Patent US4489415A successfully refreshed from Google Patents.
US4489415A
Expired / Lapsed
US
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Pulse pumping an optically pumped laser
Assignee: General Electric Co
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Filing: 1982-07-12
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Granted: 1984-12-18
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Expires: 2002-07-12
Abstract
Abstract An efficient power supply employs a high current switching transistor to pulse a flashlamp for optical pumping in lasers, such as an Nd:YAG laser at high pulse repetition frequencies. The pulsing circuit offers a simple, flexible, and precise means of pump pulse control. Flashlamp simmer current is provided from the constant dc voltage source with a resistor in parallel with the switching transistor.
Inventors
- 👤 William B. Jones, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:41
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/09; H01S3/091; H01S3/0915; H01S3/092; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/34
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
109 words
In an optically pumped laser having a gaseous discharge flashlamp for pumping the laser and a pulsing circuit that generates flashlamp current pulses, the improvement wherein said pulsing circuit comprises: a high current switching transistor in series with said flashlamp and connected to a source of dc voltage; a control circuit for generating base drive pulses which render said switching transistor conductive to pulse said flashlamp; wherein said switching transistor is a Darlington pair and said control circuit injects currents into the base of both transistors; and means in parallel with said switching transistor to provide a path for flashlamp simmer current during nonconducting intervals of said switching transistor.
Claim 2
Dependent Claim
109 words
In an optically pumped laser having a gaseous discharge flashlamp for pumping the laser and a pulsing circuit that generates flashlamp current pulses, the improvement wherein said pulsing circuit comprises: a high current switching transistor in series with said flashlamp and connected to a source of dc voltage; a control circuit for generating base drive pulses which render said switching transistor conductive to pulse said flashlamp; wherein said switching transistor is a Darlington pair and said control circuit injects currents into the base of both transistors; and means in parallel with said switching transistor to provide a path for flashlamp simmer current during nonconducting intervals of said switching transistor.
Claim 3
Dependent Claim
17 words
The laser of claim 1 wherein said control circuit generates adjustable pulse length and repetition frequency pulses.
Claim 4
Dependent Claim
22 words
The laser of claim 1 wherein said flashlamp is filled with a mixture of krypton and xenon at about 2 atmospheres pressure.
Claim 5
Dependent Claim
32 words
In an optically pumped, Q-switched Nd:YAG laser having a gaseous discharge flashlamp for pumping the laser and a pulsing circuit that generates flashlamp current pulses, the improvement wherein said pulsing circuit comprises:
Claim 6
Dependent Claim
32 words
In an optically pumped, Q-switched Nd:YAG laser having a gaseous discharge flashlamp for pumping the laser and a pulsing circuit that generates flashlamp current pulses, the improvement wherein said pulsing circuit comprises:
Claim 7
Dependent Claim
68 words
a high current Darlington switching transistor in series with said flashlamp and connected to a source of constant dc voltage; a control circuit for generating adjustable pulse length and repetition frequency base drive pulses which render said switching transistor conductive to pulse said flashlamp; and a resistor in parallel with said switching transistor to provide a path for flashlamp simmer current during nonconducting intervals of said switching transistor.
Claim 8
Dependent Claim
68 words
a high current Darlington switching transistor in series with said flashlamp and connected to a source of constant dc voltage; a control circuit for generating adjustable pulse length and repetition frequency base drive pulses which render said switching transistor conductive to pulse said flashlamp; and a resistor in parallel with said switching transistor to provide a path for flashlamp simmer current during nonconducting intervals of said switching transistor.
Claim 9
Dependent Claim
34 words
The laser of claim 4 wherein said control circuit comprises means for generating signal level pulses, a current amplifier, and a voltage divider connected to the bases of both transistors of the Darlington device.
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) | 1987-12-18 | 1988-06-18 | 1988-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-18 | 1992-06-18 | 1992-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-18 | 1996-06-18 | 1996-12-18 | $7700.00 | Window Closed / Lapsed |