitter 28 enters the measurement optical path 29, is reflected by the prism 11 and the wavefront modulation element 12, passes through the polarization beam splitter 31, and passes through the wave plate 33. It is done. As a result, the laser light that has been converted into circularly polarized light or whose polarization direction has been rotated by 45 ° passes through the relay lens 8 and is then given an angle for being directed to a desired condensing point by the scanner 9. Then, after passing through the relay lens 10, the light enters the microscope apparatus 3.

  The laser light incident on the microscope apparatus 3 is reflected by the dichroic mirror 21 and condensed on the specimen A by the objective lens 13. The laser beam reflected in the region near the condensing point in the sample A is received by the objective lens 13, then reflected by the dichroic mirror 21, and returned through the relay lens 10, the scanner 9, and the relay lens 8, and the wave plate It is converted into a longitudinally polarized light component by 33 and is incident on the polarization beam splitter 31.

  The laser beam composed of the longitudinally polarized component incident on the polarization beam splitter 31 is reflected by the polarization beam splitter 31 and enters the detection optical path 34. At this time, the laser beam composed of the vertically polarized component is combined with the laser beam composed of the horizontally polarized component that has passed through the reference optical path 30. Then, only the component along the transmission axis of the polarizing plate 38 is transmitted through the polarizing plate 38 with respect to the laser light including the longitudinally polarized component that is the return light from the specimen A and the laser light including the laterally polarized component that is the reference light. Then, the light enters the interference light detection unit 40 via the relay lens 39. Here, since the polarization directions of the return light and the reference light transmitted through the polarizing plate 38 coincide with each other, interference between the return light and the reference light is possible. Further, since the optical path length of the reference optical path 30 and the optical path length of the measurement optical path 29 up to the condensing point are matched by the optical path length adjusting prism 23, only the return light returning from the condensing point interferes with the reference light. .

Thereby, in the interference light detection part 40, the difference of the wave front of the laser beam emitted from the laser light source 5 and the wave front of the laser beam which is the return light from the condensing point is detected as an interference pattern.
When the wavefront is measured by performing the above operation for all the condensing points, a linear sum of the wavefronts measured for each condensing point is calculated by the wavefront synthesizing unit 26, and a synthetic wavefront is generated. The generated combined wavefront is input to the phase pattern setting unit 27, and the phase pattern applied to the wavefront modulation element 12 is set to be the same as the combined wavefront at the entrance pupil position of the objective lens 13 or a phase-wrapped pattern. Is done. Then, the phase pattern set by the phase pattern setting unit 27 is output to the wavefront modulation element 12.
Thereby, the preparation for observing the specimen A while performing light stimulation is completed.

  In this state, in the microscope apparatus 3, the mirror 17 is inserted on the optical path (positioned at a position indicated by a solid line in the drawing), and the fluorescence condensed by the objective lens 13 is photographed by the camera 16. Set it. Then, when the laser light emitted from the laser light source 5 is incident on the wavefront modulation unit 7 with the scanner 9 stopped at the origin position, the wavefront of the laser light is modulated according to the phase pattern displayed on the wavefront modulation element 12. Is done. The modulated laser light passes through the relay lens 8, the scanner 9, and the relay lens 10, is reflected by the dichroic mirror 21, and enters the entrance pupil of the objective lens 13.

Since the entrance pupil position of the objective lens 13 is disposed at a position optically conjugate with the wavefront modulation element 12, the laser light incident on the entrance pupil position is the same as the wavefront when modulated by the wavefront modulation element 12. Has a wavefront.
Then, when such laser light is condensed by the objective lens 13, a three-dimensional hologram image is projected into the specimen A so as to be simultaneously condensed at a plurality of condensing points arranged at different positions. can do.

  By irradiating laser light to a plurality of designated condensing points at the same time, the fluorescence emitted from the specimen A is received by the objective lens 13 while the specimen A is stimulated, and passes through the dichroic mirror 21. Then, it is reflected by the mirror 17, condensed by the condenser lens 18, and photographed by the camera 16. Thereby, the fluorescence image of the sample A when a light stimulus is given can be acquired.

  Thus, according to the hologram image projector 1 according to the present embodiment, the combined wavefront formed by combining the wavefronts obtained by measuring the return light from the point light sources arranged at all the condensing points, Since the wavefront of the laser light is adjusted so as to be incident on the entrance pupil position of the objective lens 13, the laser light can be accurately focused simultaneously on a plurality of condensing points to give the specimen A a light stimulus. As a result, when the condensing point is set in the specimen A at a position that responds to the light stimulus, there is an advantage that the behavior of the specimen A generated immediately after the light stimulus can be accurately observed without a time difference.

  In this case, according to the present embodiment, since the wavefront corresponding to each condensing point is obtained by measurement, even if various aberrations for which the cause of occurrence is not present can be identified. There is an advantage that the laser beam can be accurately condensed at each condensing point with sufficient compensation.

  In the present embodiment, the wavefront measuring unit 25 divides the laser light into reference light and measurement light, and matches the optical path lengths of the reference light path 30 and the measurement light path 29 so that the reference light and the return light are combined. Although the method of measuring the wavefront by causing interference is adopted, instead of this, a method of combining the confocal pinhole 41 and the Hartmann sensor 42 may be adopted as shown in FIG. .

  That is, in the example shown in FIG. 2, the polarizing beam splitter 28 and the reference optical path 30 are eliminated, and instead of this, a confocal pinhole 41 is disposed in the detection optical path 34, and a Hartmann sensor is substituted for the interference light detection unit 40. 42 is adopted. By placing the confocal pinhole 41 at a position optically conjugate with the focal position of the objective lens 13, only the return light from the point light source arranged at the focal position is detected by the Hartmann sensor 42, Wavefront can be measured.

  In this figure, the wave plate 32 rotates the plane of polarization so that the polarization direction of the laser light emitted from the laser light source 5 matches the polarization direction that can be transmitted through the polarization beam splitter 31.

  In the present embodiment, the wavefront synthesis in the wavefront synthesis unit 26 is performed by calculating the linear sum of the wavefronts. Instead, a plurality of wavefronts calculated for each condensing point are used. It is good also as performing by dividing | segmenting the area | region into the ratio of the reciprocal number of the total number of condensing points.

  Specifically, when the total number of the condensing points is n, the area on the wavelength modulation element 12 is divided without calculating the linear sum of the wavefronts calculated for each condensing point, and the divided areas are divided. One of a plurality of condensing points is associated with each other. At this time, it is preferable to perform the association so that the corresponding region of each condensing point is periodically distributed at a ratio of the reciprocal of the total number n of condensing points. Further, the distribution of the corresponding region of each condensing point may be a mosaic shape or a concentric shape. After making such association, a wavefront element of a portion overlapping with a corresponding region on the wavelength modulation element 12 is extracted from the wavefronts calculated from the respective condensing points, and all the extracted wavefront elements are extracted. Arrange over the area to synthesize the wavefront. A phase pattern to be applied to the wavelength modulation element 12 is set based on the composite wavefront obtained in this way.

  Further, in the present embodiment, as the wavefront modulation element 12, a segment type MEMS mirror whose surface shape is changed is exemplified, but instead of this, any other wavefront modulation element 12, for example, a liquid crystal element, a deformer, etc. A bull mirror or the like may be used. In the case of a liquid crystal element, the refractive index distribution due to the orientation of liquid crystal molecules is a phase pattern, and in the case of a deformable mirror, the surface shape is a phase pattern.

A Specimen 1 Hologram image projector 5 Laser light source 9 Scanner (incident angle adjustment unit)
12 Wavefront Modulating Element 13 Objective Lens 22 Input Unit (Condensing Position Setting Unit)
25 Wavefront Measurement Unit 26 Wavefront Synthesis Unit 27 Phase Pattern Setting Unit 31 Polarizing Beam Splitter (Multiplexing Unit)
40 Interference light detector 41 Confocal pinhole (pinhole member)
42 Hartmann sensor

Claims (5)

A laser light source;
A wavefront modulation element that modulates a wavefront of laser light emitted from the laser light source with a phase pattern;
An objective lens for condensing the laser light on a specimen;
An incident angle adjusting unit for adjusting an incident angle of the laser beam to an entrance pupil position of the objective lens;
A condensing position setting unit for setting the positions of a plurality of condensing points on which laser light is to be collected in the sample;
A wavefront measuring unit that measures the wavefront at the entrance pupil position of the objective lens of the return lens or the optically conjugate position of the return light returning from each condensing point at the position set by the condensing position setting unit;
A wavefront synthesis unit that calculates a synthesized wavefront by synthesizing a plurality of wavefronts of the return light measured by the wavefront measurement unit;
A phase pattern setting unit that sets the phase pattern to be applied to the wavefront modulation element based on the calculated composite wavefront and outputs the phase pattern to the wavefront modulation element;
A hologram image projection apparatus comprising:   The hologram image projection apparatus according to claim 1, wherein the wavefront synthesis unit calculates the composite wavefront by calculating a linear sum of wavefronts of the plurality of return lights measured by the wavefront measurement unit.   The wavefront synthesizing unit calculates the synthesized wavefront by arranging regions obtained by dividing the wavefronts of the plurality of return lights measured by the wavefront measuring unit at a ratio of the reciprocal of the total number of the condensing points. Item 4. The hologram image projector according to Item 1.   The wavefront measuring unit divides laser light to generate reference light, a multiplexing unit that combines the return light from the point light source and the reference light, and multiplexing by the multiplexing unit 4. The hologram image projection apparatus according to claim 1, further comprising: an interference light detection unit configured to detect interference light between the returned light and the reference light.   A pinhole member disposed at a position optically conjugated with the focal position of the objective lens; and a Hartmann sensor for detecting return light from the condensing point that has passed through the pinhole member; A hologram image projection apparatus according to claim 1, comprising:

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