US3688388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making q-switched diode laser
Assignee: AT&T Inc
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Filing: 1968-11-14
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Granted: 1972-09-05
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Expires: 1988-11-14
Abstract
Abstract A junction diode laser which exhibits internal Q-switching can be fabricated from a direct gap semiconductor substrate having a sufficiently low concentration of donor impurities by the steps of diffusing a shallow p-doped region into the substrate by a sufficiently slow diffusion process, heat-treating the doped substrate, applying stripe geometry electrical contacts, and forming the substrate into a laser cavity. These lasers are potentially useful in light communications systems utilizing pulse code modulation.
Inventors
- 👤 John C Dyment
- 👤 Jose E Ripper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:49
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/30; H01S5/32; H01S5/06; H01S5/0615; H10; H10H; H10H20/00; H10H20/80
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
90 words
A method for making a junction diode laser capable of exhibiting internal Q-switching comprising the steps of: forming a planar n-type substrate of gallium arsenide with free electron concentration between 0.7 X 1018 and 2.8 X 1018 per cubic centimeter; diffusing into said planar substrate by a slow diffusion process a p-doped region having a depth which is greater than the diffusion length of injected electrons and less than 4 microns; applying electrical contacts to said p-doped and n-doped regions; and forming said substrate into one or more laser cavities.
Claim 2
Independent Claim
90 words
A method for making a junction diode laser capable of exhibiting internal Q-switching comprising the steps of: forming a planar n-type substrate of gallium arsenide with free electron concentration between 0.7 X 1018 and 2.8 X 1018 per cubic centimeter; diffusing into said planar substrate by a slow diffusion process a p-doped region having a depth which is greater than the diffusion length of injected electrons and less than 4 microns; applying electrical contacts to said p-doped and n-doped regions; and forming said substrate into one or more laser cavities.
Claim 3
Dependent Claim
14 words
The method according to claim 1 wherein said electrical contacts are stripe geometry contacts.
Claim 4
Dependent Claim
71 words
The method according to claim 1 wherein: the free electron concentration of said n-type impurity is less than 1.4 X 1018 per cubic centimeter; and said p-doped region is formed in said substrate by a diffusion process using a temperature on the order of 800* C, and impurity source comprising a solution of less than 2.5 percent of acceptor material in gallium and a diffusion time of at least 4 hours.
Claim 5
Dependent Claim
23 words
The method according to claim 3 wherein said impurity source comprises a solution of less than 1 percent of acceptor material in gallium.
Claim 6
Dependent Claim
17 words
The method according to claim 3 wherein n-type impurity is tin and said p-type impurity is zinc.
Claim 7
Dependent Claim
30 words
The method according to claim 3 including the additional step of heat treating the doped substrate at a temperature between 700* C and 1,000* C for at least 30 minutes.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |