Patent DE887278C successfully refreshed from Google Patents.
US4002403A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Suppressing superradiance
Assignee: Battelle Memorial Institute Inc
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Filing: 1973-10-11
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Granted: 1977-01-11
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Expires: 1993-10-11
Abstract
Abstract Methods and apparatus for directing a radiation pulse from a laser to a target or other selected location and preventing undesired earlier radiation from the laser having less than a selected intensity from reaching the selected location. A beam splitter directs a major portion of the radiation pulse energy along a longer main path to a predetermined region and continuing on toward the selected location, and directs a minor portion along a shorter secondary path to the predetermined region. A reflective surface on a transparent support in the predetermined region prevents energy having less than the selected intensity from continuing on toward the selected location. The surface comprises a thin layer, as of aluminum, that remains substantially unimpaired until it is subjected to radiation having at least the selected itensity, and then is substantially removed in the area impinged by such radiation, so that when the minor portion of the radiation pulse energy along the shorter secondary path has at least the selected intensity, and thus substantially removes the impinged area of the reflective layer, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the area of removal toward the selected location. Alternatively, the minor energy portion actuates an electrical discharge to vaporize the reflective layer at least substantially.
Inventors
- 👤 Philip J. Mallozzi
- 👤 Harold M. Epstein
- 👤 David C. Applebaum
- 👤 William J. Gallagher
- 👤 Bernerd E. Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:20
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/005
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
192 words
A method of directing a radiation pulse from a source to a selected location and preventing undesired earlier radiation from the source having less than a selected intensity from reaching the selected location, comprising directing a major portion of the radiation pulse energy along a main path to a predetermined region and continuing on toward the selected location, positioning a reflective surface comprising a thin reflective layer in the predetermined region to prevent energy impinging thereon from continuing on toward the selected location, directing a minor portion of the radiation pulse energy along a secondary path, and using the energy of the minor portion to actuate a substantial removal of the reflective layer in the predetermined region when the minor portion has the selected intensity and before the corresponding major portion of the radiation pulse reaches the predetermined region, so that when the minor portion of the radiation pulse energy along the secondary path has at least the selected intensity, and thus causes the reflective layer to be substantially removed, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the region toward the selected location.
Claim 2
Independent Claim
192 words
A method of directing a radiation pulse from a source to a selected location and preventing undesired earlier radiation from the source having less than a selected intensity from reaching the selected location, comprising directing a major portion of the radiation pulse energy along a main path to a predetermined region and continuing on toward the selected location, positioning a reflective surface comprising a thin reflective layer in the predetermined region to prevent energy impinging thereon from continuing on toward the selected location, directing a minor portion of the radiation pulse energy along a secondary path, and using the energy of the minor portion to actuate a substantial removal of the reflective layer in the predetermined region when the minor portion has the selected intensity and before the corresponding major portion of the radiation pulse reaches the predetermined region, so that when the minor portion of the radiation pulse energy along the secondary path has at least the selected intensity, and thus causes the reflective layer to be substantially removed, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the region toward the selected location.
Claim 3
Dependent Claim
26 words
A method as in claim 1, wherein the minor portion of the pulse energy is about 10 to 40 percent of the total radiation pulse energy.
Claim 4
Dependent Claim
32 words
A method as in claim 1, comprising the further step of moving the reflective surface afterward to locate an intact area thereof at the predetermined region, and then repeating the other steps.
Claim 5
Dependent Claim
23 words
A method as in claim 1, wherein the minor energy portion actuates an electrical discharge to vaporize the reflective layer at least substantially.
Claim 6
Dependent Claim
69 words
A method as in claim 1, wherein the minor energy portion is directed along the secondary path to reach the predetermined region before the corresponding major portion of the radiation pulse reaches it, and the thin reflective layer comprises a material that remains substantially unimpaired until it is subjected to radiation having at least the selected intensity, and then is substantially removed in the area impinged by such radiation.
Claim 7
Independent Claim
194 words
A method of directing a radiation pulse from a source to a selected location and preventing undesired earlier radiation from the source having less than a selected intensity from reaching the selected location, comprising directing a major portion of the radiation pulse energy along a longer main path to a predetermined region and continuing on toward the selected location, directing a minor portion of the radiation pulse energy along a shorter secondary path to the predetermined region, and positioning a reflective surface in the predetermined region to prevent energy having less than the selected intensity from continuing on toward the selected location, the surface comprising a thin reflective layer that remains substantially unimpaired until it is subjected to radiation having at least the selected intensity, and then is substantially removed in the area impinged by such radiation, so that when the minor portion of the radiation pulse energy along the shorter secondary path has at least the selected intensity, and thus substantially removes the impinged area of the reflective layer, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the area of removal toward the selected location.
Claim 8
Independent Claim
194 words
A method of directing a radiation pulse from a source to a selected location and preventing undesired earlier radiation from the source having less than a selected intensity from reaching the selected location, comprising directing a major portion of the radiation pulse energy along a longer main path to a predetermined region and continuing on toward the selected location, directing a minor portion of the radiation pulse energy along a shorter secondary path to the predetermined region, and positioning a reflective surface in the predetermined region to prevent energy having less than the selected intensity from continuing on toward the selected location, the surface comprising a thin reflective layer that remains substantially unimpaired until it is subjected to radiation having at least the selected intensity, and then is substantially removed in the area impinged by such radiation, so that when the minor portion of the radiation pulse energy along the shorter secondary path has at least the selected intensity, and thus substantially removes the impinged area of the reflective layer, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the area of removal toward the selected location.
Claim 9
Dependent Claim
213 words
In an apparatus for directing a radiation pulse from a source therein to a selected location therein and preventing undesired earlier radiation from the source having less than a selected intensity from reaching the selected location, the improvement comprising means for directing a major portion of the radiation pulse energy along a main path to a predetermined region and continuing on toward the selected location, reflective surface means comprising a thin reflective layer in the predetermined region to prevent energy impinging thereon from continuing on toward the selected location, means for directing a minor portion of the radiation pulse energy along a secondary path, and means in the secondary path responsive to radiation having at least the selected intensity positioned to receive the minor portion of the radiation pulse and to substantially remove the reflective layer in the predetermined region in response to the selected intensity thereof before the corresponding major portion of the radiation pulse reaches the predetermined region, so that when the minor portion of the radiation pulse energy along the secondary path has at least the selected intensity, and thus causes the reflective layer to be substantially removed, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the region toward the selected location.
Claim 10
Dependent Claim
213 words
In an apparatus for directing a radiation pulse from a source therein to a selected location therein and preventing undesired earlier radiation from the source having less than a selected intensity from reaching the selected location, the improvement comprising means for directing a major portion of the radiation pulse energy along a main path to a predetermined region and continuing on toward the selected location, reflective surface means comprising a thin reflective layer in the predetermined region to prevent energy impinging thereon from continuing on toward the selected location, means for directing a minor portion of the radiation pulse energy along a secondary path, and means in the secondary path responsive to radiation having at least the selected intensity positioned to receive the minor portion of the radiation pulse and to substantially remove the reflective layer in the predetermined region in response to the selected intensity thereof before the corresponding major portion of the radiation pulse reaches the predetermined region, so that when the minor portion of the radiation pulse energy along the secondary path has at least the selected intensity, and thus causes the reflective layer to be substantially removed, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the region toward the selected location.
Claim 11
Dependent Claim
203 words
In an apparatus for directing a radiation pulse from a source therein to a selected location therein and preventing undesired earlier radiation from the source having less than a selected intensity from reaching the selected location, the improvement comprising means for directing a major portion of the radiation pulse energy along a longer main path to a predetermined region and continuing on toward the selected location, means for directing a minor portion of the radiation pulse energy along a shorter secondary path to the predetermined region, and reflective surface means in the predetermined region to prevent energy having less than the selected intensity from continuing on toward the selected location, the surface means comprising a thin reflective layer that remains substantially unimpaired until it is subjected to radiation having at least the selected intensity, and then is substantially removed in the area impinged by such radiation, so that when the minor portion of the radiation pulse energy along the shorter secondary path has at least the selected intensity, and thus substantially removes the impinged area of the reflective layer, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the area of removal toward the selected location.
Claim 12
Dependent Claim
203 words
In an apparatus for directing a radiation pulse from a source therein to a selected location therein and preventing undesired earlier radiation from the source having less than a selected intensity from reaching the selected location, the improvement comprising means for directing a major portion of the radiation pulse energy along a longer main path to a predetermined region and continuing on toward the selected location, means for directing a minor portion of the radiation pulse energy along a shorter secondary path to the predetermined region, and reflective surface means in the predetermined region to prevent energy having less than the selected intensity from continuing on toward the selected location, the surface means comprising a thin reflective layer that remains substantially unimpaired until it is subjected to radiation having at least the selected intensity, and then is substantially removed in the area impinged by such radiation, so that when the minor portion of the radiation pulse energy along the shorter secondary path has at least the selected intensity, and thus substantially removes the impinged area of the reflective layer, the major portion of the radiation pulse reaching the predetermined region thereafter can continue on through the area of removal toward the selected location.
Claim 13
Dependent Claim
40 words
Apparatus as in claim 8, wherein the reflective surface means is positioned so as to reflect the undesired earlier radiation in a direction that avoids contact with any portion of the apparatus that might be adversely affected by such radiation.
Claim 14
Dependent Claim
32 words
Apparatus as in claim 9, wherein the reflective surface means is positioned at an angle of about 2° to 30° from a plane normal to the main path at the predetermined region.
Claim 15
Dependent Claim
17 words
Apparatus as in claim 8, wherein the reflective layer comprises essentially aluminum, gold, silver, copper, or lead.
Claim 16
Dependent Claim
16 words
Apparatus as in claim 11, wherein the reflective layer is about 100 to 1000 angstroms thick.
Claim 17
Dependent Claim
16 words
Apparatus as in claim 12, wherein the reflective layer comprises a coating on a transparent support.
Claim 18
Dependent Claim
18 words
Apparatus as in claim 13, wherein the support comprises essentially glass, quartz, polyethylene terephthalate, or other transparent plastic.
Claim 19
Dependent Claim
15 words
Apparatus as in claim 14, wherein the support is less than about 10 wavelengths thick.
Claim 20
Dependent Claim
35 words
Apparatus as in claim 8, wherein the radiation source is a neodymium laser, and the reflective layer comprises a coating consisting essentially of aluminum about 100 to 1000 angstroms thick on a polyethylene terephthalate support.
Claim 21
Dependent Claim
18 words
Apparatus as in claim 16, wherein the selected intensity is about 0.2 to 2 joules per square centimeter.
Claim 22
Dependent Claim
22 words
Apparatus as in claim 8, wherein the radiation source comprises a laser that may emit other radiation before a stimulated emission pulse.
Claim 23
Dependent Claim
24 words
Apparatus as in claim 8, wherein the means for directing the major and minor portions of the radiation pulse energy comprises a beam splitter.
Claim 24
Dependent Claim
28 words
Apparatus as in claim 19, further comprising means for moving the beam splitter to control the ratio of the major portion to the minor portion of the energy.
Claim 25
Dependent Claim
32 words
Apparatus as in claim 20, wherein the beam splitter is adjusted to direct about 10 to 40 percent of the energy along the shorter path and the balance along the longer path.
Claim 26
Dependent Claim
14 words
Apparatus as in claim 8, comprising at least one reflector in the longer path.
Claim 27
Dependent Claim
16 words
Apparatus as in claim 8, comprising also means for adjusting the length of the longer path.
Claim 28
Dependent Claim
22 words
Apparatus as in claim 23, wherein the adjusting means comprises a reflector in the longer path and means for controlling its position.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-11 | 1980-07-12 | 1981-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-11 | 1984-07-12 | 1985-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-11 | 1988-07-12 | 1989-01-11 | $7700.00 | Window Closed / Lapsed |