US4656641A
Expired / Lapsed
US
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Laser cavity optical system for stabilizing the beam from a phase locked multi-emitter broad emitter laser
Assignee: Xerox Corp
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Filing: 1985-02-04
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Granted: 1987-04-07
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Expires: 2005-02-04
Abstract
Abstract A laser cavity optical system is provided for stabilizing the laser far field dominate lobe so that no beam shift occurs. The laser cavity optical system comprises a lens system positioned at one facet of a phased array semiconductor laser for imaging the near field pattern of the laser comprising a single beam waist position in a first spatial direction and reimaging the far field pattern in a second spatial direction after having first focused the far field pattern in the second spatial direction to a single beam waist position. The improvement in the laser cavity optical system comprises a partially reflecting, partially transmitting mirror located at the second spatial direction beam waist position to stabilize the laser beam and prevent laser beam shift at higher operating powers and operating temperatures. Feedback means provided in the system is capable of either spatially or angularly discriminating relative to far field lobes present in a portion of said reflected light output. The mirror may also be a wavelength selective filter. Further, a slit aperture may be located at the second spatial direction beam waist position to limit the angle of aperture of the beam and thereby cutoff second, less dominate lobes present in the far field. Means to control the wavelength of the emission from the laser, such as a grating, prism, or spectral filter, may be provided in an external optical cavity at the other laser facet to provide wavelength selective reflection.
Inventors
- 👤 Donald R. Scifres
- 👤 Robert A. Sprague
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:40
CPC Classifications
G; G02; G02B; G02B19/00; G02B19/0033; G02B19/0047; G02B19/0052; G02B19/0057; G02B19/0004; G02B19/0028; G02B27/00; G02B27/09; H; H01; H01S; H01S3/00; H01S3/005; H01S5/00; H01S5/10; H01S5/14; H01S5/148; H01S5/40; H01S5/4025; H01S5/4031; H01S5/4062; H01S5/005
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
165 words
A laser cavity optical system for collimating a light output from a multi-emitter or broad emitter semiconductor laser capable of producing a multiple or broad low divergence output beam from said laser, said laser near field having a single beam waist position in a first spatial direction near the emission facet of said laser and having an elongated but phase coherent far field emitting pattern in a second spatial direction, a lens system positioned at one facet of said laser for imaging said near field of said single beam waist position in said first spatial direction and reimaging said far field pattern in said second spatial direction after having first focused said pattern in said second spatial direction to a single beam waist position, the improvement comprising a feedback means which is partially reflecting and partially transmitting and is located at the second spatial direction beam waist position to stabilize the laser beam and prevent laser beam shift at higher operating powers and operating temperatures.
Claim 2
Dependent Claim
165 words
A laser cavity optical system for collimating a light output from a multi-emitter or broad emitter semiconductor laser capable of producing a multiple or broad low divergence output beam from said laser, said laser near field having a single beam waist position in a first spatial direction near the emission facet of said laser and having an elongated but phase coherent far field emitting pattern in a second spatial direction, a lens system positioned at one facet of said laser for imaging said near field of said single beam waist position in said first spatial direction and reimaging said far field pattern in said second spatial direction after having first focused said pattern in said second spatial direction to a single beam waist position, the improvement comprising a feedback means which is partially reflecting and partially transmitting and is located at the second spatial direction beam waist position to stabilize the laser beam and prevent laser beam shift at higher operating powers and operating temperatures.
Claim 3
Dependent Claim
28 words
The laser cavity optical system of claim 1 wherein said portion of said reflected light output is spatially discriminated by said feedback means to stabilize said output beam.
Claim 4
Dependent Claim
28 words
The laser cavity optical system of claim 1 wherein said portion of said reflected light output is angularly discriminated by said feedback means to stabilize said output beam.
Claim 5
Dependent Claim
16 words
The laser cavity optical system of claim 1 wherein said feedback means comprises a planar mirror.
Claim 6
Dependent Claim
22 words
The laser cavity optical system of claim 4 wherein said planar mirror is rotatable in the plane of said second spatial direction.
Claim 7
Dependent Claim
31 words
The laser cavity optical system of claim 4 wherein a slot aperture is located at said second spatial direction beam waist position between said planar mirror and said laser optial cavity.
Claim 8
Dependent Claim
22 words
The laser cavity optical system of claim 4 wherein said planar mirror is mounted in an aperture of a light absorbing plate.
Claim 9
Dependent Claim
34 words
The laser cavity optical system of claim 1 wherein said feedback means comprises a curved mirror with the inside surface thereof positioned to reflect said light output portion back into said laser optical cavity.
Claim 10
Dependent Claim
31 words
The laser cavity optical system of claim 8 wherein a slot aperture is located at said second spatial direction beam waist position between said curved mirror and said laser optical cavity.
Claim 11
Dependent Claim
22 words
The laser cavity optical system of claim 8 wherein the radius of curvature of said mirror is in said second spatial direction.
Claim 12
Dependent Claim
31 words
The laser cavity optical system of claim 10 wherein a slot aperture is located at said second spatial direction beam waist position between said curved mirror and said laser optical cavity.
Claim 13
Dependent Claim
34 words
The laser cavity optical system of claim 1 wherein said feedback means comprises a spherical mirror with the inside surface thereof positioned to reflect said light output portion back into said laser optical cavity.
Claim 14
Dependent Claim
36 words
The laser cavity optical system of claim 12 wherein a straight edge aperture is located between said laser facet and said spherical mirror to limit the angle of acceptance of said beam at said spherical mirror.
Claim 15
Dependent Claim
34 words
The laser cavity optical system of claim 1 wherein said feedback means comprises a curved mirror with the outside surface thereof positioned to reflect said light output portion back into said laser optical cavity.
Claim 16
Dependent Claim
28 words
The laser cavity optical system of claim 1 wherein said feedback means comprises a partially reflecting, partially transmitting mirror located at said second spatial direction beam waist position.
Claim 17
Dependent Claim
37 words
The laser cavity optical system of claim 15 wherein a slit aperture is located at said second spatial direction beam waist position to limit the angle of acceptance of said beam, said mirror mounted in said aperture.
Claim 18
Dependent Claim
20 words
The laser cavity optical system of claim 15 wherein said mirror is a partially reflecting, partially transmitting wavelength selective filter.
Claim 19
Dependent Claim
35 words
The laser cavity optical system of claim 15 wherein there is means positioned at the other facet of said laser to selectively reflect from the laser emission a desired wavelength as feedback to said laser.
Claim 20
Dependent Claim
31 words
The laser cavity optical system of claim 18 wherein in said selective means comprises a grating, a prism plus plane mirror, a plane mirror, a concave mirror, a wavelength selective mirror.
Claim 21
Dependent Claim
19 words
The laser cavity optical system of claim 19 wherein in said wavelength is selected by rotation of said grating.
Claim 22
Dependent Claim
17 words
The laser cavity optical system of claim 20 wherein said selective means comprises a wavelength selective mirror.
Claim 23
Dependent Claim
18 words
The laser cavity optical system of claim 21 wherein said wavelength selective mirror is a multilayer dielectric stack.
Claim 24
Dependent Claim
23 words
The laser cavity optical system of claim 18 wherein said selective wavelength reflection means comprises a spectral filter aligned to receive said emission.
Claim 25
Dependent Claim
47 words
The laser cavity optical system of claim 18 wherein said selective wavelength reflection means comprises a GRIN rod lens aligned to receive said light output with a multilayer dielectric reflecting stack mounted on the end of said rod opposite to the end aligned to receive said output.
Claim 26
Dependent Claim
20 words
The laser cavity optical system of claim 24 wherein an AR coating is provided on said rod output receiving end.
Claim 27
Dependent Claim
18 words
The laser cavity optical of claim 24 wherein PAR coating is provided on said rod output receiving end.
Claim 28
Dependent Claim
21 words
The laser cavity optical system of claim 1 which includes spatially positioned aperture means between said feedback means and said laser.
Claim 29
Dependent Claim
27 words
The laser cavity optical system of claim 1 wherein said feedback means is angularly adjustable relative to the path of said output to provide spatial mode control.
Claim 30
Dependent Claim
24 words
The laser cavity optical system of claim 1 wherein said feedback means is laterally adjustable relative to said output to provide spatial mode control.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-04-06 | 1990-10-06 | 1991-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-06 | 1994-10-06 | 1995-04-07 | $3760.00 | Window Closed / Lapsed |
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