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US4675872A
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Driver unit for a laser Q-switch
Assignee: Harris Corp
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Filing: 1985-09-30
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Granted: 1987-06-23
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Expires: 2005-09-30
Abstract
Abstract A Q-switch driver for controlling laser output pulses, so that the laser output pulses are of an approximately equal amplitude. Sequences of light request pulses, each such light request pulse for causing the laser to produce a laser output pulse, are input to the Q-switch driver. The Q-switch is controlled by an RF oscillating signal produced by the Q-switch driver such that when the RF signal is present there is no output signal from the laser, and when the RF signal is zero a laser output pulse is produced. If the time between sequences of light request pulses is greater than a predetermined value, the RF signal from the Q-switch driver is modified by leaving the RF partially on so that there is some Q-spoiling present. The amount of RF produced during each light request pulse is gradually diminished exponentially over a predetermined time so that eventually the RF goes to zero during each light request pulse. Modifying the RF produced by the Q-switch driver prevents the generation of a giant first pulse by the laser.
Inventors
- 👤 Marc H. Popek
- 👤 Kenneth D. Springer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:13
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/11; H01S3/1123; H01S3/115
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
41 words
A driver unit for controlling a laser Q-switch such that laser output pulses have an approximately equal amplitude, wherein when there have not been laser output pulses for a predetermined time said driver unit provides a predetermined amount of adjustable Q-spoiling.
Claim 2
Dependent Claim
41 words
A driver unit for controlling a laser Q-switch such that laser output pulses have an approximately equal amplitude, wherein when there have not been laser output pulses for a predetermined time said driver unit provides a predetermined amount of adjustable Q-spoiling.
Claim 3
Dependent Claim
23 words
The driver unit of claim 1 wherein the Q-spoiling decreases exponentially with each laser output pulse, and is provided for a predetermined time.
Claim 4
Dependent Claim
17 words
The driver unit of claim 2 wherein the rate of exponential decrease of the Q-spoiling is adjustable.
Claim 5
Dependent Claim
22 words
The driver unit means of claim 1 wherein the predetermined time during which there have been no laser output pulses is adjustable.
Claim 6
Dependent Claim
77 words
A driver unit means for controlling a laser Q-switch such that laser output pulses have an approximately equal amplitude, means for providing a light request pulse when a laser output pulse is required, wherein each light-request pulse is provided as an input to said driver unit means, and when the laser has not produced a laser output pulse for a predetermined time, said driver unit means provides a predetermined amount of adjustable Q-spoiling for a predetermined time.
Claim 7
Dependent Claim
77 words
A driver unit means for controlling a laser Q-switch such that laser output pulses have an approximately equal amplitude, means for providing a light request pulse when a laser output pulse is required, wherein each light-request pulse is provided as an input to said driver unit means, and when the laser has not produced a laser output pulse for a predetermined time, said driver unit means provides a predetermined amount of adjustable Q-spoiling for a predetermined time.
Claim 8
Dependent Claim
18 words
The driver unit of claim 5 wherein the amount of Q-spoiling decreases exponentially with each laser output pulse.
Claim 9
Dependent Claim
17 words
The driver unit of claim 6 wherein the rate of exponential decrease of the Q-spoiling is adjustable.
Claim 10
Dependent Claim
22 words
The driver unit means of claim 5 wherein the predetermined time during which there have been no laser output pulses is adjustable.
Claim 11
Dependent Claim
129 words
A driver unit means for controlling an acousto-optic laser Q-switch, comprising: means for providing light-request pulses when a laser output pulse is required, means for producing a control signal in response to said light-request pulses and for determining the time since a last light-request pulse; means for providing an RF signal; and means for producing a modified RF signal in response to said control and RF signals wherein said modified RF signal has a substantially constant amplitude between light-request pulses, and when there has not been a light-request pulse for a predetermined time said modified signal has an exponentially decaying envelope during successive light-request pulses; and wherein said modified RF signal is applied to the acousto-optic laser Q-switch such that the laser output pulses are of approximately equal amplitude.
Claim 12
Dependent Claim
129 words
A driver unit means for controlling an acousto-optic laser Q-switch, comprising: means for providing light-request pulses when a laser output pulse is required, means for producing a control signal in response to said light-request pulses and for determining the time since a last light-request pulse; means for providing an RF signal; and means for producing a modified RF signal in response to said control and RF signals wherein said modified RF signal has a substantially constant amplitude between light-request pulses, and when there has not been a light-request pulse for a predetermined time said modified signal has an exponentially decaying envelope during successive light-request pulses; and wherein said modified RF signal is applied to the acousto-optic laser Q-switch such that the laser output pulses are of approximately equal amplitude.
Claim 13
Dependent Claim
15 words
The driver unit means of claim 9 wherein the rate of exponential decay is adjustable.
Claim 14
Dependent Claim
18 words
The driver unit means of claim 9 wherein the initial valve of the exponentially decaying envelope is adjustable.
Claim 15
Dependent Claim
22 words
The driver unit means of claim 9 wherein the predetermined time during which there have been no laser output pulses is adjustable.
Claim 16
Dependent Claim
40 words
A driver unit means for controlling a laser Q-switch comprising means for producing laser output pulses having an approximately equal amplitude, and when not driving the Q-switch for a predetermined time means for providing a predetermined amount of adjustable Q-spoiling.
Claim 17
Dependent Claim
40 words
A driver unit means for controlling a laser Q-switch comprising means for producing laser output pulses having an approximately equal amplitude, and when not driving the Q-switch for a predetermined time means for providing a predetermined amount of adjustable Q-spoiling.
Claim 18
Dependent Claim
19 words
The driver unit means of claim 13 wherein the amount of Q-spoiling decreases exponentially with each laser output pulse.
Claim 19
Dependent Claim
18 words
The driver unit means of claim 13 wherein the rate of exponential decrease of the Q-spoiling is adjustable.
Claim 20
Dependent Claim
22 words
The driver unit means of claim 13 wherein the predetermined time during which there have been no laser output pulses is adjustable.
References Cited (Backward Citations)
US3673504A
Cited
US3747019A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-22 | 1990-12-22 | 1991-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-22 | 1994-12-22 | 1995-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-22 | 1998-12-22 | 1999-06-23 | $7700.00 | Window Closed / Lapsed |