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US3764937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency controlled, passively q-switch laser
Assignee: RTX Corp
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Filing: 1972-04-26
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Granted: 1973-10-09
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Expires: 1992-04-26
Abstract
Abstract A CO2 laser gain cell is optically in series with an SF6 low pressure-saturable absorber cell in a dispersive laser cavity. The optical length, and therefore the frequency of resonance of the cavity, is controlled by a piezoelectric transducer affixed to one of the cavity resonating mirrors, in response to a control voltage applied thereto, the nature of which varies in dependence upon the utility to which the device is put. In one embodiment, the PRF of the output is compared with a reference, and the resulting control voltage maintains a constant carrier frequency (such as a specific point on the P20 line at 10.6 microns), which in turn maintains a constant PRF due to the relationship between the laser gain characteristic and the saturable absorber characteristic. Rapidly changing PRF is achieved by applying a staircase voltage to the piezoelectric transducer. Carrier frequency sweeping, at different PRFs, is achieved by applying a sawtooth voltage to the piezoelectric transducer.
Inventors
- 👤 M Skolnick
- 👤 C Buczek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:11
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/11; H01S3/1123; H01S3/113; H01S3/13; H01S3/139; H01S3/1398
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
134 words
A PRF and optical carrier frequency controlled, passive Qswitched laser comprising: a dispersive laser cavity including at least a pair of mirrors, at least one of which provides output coupling of laser energy from said cavity, said cavity capable of sustaining laser oscillations over a narrow range of wavelengths; optical gain means disposed within said dispersive laser cavity and having a significant gain characteristic over a wide range of wavelengths in excess of said narrow range; a low pressure gas saturable absorber means disposed within said laser cavity, said saturable absorber means having a saturable absorption characteristic over a range of wavelengths emcompassing said narrow range but less than said wide range; and means for controlling the resonant frequency of said optical cavity thereby to control the center of said narrow range of wavelengths.
Claim 2
Dependent Claim
134 words
A PRF and optical carrier frequency controlled, passive Qswitched laser comprising: a dispersive laser cavity including at least a pair of mirrors, at least one of which provides output coupling of laser energy from said cavity, said cavity capable of sustaining laser oscillations over a narrow range of wavelengths; optical gain means disposed within said dispersive laser cavity and having a significant gain characteristic over a wide range of wavelengths in excess of said narrow range; a low pressure gas saturable absorber means disposed within said laser cavity, said saturable absorber means having a saturable absorption characteristic over a range of wavelengths emcompassing said narrow range but less than said wide range; and means for controlling the resonant frequency of said optical cavity thereby to control the center of said narrow range of wavelengths.
Claim 3
Dependent Claim
22 words
A laser according to claim 1 wherein said last named means comprises means for controlling the optical length of said optical cavity.
Claim 4
Dependent Claim
58 words
The laser according to claim 2 wherein said last named means comprises: a transducer attached to one of said mirrors and operable in response to signals applied thereto to move the mirror to which it is attached; and a control voltage source means for providing a voltage signal to said transducer to control the positioning of said mirror.
Claim 5
Dependent Claim
68 words
The laser according to claim 3 wherein said control voltage source means comprises: optical detection means responsive to pulses of laser energy coupled out of said laser cavity to produce a train of electrical signals, the frequency of which is a measure of the frequency of Q-switching of the laser; and means responsive to said train of electrical signals to generate a control voltage for controlling said transducer.
Claim 6
Dependent Claim
45 words
A laser according to claim 3 wherein said control voltage source means comprises: a reference signal source; means responsive to laser radiation coupled out of said laser and to said reference signal source for developing a control voltage to control the operation of said transducer.
Claim 7
Dependent Claim
57 words
A laser according to claim 3 wherein said control voltage source means comprises: a DC reference source; a frequency discriminator; a differential amplifier responsive to said DC reference source and to said frequency discriminator; and a driver amplifier responsive to the output of said differential amplifier, the output of said driver amplifier being connected to said transducer.
References Cited (Backward Citations)
US3622908A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |