APPARATUS AND METHOD FOR IRRADIATING A MEDIUM

• US 20110071402A1
• Filed: 09/24/2009
• Published: 03/24/2011
• Est. Priority Date: 09/24/2009
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Masumura, Takahiro
• Granted Patent: US 9,057,695 B2
• Time in Patent Office: Days
• US Class Current: 600/476
• CPC Class Codes: A61B 5/0097 by applying acoustic waves and detecting light, i.e. acoustooptic measurements
• CPC Class Codes: G01N 2021/1727 Magnetomodulation
• CPC Class Codes: G01N 21/1717 with a modulation of one or more physical properties of the sample during the optical investigation, e.g. electro-reflectance
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B
• CPC Class Codes: G03H 1/0005 Adaptation of holography to specific applications holographic optical element G02B5/32; holographic scanner G02B26/106; recognition using holographic mask G06V10/88; holographic memories G11B7/0065, G11C13/042
• CPC Class Codes: G03H 1/02 Details of features involved during the holographic process; Replication of holograms without interference recording
• CPC Class Codes: G03H 1/04 Processes or apparatus for producing holograms G03H1/26 takes precedence
• CPC Class Codes: G03H 1/2205 using downstream optical component
• CPC Class Codes: G03H 1/2645 Multiplexing processes, e.g. aperture, shift, or wavefront multiplexing
• CPC Class Codes: G03H 1/28 superimposed holograms only
• CPC Class Codes: G03H 2001/0212 Light sources or light beam properties G03H1/06, G03H1/24 take precedence; corresponding details, see subgroups of G03H2222/00
• CPC Class Codes: G03H 2001/0467 Gated recording using pulsed or low coherence light source, e.g. light in flight, first arriving light
• 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 2001/2244 Means for detecting or recording the holobject
• CPC Class Codes: G03H 2001/2655 Time multiplexing, i.e. consecutive records wherein the period between records is pertinent per se
• CPC Class Codes: G03H 2210/62 Moving object
• CPC Class Codes: G03H 2222/10 Spectral composition
• CPC Class Codes: G03H 2260/36 Dynamic material where the lifetime of the recorded pattern is quasi instantaneous, the holobject is simultaneously reconstructed

Abstract

A method for irradiating a medium includes irradiating the medium with an electromagnetic wave which is scattered in the medium and modulated in frequency at a position in the medium; obtaining information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and a reference wave; and generating a phase conjugate wave, based on the obtained information, which irradiates the medium.

Claims

1. An apparatus comprising:

a first irradiating unit, including an electromagnetic wave source which emits an electromagnetic wave, to irradiate a medium with the electromagnetic wave which is scattered in the medium;

an ultrasound device which transmits an ultrasonic wave to the medium to modulate a frequency of the electromagnetic wave at a position in the medium; and

a second irradiating unit to irradiate a holographic material with a reference wave to record information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and the reference wave,

wherein the first irradiating unit, after the information is recorded on the holographic material, is configured to irradiate the holographic material so that the holographic material generates a reconstructed wave which irradiates the medium at the position in the medium.

2. The apparatus according to claim 1, wherein the reconstructed wave comprises a phase conjugate wave which travels to the position in the medium.

3. The apparatus according to claim 1, wherein the holographic material is irradiated to generate the reconstructed wave substantially in a direction opposite to a direction of the reference wave.

4. The apparatus according to claim 1, further comprising a controller to control an intensity of the reconstructed wave so that the intensity of the reconstructed wave is different from that of the electromagnetic wave used to obtain the modulated electromagnetic wave.

5. The apparatus according to claim 1, wherein the electromagnetic wave source generates a visible ray or a near infrared ray.

6. The apparatus according to claim 1, further comprising a photodetector to monitor the holographic material.

7. The apparatus according to claim 1, further comprising a photodetector to detect a signal output from the medium in response to irradiation thereof by the reconstructed wave.

8. The apparatus according to claim 1, further comprising an ultrasound detector to detect a signal output from the medium in response to irradiation thereof by the reconstructed wave.

9. The apparatus according to claim 8, wherein the first irradiating unit irradiates the holographic material with a pulse wave.

10. The apparatus according to claim 1, further comprising an image forming unit to form a tomographic image using a signal output from the medium in response to irradiation thereof by the reconstructed wave.

11. An apparatus comprising:

a first irradiating unit including a first electromagnetic wave source to irradiate a medium with an electromagnetic wave which is scattered in the medium;

an ultrasound device which transmits an ultrasonic wave to the medium to modulate a frequency of the electromagnetic wave at a position in the medium;

a second irradiating unit to irradiate a holographic material with a reference wave to record information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and the reference wave; and

a third irradiating unit including a second electromagnetic wave source to irradiate the holographic material so that the holographic material generates a reconstructed wave which irradiates the medium at the position in the medium.

12. The apparatus according to claim 11, wherein the reconstructed wave comprises a phase conjugate wave which travels to the position in the medium.

13. The apparatus according to claim 11, wherein the holographic material is irradiated by the third irradiating unit substantially in a direction opposite to a direction of the reference wave.

14. The apparatus according to claim 11, further comprising a controller to control an intensity of the reconstructed wave so that the intensity of the reconstructed wave is different from that of the electromagnetic wave used to obtain the modulated electromagnetic wave.

15. The apparatus according to claim 11, wherein the first irradiating unit comprises an electromagnetic wave source which generates a visible ray or a near infrared ray.

16. The apparatus according to claim 11, further comprising a photodetector to monitor the holographic material.

17. The apparatus according to claim 11, further comprising a detector to detect a signal output from the medium in response to irradiation thereof by the reconstructed wave.

18. The apparatus according to claim 11, further comprising an image forming unit to form a tomographic image using a signal output from the medium in response to irradiation thereof by the reconstructed wave.

19. A method for irradiating a medium, the method comprising:

irradiating a medium with an electromagnetic wave which is scattered in the medium and modulated in frequency at a position in the medium;

obtaining information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and a reference wave; and

generating a phase conjugate wave, based on the obtained information, which irradiates the medium.

20. The method according to claim 19, wherein an intensity of the reconstructed wave is different from that of the electromagnetic wave used to obtain the modulated electromagnetic wave.

21. The method according to claim 19, wherein the frequency of the electromagnetic wave is modulated by an ultrasonic wave.

22. The method according to claim 19, wherein the frequency of the modulated electromagnetic wave is equal to a frequency of the reference wave.

23. The method according to claim 19, wherein a wavelength of the electromagnetic wave ranges from 380 nm to 2500 nm.

24. The method according to claim 19, wherein the information is obtained by using a holographic material.

25. The method according to claim 19, wherein the information is obtained by using a digital holographic technique.

26. The method according to claim 19, further comprising:

detecting a signal output from the medium in response to irradiation thereof by the phase conjugate wave; and

forming a tomographic image using the detected signal.

27. The method according to claim 24, further comprising:

monitoring the holographic material while the information is being recorded.

28. The method according to claim 19, further comprising:

deepening the position in the medium.

29. An apparatus comprising:

an irradiator, including an electromagnetic wave source which emits an electromagnetic wave, to irradiate a medium with the electromagnetic wave which is scattered in the medium;

a modulator to modulate a frequency of the electromagnetic wave at a position in the medium;

a detector to obtain information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and a reference wave, and

a generator to generate a phase conjugate wave, based on the obtained information, which irradiates the medium.

30. The apparatus according to claim 29, wherein the modulator comprises an ultrasonic device.

31. The apparatus according to claim 29, wherein the detector comprises a CCD sensor or a CMOS sensor.

32. The apparatus according to claim 29, wherein the generator comprises a spatial light modulator to form the phase conjugate wave.

33. The apparatus according to claim 29, wherein the apparatus is configured to combine an acousto-optic imaging system with a photo-acoustic imaging system.