US4815090A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distributed feedback semiconductor laser with monitor
Assignee: KDDI Corp
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Filing: 1988-03-07
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Granted: 1989-03-21
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Expires: 2008-03-07
Abstract
Abstract A distributed feedback semiconductor laser with monitor is disclosed, in which the energy gap of a light absorbing layer provided on the window region alone is smaller than the energy gap of the light emitting layer, and in which an independent pn junction isolated from the pn junction in the laser region is provided in or at one edge of the light absorbing layer on the window region.
Inventors
- 👤 Masashi Usami
- 👤 Shigeyuki Akiba
- 👤 Katsuyuki Utaka
- 👤 Yuichi Matsushima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:42
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/02; H01S5/026; H01S5/0262; H01S5/0264; H01S5/10; H01S5/12; H01S5/16; H01S5/164
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
154 words
A distributed feedback semiconductor laser with monitor, comprising: a laser region having a light emitting layer, an effective periodic refractive index variation along the direction of travel of light and a pn junction provided in the vicinity of the light emitting layer; a window region formed by burying in at least one end of the light emitting layer a semiconductor layer of a larger energy gap than that of the light emitting layer; and a light absorbing layer formed on the window region; wherein the energy gap of the light absorbing layer is set to a value smaller than the energy gap of the light emitting layer, and a pn junction isolated from the pn junction in the laser region is provided in the light absorbing layer on the window region so that a part of a light output from the light emitting layer is monitored through the pn junction in the window region.
Claim 2
Dependent Claim
154 words
A distributed feedback semiconductor laser with monitor, comprising: a laser region having a light emitting layer, an effective periodic refractive index variation along the direction of travel of light and a pn junction provided in the vicinity of the light emitting layer; a window region formed by burying in at least one end of the light emitting layer a semiconductor layer of a larger energy gap than that of the light emitting layer; and a light absorbing layer formed on the window region; wherein the energy gap of the light absorbing layer is set to a value smaller than the energy gap of the light emitting layer, and a pn junction isolated from the pn junction in the laser region is provided in the light absorbing layer on the window region so that a part of a light output from the light emitting layer is monitored through the pn junction in the window region.
Claim 3
Dependent Claim
40 words
A distributed feedback semiconductor laser with monitor according to claim 1, further comprising an antireflection coating film provided at one end of the laser region to pass therethrough the main part of the light output from the light emitting layer.
Claim 4
Dependent Claim
37 words
A distributed feedback semiconductor laser with monitor according to claim 1, in which the light absorbing layer is formed on a p-type layer having a value of energy gap larger than that of the light emitting layer.
Claim 5
Dependent Claim
157 words
A distributed feedback semiconductor laser with monitor, comprising: a laser region having a light emitting layer, an effective periodic refractive index variation along the direction of travel of light and a pn junction provided in the vicinity of the light emitting layer; a window region formed by burying in at least one end of the light emitting layer a semiconductor layer of a larger energy gap than that of the light emitting layer; and a light absorbing layer formed on the window region; wherein the energy gap of the light absorbing layer is set to a value smaller than the energy gap of the light emitting layer, and a pn junction isolated from the pn junction in the laser region is provided at one edge of the light absorbing layer on the window region so that a part of a light output from the light emitting layer is monitored through the pn junction in the window region.
Claim 6
Dependent Claim
157 words
A distributed feedback semiconductor laser with monitor, comprising: a laser region having a light emitting layer, an effective periodic refractive index variation along the direction of travel of light and a pn junction provided in the vicinity of the light emitting layer; a window region formed by burying in at least one end of the light emitting layer a semiconductor layer of a larger energy gap than that of the light emitting layer; and a light absorbing layer formed on the window region; wherein the energy gap of the light absorbing layer is set to a value smaller than the energy gap of the light emitting layer, and a pn junction isolated from the pn junction in the laser region is provided at one edge of the light absorbing layer on the window region so that a part of a light output from the light emitting layer is monitored through the pn junction in the window region.
Claim 7
Dependent Claim
40 words
A distributed feedback semiconductor laser with monitor according to claim 4, further comprising an antireflection coating film provided at one end of the laser region to pass therethrough the main part of the light output from the light emitting layer.
Claim 8
Dependent Claim
37 words
A distributed feedback semiconductor laser with monitor according to claim 4, in which the light absorbing layer is formed on a p-type layer having a value of energy gap larger than that of the light emitting layer.
References Cited (Backward Citations)
US4653058A
Cited
US4720835A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |