US3748595A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helium-cadmium laser and method for optimum operation
Assignee: Applied Biosystems Inc
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Filing: 1970-03-06
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Granted: 1973-07-24
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Expires: 1990-03-06
Abstract
Abstract Means for introducing cadmium vapor into a helium laser tube and for maintaining optimum vapor pressure are disclosed in the form of a steel jacketed hollow cadmium cylinder mounted coaxially within the laser tube between the anode and cathode, and surrounded by an evacuated bulb. Plasma discharge of the ionized helium gas passes through and heats the hollow cadmium cylinder to produce cadmium vapor, thus eliminating any need for an auxiliary heater. A method of selecting and adjusting the plasma discharge current to optimum value is also disclosed.
Inventors
- 👤 J Rigden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:12
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/02; H01S3/03; H01S3/031
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
57 words
The combination of claim 1 wherein electrical power is applied to said laser tube from a constant current source whereby heating of the metallic cadmium produces cadmium vapor which combining with the helium gas reduces the electrical impedance thereof, thereby reducing the heat dissipated by the constant current discharge to effectively self-regulate the production of cadmium vapor.
Claim 2
Dependent Claim
17 words
a coaxial anode sealingly mounted within an enlarged portion of said laser tube adjacent one end thereof,
Claim 3
Dependent Claim
18 words
a coaxial cathode sealingly mounted within an enlarged portion of said laser tube adjacent the opposite end thereof,
Claim 4
Dependent Claim
103 words
In a helium-cadmium optical laser tube, means for introducing a partial pressure of cadmium vapor into a helium buffer within the laser tube comprising, a hollow cadmium cylinder having an axial bore therethrough, and means supporting said hollow cadmium cylinder with its axial bore coaxial within said laser tube, whereby plasma of said helium buffer passes through the axial bore of said hollow cadmium cylinder thereby heating and vaporizing cadmium from said cylinder into said helium buffer, and a forced fitting stainless steel cover tube encircling said hollow cadmium cylinder to prevent vaporization except from the internal axial bore of said cadmium cylinder.
Claim 5
Dependent Claim
82 words
In a helium-cadmium laser the method of selecting a critical value of constant discharge current for optimum laser operation which comprises the steps of A. applying modulation to the laser tube current to produce a modulation on the laser light, B. comparing the phase relation between the modulations of tube current and the modulation of laser light, C. increasing the tube current if the modulations are 180* out of phase, and D. decreasing the tube current if the modulations are in phase.
Claim 6
Dependent Claim
83 words
an enlarged cylindrical chamber sealingly mounted to and surrounding said laser tube at a position between said anode and cathode, in closer proximity to said anode, a. a hollow metallic cylindEr of cadmium inserted in said laser tube and within said enlarged cylindrical chamber, coaxial with the longitudinal central axis of said laser tube, b. a close fitting stainless steel cylindrical tube surrounding the outer surface of said hollow cadmium cylinder, c. insulating means surrounding the outer surface of said enlarged cylindrical chamber,
Claim 7
Dependent Claim
48 words
helium gas under pressure within said lase tube and, B. a pair of concave spherical mirrors positioned at opposite ends of said laser tube in proximity to said planar windows and having the centers of their spherical surfaces normal to the longitudinal central axis of said laser tube.
Claim 8
Dependent Claim
18 words
A helium-cadmium laser comprising in combination, A. an elongated laser tube having a straight line central longitudinal axis,
References Cited (Backward Citations)
US3464025A
Cited
US3621460A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |