US3767310A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffraction grating beam splitter
Assignee: International Business Machines Corp
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Filing: 1972-06-23
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Granted: 1973-10-23
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Expires: 1992-06-23
Abstract
Abstract The optical system divides a beam of coherent radiation into a pair of beams having powers according to a desired ratio. The primary beam is intercepted by a holographic diffraction grating positioned at approximately the Bragg angle, placing virtually all the diffracted energy into the 0th and the selected one of either the +1st or -1st diffraction orders. The ratio of the power of the 0th order to selected one of the +1st or -1st diffraction order is varied by changing the angle of the grating with respect to the primary beam. The ratio can be set by calibrating the angle of the grating in terms of the split ratio or by monitoring the power of the unselected one of the +1st or -1st diffraction order. The output signal from the power monitor in the unselected order can also be used to control the power of the primary beam.
Inventors
- 👤 Le Roy Dickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:55
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/1073; G02B27/108; G02B27/1086; G02B27/1093; G02B5/00; G02B5/32
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
106 words
Means for dividing a primary beam of coherent radiation into a pair of beams having power according to a predetermined ratio, said means comprising: a diffraction grating positioned to intercept said primary beam at an angle to place essentially all the energy affected by said grating into the 0th and the selected one of the +1st or 1st diffraction orders, and power monitoring means positioned to intercept the resulting beam in the unselected one of said +1st or -1st diffraction orders to provide an output signal representing the relative powers of the beams in the 0th and selected one of said +1st or -1st diffraction orders.
Claim 2
Dependent Claim
106 words
Means for dividing a primary beam of coherent radiation into a pair of beams having power according to a predetermined ratio, said means comprising: a diffraction grating positioned to intercept said primary beam at an angle to place essentially all the energy affected by said grating into the 0th and the selected one of the +1st or 1st diffraction orders, and power monitoring means positioned to intercept the resulting beam in the unselected one of said +1st or -1st diffraction orders to provide an output signal representing the relative powers of the beams in the 0th and selected one of said +1st or -1st diffraction orders.
Claim 3
Dependent Claim
16 words
A means according to claim 1 wherein said diffraction grating is a holographic phase diffraction grating.
Claim 4
Dependent Claim
10 words
measuring and recording the power of the 0th order beam,
Claim 5
Dependent Claim
10 words
measuring and recording the power of the 0th order beam,
Claim 6
Dependent Claim
10 words
measuring and recording the power of the 0th order beam,
Claim 7
Dependent Claim
10 words
measuring and recording the power of the 0th order beam,
Claim 8
Dependent Claim
16 words
measuring and recording the power of the selected one of the +1st or -1st diffraction order,
Claim 9
Dependent Claim
16 words
measuring and recording the power of the selected one of the +1st or -1st diffraction order,
Claim 10
Dependent Claim
10 words
measuring and recording the power of the +1st order beam,
Claim 11
Dependent Claim
10 words
measuring and recording the power of the +1st order beam,
Claim 12
Dependent Claim
14 words
A means according to claim 2 wherein the angle is approximately the Bragg angle.
Claim 13
Dependent Claim
141 words
Means for dividing a beam of coherent radiation into a pair of beams having powers controlled according to a predetermined ratio, said means comprising: a diffraction grating positioned to intercept said beam at an angle to place essentially all the energy affected by said grating into the 0th and the selected one of the +1st and the -1st diffraction orders, monitoring means positioned to intercept the resulting beam in the unselected one of said +1st or -1st diffraction orders to provide an output signal representing the power of said resulting beam, and positioning means responsive to said output signal for rotating the said diffraction grating to set the power of said unselected beam to a desired value whereby the power ratio of the 0th to the one other of said +1st and -1st diffraction orders is set to a desired value.
Claim 14
Dependent Claim
141 words
Means for dividing a beam of coherent radiation into a pair of beams having powers controlled according to a predetermined ratio, said means comprising: a diffraction grating positioned to intercept said beam at an angle to place essentially all the energy affected by said grating into the 0th and the selected one of the +1st and the -1st diffraction orders, monitoring means positioned to intercept the resulting beam in the unselected one of said +1st or -1st diffraction orders to provide an output signal representing the power of said resulting beam, and positioning means responsive to said output signal for rotating the said diffraction grating to set the power of said unselected beam to a desired value whereby the power ratio of the 0th to the one other of said +1st and -1st diffraction orders is set to a desired value.
Claim 15
Dependent Claim
15 words
calculating the split ratio of the power levels recorded in the steps 2 and 3,
Claim 16
Dependent Claim
15 words
calculating the split ratio of the power levels recorded in the steps 2 and 3,
Claim 17
Dependent Claim
10 words
measuring and recording the power of the -1st order beam,
Claim 18
Dependent Claim
10 words
measuring and recording the power of the -1st order beam,
Claim 19
Dependent Claim
15 words
repositioning the grating to a slightly different angle and repeating steps 2, 3 and 4,
Claim 20
Dependent Claim
15 words
repositioning the grating to a slightly different angle and repeating steps 2, 3 and 4,
Claim 21
Dependent Claim
12 words
measuring and recording the angle of said grating to the incident beam,
Claim 22
Dependent Claim
12 words
measuring and recording the angle of said grating to the incident beam,
Claim 23
Dependent Claim
124 words
In a system for dividing a beam of coherent radiation into a pair of beams having a desired power ratio, the combination comprising: a holographic Bragg phase diffraction grating positioned to intercept said beam at approximately the Bragg angle to place essentially all the non-absorbed energy affected by said grating into the 0th and the selected one of the +1st and -1st diffraction orders, means for rotating said grating to vary the angle at which the beam is incident on the grating, indicating means, coupled to said rotating means for representing the angular position of said grating, said indicating means having a scale calibrated according to the ratio of power of the 0th and the selected one of the +1st and -1st diffraction orders.
Claim 24
Dependent Claim
124 words
In a system for dividing a beam of coherent radiation into a pair of beams having a desired power ratio, the combination comprising: a holographic Bragg phase diffraction grating positioned to intercept said beam at approximately the Bragg angle to place essentially all the non-absorbed energy affected by said grating into the 0th and the selected one of the +1st and -1st diffraction orders, means for rotating said grating to vary the angle at which the beam is incident on the grating, indicating means, coupled to said rotating means for representing the angular position of said grating, said indicating means having a scale calibrated according to the ratio of power of the 0th and the selected one of the +1st and -1st diffraction orders.
Claim 25
Independent Claim
38 words
The method of calibrating a holographic Bragg phase diffraction grating in terms of the split ratios of power between the 0th diffraction order and the selected one of the +1st or -1st diffraction orders comprising the steps of:
Claim 26
Independent Claim
38 words
The method of calibrating a holographic Bragg phase diffraction grating in terms of the split ratios of power between the 0th diffraction order and the selected one of the +1st or -1st diffraction orders comprising the steps of:
Claim 27
Dependent Claim
31 words
repositioning the gratings to a slightly different angle and repeating steps 2 - 5 to develop a table of split ratios for grating angles in the range of the Bragg angle.
Claim 28
Dependent Claim
31 words
repositioning the gratings to a slightly different angle and repeating steps 2 - 5 to develop a table of split ratios for grating angles in the range of the Bragg angle.
Claim 29
Dependent Claim
43 words
repeating the preceding steps to provide sufficient measurements to calibrate the split ratio between the 0th order and the selected one of the +1st or -1st order in terms of the power of the unselected one of the +1st or the -1st order.
Claim 30
Dependent Claim
43 words
repeating the preceding steps to provide sufficient measurements to calibrate the split ratio between the 0th order and the selected one of the +1st or -1st order in terms of the power of the unselected one of the +1st or the -1st order.
Claim 31
Independent Claim
53 words
The method of calibrating a holographic Bragg phase diffraction grating in terms of the power of the unselected one of the +1st or -1st diffraction order and its relationship to the split ratio between the 0th diffraction order and the selected one of the +1st or -1st diffraction orders comprising the steps of:
Claim 32
Independent Claim
53 words
The method of calibrating a holographic Bragg phase diffraction grating in terms of the power of the unselected one of the +1st or -1st diffraction order and its relationship to the split ratio between the 0th diffraction order and the selected one of the +1st or -1st diffraction orders comprising the steps of:
Claim 33
Dependent Claim
170 words
In an optical system for dividing a primary beam of coherent radiation into a pair of beams, means for holding the power of said primary beam to a constant value comprising: a diffraction grating positioned to intercept said primary beam at an angle to place essentially all the energy affected by the grating into the 0th and the selected one of the +1st and -1st diffraction orders, monitoring means positioned to intercept the resulting beam in the unselected one of said +1st or -1st diffraction orders to provide an output signal representing the power of said beam, output power control means for varying the power of said primary beam in response to a signal applied to a control terminal, means connecting said output signal from said monitoring means to said control terminal whereby a change in the power in said primary beam results in a change in the output signal from said moNitoring means which is effective to restore the beam to the original power level through said control means.
Claim 34
Dependent Claim
170 words
In an optical system for dividing a primary beam of coherent radiation into a pair of beams, means for holding the power of said primary beam to a constant value comprising: a diffraction grating positioned to intercept said primary beam at an angle to place essentially all the energy affected by the grating into the 0th and the selected one of the +1st and -1st diffraction orders, monitoring means positioned to intercept the resulting beam in the unselected one of said +1st or -1st diffraction orders to provide an output signal representing the power of said beam, output power control means for varying the power of said primary beam in response to a signal applied to a control terminal, means connecting said output signal from said monitoring means to said control terminal whereby a change in the power in said primary beam results in a change in the output signal from said moNitoring means which is effective to restore the beam to the original power level through said control means.
Claim 35
Dependent Claim
23 words
A system according to claim 5 wherein said output power control means includes a power supply for the source of the primary beam.
Claim 36
Dependent Claim
21 words
A system according to claim 5 wherein said output power control means includes a modulator positioned to intercept said primary beam.
References Cited (Backward Citations)
US3611181A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |