US4615034A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultra-narrow bandwidth optical thin film interference coatings for single wavelength lasers
Assignee: Spectra Physics Lasers Inc A De Corp
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Filing: 1984-03-30
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Granted: 1986-09-30
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Expires: 2004-03-30
Abstract
Abstract A wavelength selective mirror provides single wavelength operation of a gas laser. In a specific embodiment an output coupler optical interference coating allows oscillation of the 488.0 nanometer line of the Argon ion laser blue/green spectrum while suppressing all other lines in that spectrum, particularly adjacent lines at 476.5 nanometers and 496.5 nanometers.
Inventors
- 👤 Marc K. von Gunten
- 👤 Benjamin H. Cook
- 👤 David C. Gerstenberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:53
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/08059
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
161 words
A laser of the kind which can oscillate on more than one wavelength simultaneously, said laser comprising, a single resonant optical cavity, an optical gain medium, at least two reflective mirrors delimiting the optical cavity, and coating means on at least one mirror surface for providing operation of said laser at any selected single or band of wavelengths, including any weak or low gain wavelengths, independent of their optical gains and at substantially any current or power level while suppressing non-selected wavelengths such that, said coating adjusts thresholds of all selected and non-selected wavelengths, including any dominant or high gain wavelengths, said coating having a coating reflectance to support laser oscillation for said selected single or band of wavelengths such that said selected single wavelength or band of wavelengths are above threshold, said coating further having a coating reflectance to suppress laser oscillation at said non-selected wavelengths, including dominant or high gain wavelengths, such that said non-selected wavelengths are below threshold.
Claim 2
Dependent Claim
161 words
A laser of the kind which can oscillate on more than one wavelength simultaneously, said laser comprising, a single resonant optical cavity, an optical gain medium, at least two reflective mirrors delimiting the optical cavity, and coating means on at least one mirror surface for providing operation of said laser at any selected single or band of wavelengths, including any weak or low gain wavelengths, independent of their optical gains and at substantially any current or power level while suppressing non-selected wavelengths such that, said coating adjusts thresholds of all selected and non-selected wavelengths, including any dominant or high gain wavelengths, said coating having a coating reflectance to support laser oscillation for said selected single or band of wavelengths such that said selected single wavelength or band of wavelengths are above threshold, said coating further having a coating reflectance to suppress laser oscillation at said non-selected wavelengths, including dominant or high gain wavelengths, such that said non-selected wavelengths are below threshold.
Claim 3
Dependent Claim
31 words
The invention defined in claim 1 wherein the coating means provide single wavelength operation of the laser by allowing oscillation of one line while suppressing oscillation of closely spaced adjacent lines.
Claim 4
Dependent Claim
68 words
The invention defined in claim 2 wherein the coating means have spectral characteristics sufficiently narrow to allow oscillation of said one line by providing the appropriate optical reflectance for oscillation of said one line and to suppress oscillation of said closely spaced adjacent lines by providing the necessary optical transmittance through the mirror in order to suppress oscillation at the wavelengths corresponding to said closely spaced adjacent lines.
Claim 5
Dependent Claim
36 words
The invention defined in claim 1 wherein the laser is an internal mirror gas laser and at least one mirror has an internal surface exposed to a plasma environment within the cavity of the gas laser.
Claim 6
Dependent Claim
21 words
The invention defined in claim 1 wherein at least one laser mirror is external to a plasma environment within the laser.
Claim 7
Dependent Claim
47 words
The invention defined in claim 1 wherein the laser is an Argon ion gas laser and the coating means provide appropriate reflectance for oscillation of one of the following: a. 457.9 nanometers; b. 476.5 nanometers; c. 488.0 nanometers; d. 514.5 nanometers; e. 351.1 nanometers; f. 363.8 nanometers.
Claim 8
Dependent Claim
15 words
The invention defined in claim 1 where the laser is a Krypton ion gas laser.
Claim 9
Dependent Claim
31 words
The invention defined in claim 1 wherein the coating means comprise multilayer stacks of dielectric materials of alternating high and low refractive index values which reflect over a fairly narrow bandwidth.
Claim 10
Dependent Claim
32 words
The invention defined in claim 8 wherein the wavelength bandwidth of the coating stack is a function of the order of the reflectance zone and the optical thickness of each individual layer.
Claim 11
Dependent Claim
49 words
The invention defined in claim 9 wherein the laser is an Argon ion gas laser, the coating means are constructed to provide single wavelength operation at 488.0 nanometers, and the coating means comprise alternating layers of aluminum oxide (Al 2 O 3 ) and silicon dioxide (SiO 2 ).
Claim 12
Dependent Claim
30 words
The invention defined in claim 1 wherein the coating means comprise dielectric materials having differences in optical indices of refraction effective to determine the narrow width of the reflectance band.
Claim 13
Dependent Claim
45 words
The invention defined in claim 11 wherein said dielectric materials can survive the sustained high temperatures required for hard sealing the mirror to the associated cavity structure without fracture, re-evaporation from the substrate or other degradation to the optical or physical characteristics of the coating.
Claim 14
Dependent Claim
40 words
The invention defined in claim 12 wherein said dielectric materials can survive the vacuum environment and ultraviolet radiation coming from the arc discharge in plasma tubes of gas lasers without degradation to the optical or physical characteristics of the coating.
Claim 15
Dependent Claim
26 words
The invention defined in claim 13 wherein the coating means comprise layers of aluminum oxide (Al 2 O 3 ) and silicon dioxide (SiO 2 ).
Claim 16
Independent Claim
218 words
A method of producing single wavelength operation of a laser of the kind which can oscillate on a number of lines simultaneously, at substantially any input power level, said method comprising, coating a mirror surface with a coating having optical characteristics which provide for operation of said laser at any selected single or band of wavelengths, including any weak or low gain wavelengths, independent of their optical gains and at substantially any current or power level while suppressing non-selected wavelengths such that, said coating adjusts thresholds of all selected and non-selected wavelengths, including any dominant or high gain wavelengths, said coating having a coating reflectance to support laser oscillation for said selected single or band of wavelengths such that said selected single wavelength or band of wavelengths are above threshold, said coating further having a coating reflectance to suppress laser oscillation at said non-selected wavelengths, including dominant or high gain wavelengths, such that said non-selected wavelengths are below threshold, mounting the mirror with respect to an optical cavity of the laser in a position where the mirror coating is effective to allow oscillation for said selected single or band of wavelengths, and operating the laser at a high input power level, above a threshold at which the laser would otherwise begin to oscillate a number of lines simultaneously.
Claim 17
Independent Claim
218 words
A method of producing single wavelength operation of a laser of the kind which can oscillate on a number of lines simultaneously, at substantially any input power level, said method comprising, coating a mirror surface with a coating having optical characteristics which provide for operation of said laser at any selected single or band of wavelengths, including any weak or low gain wavelengths, independent of their optical gains and at substantially any current or power level while suppressing non-selected wavelengths such that, said coating adjusts thresholds of all selected and non-selected wavelengths, including any dominant or high gain wavelengths, said coating having a coating reflectance to support laser oscillation for said selected single or band of wavelengths such that said selected single wavelength or band of wavelengths are above threshold, said coating further having a coating reflectance to suppress laser oscillation at said non-selected wavelengths, including dominant or high gain wavelengths, such that said non-selected wavelengths are below threshold, mounting the mirror with respect to an optical cavity of the laser in a position where the mirror coating is effective to allow oscillation for said selected single or band of wavelengths, and operating the laser at a high input power level, above a threshold at which the laser would otherwise begin to oscillate a number of lines simultaneously.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-29 | 1990-03-31 | 1990-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-29 | 1994-03-31 | 1994-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-29 | 1998-03-31 | 1998-09-30 | $7700.00 | Window Closed / Lapsed |