US4956844A
Expired / Lapsed
US
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Two-dimensional surface-emitting laser array
Assignee: Massachusetts Institute of Technology
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Filing: 1989-03-17
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Granted: 1990-09-11
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Expires: 2009-03-17
Abstract
Abstract An improved two-dimensional semiconductor surface-emitting laser array is described in which two intra-cavity internal reflecting surfaces are formed at a 45° angle to the plane of the active layer of the semiconductor laser so as to internally reflect light from each end of the active layer in a direction normal to the plane of the active layer with a buried reflective mirror provided in the path of one of said reflections, so as to transmit reflected light back through the laser and out the top surface of the array.
Inventors
- 👤 William D. Goodhue
- 👤 Kurt Rauschenbach
- 👤 Christine A. Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:35
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/40; H01S5/42; H01S5/10; H01S5/18; H01S5/185
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
140 words
A two-dimensional semiconductor surface-emitting laser array formed of a plurality of laser cavities each comprising: (a) an active layer of lasing semiconductor material for emitting rays of light extending longitudinally in a plane between two semiconductor layers; (b) a first intra-cavity reflective surface formed at one end of said layer and bisecting the plane of said active layer at an angle which internally reflects said light rays from said layer in a first direction approximately normal to said plane; (c) a second intra-cavity reflective surface formed at an opposite end of said layer and bisecting said plane at about the same angle as in (b) to internally reflect light rays from said layer in a second direction opposite said first direction and approximately normal to said plane; (d) a light reflective mirror formed in the path of said second direction.
Claim 2
Dependent Claim
140 words
A two-dimensional semiconductor surface-emitting laser array formed of a plurality of laser cavities each comprising: (a) an active layer of lasing semiconductor material for emitting rays of light extending longitudinally in a plane between two semiconductor layers; (b) a first intra-cavity reflective surface formed at one end of said layer and bisecting the plane of said active layer at an angle which internally reflects said light rays from said layer in a first direction approximately normal to said plane; (c) a second intra-cavity reflective surface formed at an opposite end of said layer and bisecting said plane at about the same angle as in (b) to internally reflect light rays from said layer in a second direction opposite said first direction and approximately normal to said plane; (d) a light reflective mirror formed in the path of said second direction.
Claim 3
Dependent Claim
43 words
The array of claim 1 wherein the reflective mirror is comprised of layers of semiconductor dielectric material formed in parallel to said active layer in the path of one of said light rays to redirect said light rays back through said active layer.
Claim 4
Dependent Claim
87 words
The array of claim 1 wherein the array is comprised of layers of semiconductor material forming waveguiding regions above and below said active layer and the first and second reflective surfaces are formed by etching semiconductor material to bisect said active layer at an angle of about 45° from the plane of said active layer leaving an air gap at each end having two sidewalls, each of which is inclined in the same direction at said angle of about 45° from the plane of said active layer.
Claim 5
Dependent Claim
18 words
The array of claim 1 further including an output mirror formed in the path of said first direction.
Claim 6
Dependent Claim
18 words
The array of claim 4 wherein the output mirror is formed on an external surface of said array.
Claim 7
Dependent Claim
15 words
The array of claim 1 wherein the lasing semiconductor material is formed of III-IV material.
Claim 8
Dependent Claim
128 words
In a method for forming two-dimensional semiconductor surface-emitting laser arrays the improvement comprising: (a) forming a first light reflective mirror structure on a substrate; (b) forming a light-emitting device over said first mirror structure with a layer of light-emitting semiconductor material extending along a plane parallel to said substrate for emitting light extending in said plane; (c) removing semiconductor material from said device at opposite ends thereof at an angle of about 45° to said plane forming intra-cavity light reflecting surfaces at each end of said device which surfaces deflect said light in opposite directions normal to said plane; (d) forming an output mirror on said light-emitting device over one of said light reflective intra-cavity surfaces; (e) forming contacts on the surface of said device and said substrate.
Claim 9
Dependent Claim
128 words
In a method for forming two-dimensional semiconductor surface-emitting laser arrays the improvement comprising: (a) forming a first light reflective mirror structure on a substrate; (b) forming a light-emitting device over said first mirror structure with a layer of light-emitting semiconductor material extending along a plane parallel to said substrate for emitting light extending in said plane; (c) removing semiconductor material from said device at opposite ends thereof at an angle of about 45° to said plane forming intra-cavity light reflecting surfaces at each end of said device which surfaces deflect said light in opposite directions normal to said plane; (d) forming an output mirror on said light-emitting device over one of said light reflective intra-cavity surfaces; (e) forming contacts on the surface of said device and said substrate.
Claim 10
Dependent Claim
14 words
The method of claim 7 wherein the light-emitting device is a III-V heterostructure laser.
Claim 11
Dependent Claim
16 words
The method of claim 8 wherein the III-V heterostructure is formed of AlGaAs and GaAs layers.
Claim 12
Dependent Claim
18 words
The method of claim 7 wherein the first mirror structure is formed of alternate quarter wavelength III-V layers.
Claim 13
Dependent Claim
33 words
The method of claim 7 wherein the light-emitting device includes a first doped contacting layer and includes the step of removing said contacting layer in the region where said output mirror is formed.
Claim 14
Dependent Claim
10 words
The method of claim 11 wherein the mirror is passivated.
Claim 15
Dependent Claim
14 words
The method of claim 12 wherein the mirror is coated with an anti-reflective coating.
Claim 16
Dependent Claim
19 words
The method of claim 12 wherein the mirror is coated with material to adjust the reflectivity of the mirror.
Claim 17
Dependent Claim
15 words
The method of claim 7 wherein the semiconductor material is removed by ion-beam assisted etching.
Claim 18
Dependent Claim
27 words
The method of claim 7 wherein the output mirror is coated with Al 3 O 2 , SiO 2 , ZrO 2 , or a combination thereof.
Claim 19
Dependent Claim
57 words
The method of claim 7 wherein the reflective surfaces are formed by etching semiconductor material to bisect said plane at an angle of about 45°, leaving an air gap at each end having two sidewalls, each of which is inclined in the same direction at said angle of about 45° from the plane of said active layer.
Claim 20
Dependent Claim
137 words
In a semiconductor surface-emitting laser array having an active layer of lasing semiconductor material for emitting rays of light extending longitudinally in a plane between two semiconductor layers, the improvement comprising: (a) a first intra-cavity reflective surface formed at one end of said active layer and bisecting the plane of said active layer at an angle which internally reflects said light rays from said layer in a first direction approximately normal to said plane; and (b) a second intra-cavity reflective surface formed at an opposite end of said layer and bisecting said plane at about the same angle as in (a) to internally reflect light rays from said layer in a second direction opposite said first direction and approximately normal to said plane; and (c) a light reflective mirror formed in the path of said second direction.
Claim 21
Dependent Claim
137 words
In a semiconductor surface-emitting laser array having an active layer of lasing semiconductor material for emitting rays of light extending longitudinally in a plane between two semiconductor layers, the improvement comprising: (a) a first intra-cavity reflective surface formed at one end of said active layer and bisecting the plane of said active layer at an angle which internally reflects said light rays from said layer in a first direction approximately normal to said plane; and (b) a second intra-cavity reflective surface formed at an opposite end of said layer and bisecting said plane at about the same angle as in (a) to internally reflect light rays from said layer in a second direction opposite said first direction and approximately normal to said plane; and (c) a light reflective mirror formed in the path of said second direction.
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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) | 1993-09-10 | 1994-03-12 | 1994-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-10 | 1998-03-12 | 1998-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-10 | 2002-03-12 | 2002-09-11 | $7700.00 | Window Closed / Lapsed |