Patent US5633711A successfully refreshed from Google Patents.
US5633711A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measurement of material properties with optically induced phonons
Assignee: Massachusetts Institute of Technology
•
Filing: 1994-12-05
•
Granted: 1997-05-27
•
Expires: 2014-12-05
Abstract
Abstract Samples such as thin polymeric films are analyzed using optically induced phonons by excitation of the sample using radiation preferably absorbed by the sample and probe radiation, preferably not absorbed by the sample, that is diffracted from the surface of the sample. The pulse width of the probe is preferably on the order of the detectable diffraction signal so that the phonon decay from each excitation pulse can be detected and analyzed. The technique is applicable to various samples by inducing a ripple morphology on the sample surface and detection of light diffracted substantially from surface ripple.
Inventors
- 👤 Keith A. Nelson
- 👤 Anil R. Duggal
- 👤 John A. Rogers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:20
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/02; G01B11/06; G01B11/0616; G01B11/0666; G01B11/0675; G01N; G01N21/00; G01N21/17; G01N21/1717; G01N21/62; G01N21/63; G01N21/636; G01N29/00; G01N29/22; G01N29/24; G01N29/2418; G01N2291/00; G01N2291/02; G01N2291/023; G01N2291/0235; G01N2291/028; G01N2291/02827; G01N2291/04; G01N2291/042; G01N2291/0422; G01N2291/0423; G01N33/00; G01N33/44
Claims Analysis
Total Claims: 61
Claim 1
Independent Claim
171 words
An apparatus for measuring the properties of a sample of material, comprising: a first, excitation source for producing excitation radiation adapted to impinge upon said sample of material, said excitation radiation comprising radiation composed of at least two component beams which interfere within said sample, each incidence of interference of said excitation radiation being sufficient to induce transient phonons in said material which give rise to a transient, time dependent periodic ripple morphology of alternating peaks and valleys on a surface of said sample, a detection system for detecting said ripple morphology by diffraction of radiation including: a second, probe source for producing probe radiation arranged to be diffracted by the periodic ripple morphology on the surface of said sample to form a diffraction signal which emerges on the same side of said sample as said probe radiation, a detector for detecting the diffraction signal from said probe source radiation diffracted by said surface ripple morphology, and an analyzer for selectively analyzing said diffraction signal formed by said transient ripple morphology.
Claim 2
Independent Claim
171 words
An apparatus for measuring the properties of a sample of material, comprising: a first, excitation source for producing excitation radiation adapted to impinge upon said sample of material, said excitation radiation comprising radiation composed of at least two component beams which interfere within said sample, each incidence of interference of said excitation radiation being sufficient to induce transient phonons in said material which give rise to a transient, time dependent periodic ripple morphology of alternating peaks and valleys on a surface of said sample, a detection system for detecting said ripple morphology by diffraction of radiation including: a second, probe source for producing probe radiation arranged to be diffracted by the periodic ripple morphology on the surface of said sample to form a diffraction signal which emerges on the same side of said sample as said probe radiation, a detector for detecting the diffraction signal from said probe source radiation diffracted by said surface ripple morphology, and an analyzer for selectively analyzing said diffraction signal formed by said transient ripple morphology.
Claim 3
Dependent Claim
19 words
The apparatus of claim 1 wherein said probe source produces radiation that is not substantially absorbed by said sample.
Claim 4
Dependent Claim
25 words
The apparatus of claim 1 wherein said probe source produces radiation that is absorbed about 10% or less than said radiation from said excitation source.
Claim 5
Dependent Claim
25 words
The apparatus of claim 3 wherein said probe source produces radiation that is absorbed about 1% or less than said radiation from said excitation source.
Claim 6
Dependent Claim
30 words
The apparatus of claim 1 wherein said excitation source radiation comprises ultraviolet radiation absorbed sufficiently by said sample to induce heating that gives rise to said phonons and ripple morphology.
Claim 7
Dependent Claim
19 words
The apparatus of claim 5 wherein said probe source radiation comprises visible radiation not substantially absorbed by said sample.
Claim 8
Dependent Claim
18 words
The apparatus of claim 1 wherein said sample comprises a thin sample of about 500 μm or less.
Claim 9
Dependent Claim
15 words
The apparatus of claim 7 wherein said thin sample is about 10 μm or less.
Claim 10
Dependent Claim
13 words
The apparatus of claim 1 wherein said sample comprises a thin polymeric film.
Claim 11
Dependent Claim
12 words
The apparatus of claim 9 wherein said film comprises a free-standing film.
Claim 12
Dependent Claim
13 words
The apparatus of claim 9 where said film is disposed on a support.
Claim 13
Dependent Claim
33 words
The apparatus of claim 1 wherein said analyzer includes a polarizer for determining change of polarization of said probe beam after diffraction from said surface to selectively analyze diffraction from said ripple morphology.
Claim 14
Dependent Claim
29 words
The apparatus of claim 1 wherein said analyzer is for analyzing said signal as a function of the wavevector and to selectively analyze diffraction signal from said ripple morphology.
Claim 15
Dependent Claim
34 words
The apparatus of claim 1 further including a probe beam and detector constructed for detecting and resolving a substantial time-portion of the time-dependent diffraction induced by each incidence of interference of said excitation radiation.
Claim 16
Dependent Claim
39 words
The apparatus of claim 14 wherein said excitation radiation is pulsed radiation and, said probe radiation is of a selected pulse width and said detector is adapted to detect the diffraction signal for the duration of said probe pulse.
Claim 17
Dependent Claim
22 words
The apparatus of claim 15 wherein said detector is constructed to detect the entire detectable diffraction signal induced by each excitation pulse.
Claim 18
Dependent Claim
32 words
The apparatus of claim 16 wherein said excitation radiation has a pulse width on the order of psec duration and the probe radiation pulse width is on the order of nsec duration.
Claim 19
Dependent Claim
18 words
The apparatus of claim 17 wherein said detector has a time resolution on the order of 1 nsec.
Claim 20
Dependent Claim
20 words
The apparatus of claim 14 wherein said probe pulse has a peak power output of about 1000 watts or greater.
Claim 21
Dependent Claim
13 words
The apparatus of claim 19 wherein said laser comprises a Q-switch YAG laser.
Claim 22
Dependent Claim
25 words
The apparatus of claim 14 wherein said excitation pulse is generated from a pulsed laser and said probe pulse is generated from a CW laser.
Claim 23
Dependent Claim
24 words
The apparatus of claim 1 including an analyzer adapted for determining from said diffraction signal the adhesion of said sample on a substrate surface.
Claim 24
Dependent Claim
30 words
The apparatus of claim 1, wherein the sample of material is a thin film, and the analyzer selectively analyzes the diffraction signal to determine the thickness of the thin film.
Claim 25
Dependent Claim
15 words
The apparatus of claim 23, wherein the thin film is opaque to the excitation radiation.
Claim 26
Independent Claim
121 words
A method for measuring the properties of a sample comprising: impinging a pulse of excitation radiation upon said sample, said excitation radiation being composed of at least two component beams which interfere within said sample, and being selected such that each incidence of said interference is sufficient to induce transient phonons in said sample which give rise to a transient, time dependent ripple morphology of alternating peaks and valleys on a surface of said sample, detecting said ripple morphology by diffraction of probe radiation from said surface having the periodic ripple morphology to form a diffraction signal which emerges on the same side of said sample as said probe radiation, and selectively detecting the diffraction signal diffracted by said ripple morphology.
Claim 27
Independent Claim
121 words
A method for measuring the properties of a sample comprising: impinging a pulse of excitation radiation upon said sample, said excitation radiation being composed of at least two component beams which interfere within said sample, and being selected such that each incidence of said interference is sufficient to induce transient phonons in said sample which give rise to a transient, time dependent ripple morphology of alternating peaks and valleys on a surface of said sample, detecting said ripple morphology by diffraction of probe radiation from said surface having the periodic ripple morphology to form a diffraction signal which emerges on the same side of said sample as said probe radiation, and selectively detecting the diffraction signal diffracted by said ripple morphology.
Claim 28
Dependent Claim
15 words
The method of claim 25 wherein said sample is about 500 μm thick or less.
Claim 29
Dependent Claim
15 words
The method of claim 26 wherein said sample is about 10 μm thick or less.
Claim 30
Dependent Claim
13 words
The method of claim 27 wherein said sample is a pure polymer sample.
Claim 31
Dependent Claim
15 words
The method of claim 28 comprising selecting excitation radiation that is absorbed by the sample.
Claim 32
Dependent Claim
17 words
The method of claim 29 comprising selecting probe radiation that is absorbed less than said excitation radiation.
Claim 33
Dependent Claim
17 words
The method of claim 30 comprising selecting probe radiation that is not substantially absorbed by said sample.
Claim 34
Dependent Claim
19 words
The method of claim 31 wherein said excitation radiation comprises UV radiation and said probe radiation comprises visible radiation.
Claim 35
Dependent Claim
26 words
The method of claim 25 comprising detecting and resolving a substantial time-portion of the diffraction signal induced by each incidence of interference of said excitation radiation.
Claim 36
Dependent Claim
13 words
The method of claim 33 wherein said probe source is a CW laser.
Claim 37
Dependent Claim
38 words
The method of claim 33 further comprising: providing a probe source having a peak power output of about 1000 watts or greater, and detecting and resolving a substantial time-portion of the time-dependent diffraction induced by each excitation pulse.
Claim 38
Dependent Claim
16 words
The method of claim 33 further including signal averaging the diffracted radiation from multiple excitation pluses.
Claim 39
Dependent Claim
17 words
The method of claim 25 further comprising analyzing said signal to selectively analyze diffraction from said ripple.
Claim 40
Dependent Claim
13 words
The method of claim 35 comprising analyzing the polarization of said diffracted radiation.
Claim 41
Dependent Claim
15 words
The method of claim 37 comprising analyzing the diffracted radiation as a function of wavevector.
Claim 42
Independent Claim
27 words
The method of any one of claims 36 to 38 including optimizing the diffraction from said ripple by varying the angle of incidence of said probe beam.
Claim 43
Independent Claim
29 words
The method of any one of claims 36 to 38 including optimizing the diffraction from said ripple by varying the wavelength or angle of incidence of said excitation radiation.
Claim 44
Dependent Claim
21 words
The method of claim 25 further comprising determining from said diffraction signal the adhesion of said sample on a substrate surface.
Claim 45
Dependent Claim
33 words
The method of claim 37, wherein the sample of material is a thin film, and during the analyzing step the diffraction signal is selectively analyzed to determine the thickness of the thin film.
Claim 46
Dependent Claim
15 words
The method of claim 43, wherein the thin film is opaque to the excitation radiation.
Claim 47
Independent Claim
157 words
An apparatus for measuring the properties of a thin sample of polymeric material comprising: a first, excitation laser source for producing a pulse of radiation adapted to impinge upon said sample, said excitation source comprising radiation composed of at least two component pulses which interfere within said thin film, said excitation radiation adapted to induce transient phonons in said material which give rise to a transient, time-dependent periodic ripple morphology of alternating peaks and valleys on a surface of said sample, a detection system for detecting said ripple morphology by diffraction of radiation including: a second, probe laser source for producing radiation, said probe radiation being of selected wavelength not substantially absorbed by said sample and arranged to be diffracted by the periodic ripple morphology on the surface of said sample to form a diffraction signal which emerges on the same side of said sample as said probe radiation, and a detector for detecting the diffraction signal.
Claim 48
Independent Claim
157 words
An apparatus for measuring the properties of a thin sample of polymeric material comprising: a first, excitation laser source for producing a pulse of radiation adapted to impinge upon said sample, said excitation source comprising radiation composed of at least two component pulses which interfere within said thin film, said excitation radiation adapted to induce transient phonons in said material which give rise to a transient, time-dependent periodic ripple morphology of alternating peaks and valleys on a surface of said sample, a detection system for detecting said ripple morphology by diffraction of radiation including: a second, probe laser source for producing radiation, said probe radiation being of selected wavelength not substantially absorbed by said sample and arranged to be diffracted by the periodic ripple morphology on the surface of said sample to form a diffraction signal which emerges on the same side of said sample as said probe radiation, and a detector for detecting the diffraction signal.
Claim 49
Dependent Claim
29 words
The apparatus of claim 45 further including a probe beam and detector constructed for detecting and resolving a substantial time-portion of the time-dependent diffraction induced by each excitation pulse.
Claim 50
Dependent Claim
25 words
The apparatus of claim 46 further including a signal averager for signal averaging said diffraction signals arising from repeated excitation and probing of said sample.
Claim 51
Dependent Claim
31 words
The apparatus of claim 46 wherein said excitation pulse is on the order of psec duration and the probe is pulsed radiation with a pulse on the order of nsec duration.
Claim 52
Dependent Claim
18 words
The apparatus of claim 48 wherein the probe laser source peak power is about 1000 watts or more.
Claim 53
Dependent Claim
13 words
The apparatus of claim 49 wherein the peak power is about 10,000 watts.
Claim 54
Dependent Claim
13 words
The apparatus of claim 49 wherein said laser is a YAG Q-switched laser.
Claim 55
Dependent Claim
18 words
The apparatus of claim 51 wherein said detector has a response time on the order of 1 nsec.
Claim 56
Dependent Claim
22 words
The apparatus of claim 45 wherein said diffracted radiation is reflected from the back surface of said sample opposite said radiation sources.
Claim 57
Dependent Claim
13 words
The apparatus of claim 45 wherein said probe source is a CW laser.
Claim 58
Dependent Claim
15 words
The apparatus of claim 54 wherein said probe source is a gated argon ion laser.
Claim 59
Independent Claim
21 words
The apparatus of any one of claims 45 or 54 wherein said probe has a power output of around 1 watt.
Claim 60
Dependent Claim
25 words
The apparatus of claim 45 including an analyzer adapted for determining the adhesion of said polymer sample on a substrate surface from said diffraction signal.
Claim 61
Dependent Claim
21 words
The apparatus of claim 45 including an analyzer adapted for determining the thermal diffusion of said sample from said diffraction signal.
References Cited (Backward Citations)
US4522510A
Cited
US4728165A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-05-26 | 2000-11-25 | 2001-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-05-26 | 2004-11-25 | 2005-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-05-26 | 2008-11-25 | 2009-05-27 | $7700.00 | Window Closed / Lapsed |