Patent US6037579A successfully refreshed from Google Patents.
US6037579A
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US
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Optical interferometer employing multiple detectors to detect spatially distorted wavefront in imaging of scattering media
Assignee: BIOPHOTONICS INFORMATION LABORATORIES Ltd
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Filing: 1998-03-16
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Granted: 2000-03-14
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Expires: 2018-03-16
Abstract
Abstract There is disclosed an optical measurement device which is based on optical interference and it uses a light beam which is radiated to and transmitted through or reflected by a sample, especially a light scattering medium to optically measure the sample. The amount of signal lights effective for optical heterodyne detection is increased, while speckle noises are averaged out. On an observation plane of a concerned point arranged are plural detector elements. From signals obtained by the respective detector elements, an optical signal of the concerned point is obtained.
Inventors
- 👤 Kinpui Chan
- 👤 Koji Satori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:36
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/4795
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
239 words
An optical interferometer apparatus having spatially resolved detection capability to detect a spatially distorted wavefront of a light beam collected from a scattering media comprising: a light source for emitting a light beam; a beam splitter for splitting the light beam emitted from said light source into a first partial beam which is guided into an object arm of said optical interferometer apparatus and is then incident to a measured object which is disposed at a position along said object arm, and a second partial beam which is guided into a reference arm of said optical interferometer apparatus; a collecting lens adapted for collecting light emerging from a point either on a surface of or an inside of said measured object to provide a signal light beam; a recombining beam splitter for superimposing said signal light beam onto said second partial beam to provide a resultant interference light beam; a photo detector array configuration having a plurality of spatially arranged detector elements to produce a plurality of detector signal outputs which are position sensitive to a wavefront and intensity distribution of said resultant interference light beam; and a signal processing unit for summing amplitudes of said plural detector signal outputs to produce a single point data having an amplitude that is regarded as being proportional to an intensity of said signal light beam collected from said point either on the surface of or the inside of said measured object.
Claim 2
Dependent Claim
239 words
An optical interferometer apparatus having spatially resolved detection capability to detect a spatially distorted wavefront of a light beam collected from a scattering media comprising: a light source for emitting a light beam; a beam splitter for splitting the light beam emitted from said light source into a first partial beam which is guided into an object arm of said optical interferometer apparatus and is then incident to a measured object which is disposed at a position along said object arm, and a second partial beam which is guided into a reference arm of said optical interferometer apparatus; a collecting lens adapted for collecting light emerging from a point either on a surface of or an inside of said measured object to provide a signal light beam; a recombining beam splitter for superimposing said signal light beam onto said second partial beam to provide a resultant interference light beam; a photo detector array configuration having a plurality of spatially arranged detector elements to produce a plurality of detector signal outputs which are position sensitive to a wavefront and intensity distribution of said resultant interference light beam; and a signal processing unit for summing amplitudes of said plural detector signal outputs to produce a single point data having an amplitude that is regarded as being proportional to an intensity of said signal light beam collected from said point either on the surface of or the inside of said measured object.
Claim 3
Dependent Claim
21 words
The optical apparatus according to claim 1, wherein said object arm and said reference arm are parts of a Mach-Zehnder interferometer.
Claim 4
Dependent Claim
16 words
The optical apparatus according to claim 1, wherein said light source comprises a continuous wave laser.
Claim 5
Dependent Claim
23 words
The optical apparatus according to claim 1, wherein said light source comprises a continuous wave laser having a frequency that is periodically modulated.
Claim 6
Dependent Claim
42 words
The optical apparatus according to claim 1, wherein said light source comprises a light source having a short coherence length chosen from a group comprising a light emitting diode, a super luminescent diode, a femtosecond pulsed laser, and a gas discharge lamp.
Claim 7
Dependent Claim
15 words
The optical apparatus according to claim 1, wherein said light source comprises a pulsed laser.
Claim 8
Dependent Claim
34 words
The optical apparatus according to claim 1, further comprising a frequency difference imparting device for generating a frequency difference between the first partial light beam and the second partial light beam of said apparatus.
Claim 9
Dependent Claim
21 words
The optical apparatus according to claim 7, wherein said frequency difference imparting device comprises at least one or more acousto-optic modulators.
Claim 10
Dependent Claim
22 words
The optical apparatus according to claim 8, wherein said frequency difference imparting device comprises at least one or more electro-optic phase modulators.
Claim 11
Dependent Claim
17 words
The optical apparatus according to claim 8, wherein said frequency difference imparting device comprises a piezoelectric element.
Claim 12
Dependent Claim
45 words
The optical apparatus according the claim 1, further comprising a scanning mechanism which one-dimensionally or two-dimensionally moves at least one of the measured object and the first partial light beam in said object arm to scan said measured object with said first partial light beam.
Claim 13
Dependent Claim
31 words
The optical apparatus according to claim 1, further comprising a rotation mechanism that rotates at least one of the measured object and the first partial light beam in said object arm.
Claim 14
Dependent Claim
50 words
The optical apparatus according to claim 1, further comprising a pair of lenses disposed in the object arm for transmitting said signal light beam collected by said collecting lens to said recombining beam splitter, and an aperture disposed on a Fourier plane of the pair of lenses for spatial filtering.
Claim 15
Dependent Claim
27 words
The optical apparatus according to claim 1, wherein said signal processing unit rectifies and sums up said plurality of detector signal outputs from said photo detector array.
Claim 16
Dependent Claim
31 words
The optical apparatus according to claim 1, wherein said signal processing unit performs phase matching for said plural detector signal outputs from said photo detector array, and sums up their amplitudes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-03-14 | 2003-09-13 | 2004-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-03-14 | 2007-09-13 | 2008-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-03-14 | 2011-09-13 | 2012-03-14 | $7700.00 | Window Closed / Lapsed |