US4843611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Superluminescent diode and single mode laser
Assignee: Agere Systems LLC
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Filing: 1988-08-12
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Granted: 1989-06-27
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Expires: 2008-08-12
Abstract
Abstract A buried heterostructure window device has an elongated layer of gain medium surrounded by a lower index of refraction medium for guiding light along the length of the gain medium. A window and an antireflective layer are deposited on the output end of the gain layer to minimize reflections. A portion of the gain medium nearer the output end of the device is electrically pumped, leaving an unpumped end of the gain medium remote from the output end. The unpumped portion of the gain medium absorbs light travelling along the length of the gain medium. This inhibits reflection from the end of the gain medium remote from the output end. When the device is pumped with a moderate power level, strong superluminescent output is obtained. When the device is pumped well above the lasing threshold by reason of "burning through" the unpumped absorbing portion of the gain medium, a single mode laser is obtained with side band power at least 20 db below the power of the principal oscillation mode. "Burning through" the unpumped absorbing portion can be inhibited by extracting current carriers from that portion of the medium.
Inventors
- 👤 Sze-Keung Kwong
- 👤 Kam Y. Lau
- 👤 Nadav Bar-Chaim
- 👤 Israel Ury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:59
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/042; H01; H01S; H01S5/00; H01S5/06; H01S5/0601; H01S5/10; H01S5/16; H01S5/164; H01S5/04; H01S5/042; H01S5/0425; H01S5/04256; H01S5/0602
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
102 words
A buried heterostructure superluminescent diode comprising: an elongated active gain layer having an output end and a non-output end; a first n-type cladding layer on one face of the gain layer and a second p-type cladding layer on the other face of the gain layer for pumping the active gain layer, the cladding layer having a lower index of refraction than the active gain layer; a blocking layer having a lower index of refraction than the active gain layer along each longitudinal edge of the active gain layer; and a light absorbing medium at the non-output end of the active gain layer.
Claim 2
Dependent Claim
102 words
A buried heterostructure superluminescent diode comprising: an elongated active gain layer having an output end and a non-output end; a first n-type cladding layer on one face of the gain layer and a second p-type cladding layer on the other face of the gain layer for pumping the active gain layer, the cladding layer having a lower index of refraction than the active gain layer; a blocking layer having a lower index of refraction than the active gain layer along each longitudinal edge of the active gain layer; and a light absorbing medium at the non-output end of the active gain layer.
Claim 3
Dependent Claim
30 words
A superluminescent diode as recited in claim 1 further comprising a second transparent window at the opposite end of the absorbing medium from the end of the active gain layer.
Claim 4
Dependent Claim
27 words
A superluminescent diode as recited in claim 1 further comprising a reflective mirror at the opposite end of the light absorbing medium from the active gain layer.
Claim 5
Dependent Claim
15 words
A superluminescent diode as recited in claim 1 wherein the active gain layer comprises InGaAsP.
Claim 6
Dependent Claim
22 words
A superluminescent diode as recited in claim 1 wherein the absorbing medium comprises unpumped material the same as the active gain layer.
Claim 7
Dependent Claim
19 words
A superluminescent diode as recited in claim 1 further comprising means for extracting current carriers from the absorbing medium.
Claim 8
Dependent Claim
81 words
A buried heterostructure superluminescent diode comprising: an elongated layer of gain medium having an output end and a non-output end; means for pumping only a portion of the gain medium nearer the output end for stimulating emission of radiation in the pumped portion and leaving the balance of the gain medium as a light absorbing medium; and a medium along each side edge of the gain medium having a lower index of refraction than the gain medium for guiding light therein.
Claim 9
Dependent Claim
81 words
A buried heterostructure superluminescent diode comprising: an elongated layer of gain medium having an output end and a non-output end; means for pumping only a portion of the gain medium nearer the output end for stimulating emission of radiation in the pumped portion and leaving the balance of the gain medium as a light absorbing medium; and a medium along each side edge of the gain medium having a lower index of refraction than the gain medium for guiding light therein.
Claim 10
Dependent Claim
14 words
A superluminescent diode as recited in claim 7 wherein the gain medium comprises InGaAsP.
Claim 11
Dependent Claim
37 words
A superluminescent diode as recited in claim 7 further including a second unpumped portion of the gain medium between the pumped portion and the window, the second unpumped portion being shorter than the first mentioned unpumped portion.
Claim 12
Dependent Claim
51 words
A superluminescent diode as recited in claim 7 further comprising a reflective mirror at the end of the unpumped portion of the gain medium remote from the pumped portion of the gain medium for operation of the superluminescent diode as a single mode laser when the light absorbing medium becomes transparent.
Claim 13
Dependent Claim
23 words
A superluminescent diode as recited in claim 7 further comprising means for extracting current carriers from the unpumped portion of the gain medium.
Claim 14
Dependent Claim
109 words
A single mode semiconductor buried heterostructure laser comprising: an elongated active gain layer having an output end and a non-output end; a first n-type cladding layer on one face of the gain layer and a second p-type cladding layer on the other face of the gain layer for pumping the active gain layer, the cladding layer having a lower index of refraction than the active gain layer; a blocking layer having a lower index of refraction than the active gain layer along each longitudinal edge of the active gain layer; and a light absorbing medium at the non-output end of the active gain layer for suppressing side mode oscillation.
Claim 15
Dependent Claim
109 words
A single mode semiconductor buried heterostructure laser comprising: an elongated active gain layer having an output end and a non-output end; a first n-type cladding layer on one face of the gain layer and a second p-type cladding layer on the other face of the gain layer for pumping the active gain layer, the cladding layer having a lower index of refraction than the active gain layer; a blocking layer having a lower index of refraction than the active gain layer along each longitudinal edge of the active gain layer; and a light absorbing medium at the non-output end of the active gain layer for suppressing side mode oscillation.
Claim 16
Dependent Claim
27 words
A superluminescent diode as recited in claim 12 further comprising a reflective mirror at the opposite end of the light absorbing medium from the active gain layer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |