EP1130712A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical amplifier monitor using a blazed grating
Assignee: Lumentum Ottawa Inc
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Filing: 2001-01-30
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Granted: —
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Expires: 2021-01-30
Abstract
Abstract The traditional solution to monitoring the pump laser power uses the back facet of the pump laser to monitor its power. However, stability and aging issues of the back facet may make it difficult or even impossible to measure the pump power to a high degree of accuracy using this method. Pump lasers often use fiber Bragg gratings to stabilize their wavelength. However, if an in-line optical fiber blazed Bragg grating is used, then the pump power is coupled out of the grating to a detector and monitored. The method of the present invention minimizes components and provides a direct monitoring of fiber coupled power. Alternatively, light coupled out of a WDM is used in a similar manner to monitor the pump power.
Inventors
- 👤 Jennifer Aspell
- 👤 Donald R. Zimmerman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 21:16
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/14; H01S5/146; H01S5/06; H01S5/068; H01S5/0683; H01S5/0687; H01S3/00; H01S3/05; H01S3/06; H01S3/063; H01S3/067; H01S3/0675; H01S3/09; H01S3/091; H01S3/094; H01S3/094003
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
197 words
A feedback, feedforward optical circuit having a
monitor tap comprising: a Bragg grating having a reflection band at a laser
wavelength λ L for reflecting no more than 10% of
light incident thereon backwards for providing
feedback, said Bragg grating being disposed in an
optical fiber having a core and a cladding, and wherein said Bragg grating has a reflection spectrum
having one or more side lobes adjacent the
reflection band of wavelengths for reflecting light
of a wavelength corresponding to the one or more
side lobes being different than the laser wavelength
λ L , said Bragg grating further having a blaze with
respect to an optical axis of the optical fiber, the
grating having a blaze angle that will direct less
than 5% of light incident thereon out of the optical
fiber through the cladding, said light having a
wavelength corresponding to a wavelength λ L , and the
grating having a transmission spectrum such that at
least 85% of light incident thereupon propagates
through the grating without reflecting backwards at
the wavelength λ L ; and a detector disposed to receive and detect light
directed out through the cladding for providing a
control signal.
Claim 2
Dependent Claim
25 words
A feedback, feedforward optical circuit as defined
in claim 1 further including a pump laser for
providing light having the laser wavelength λ L .
Claim 3
Dependent Claim
48 words
A feedback, feedforward optical circuit as defined
in claim 2 further including a control circuit for
receiving the control signal from the detector and
for providing the control signal to the pump laser
for at least one of monitoring and adjusting a power
level of the pump laser.
Claim 4
Dependent Claim
21 words
A feedback, feedforward optical circuit as defined
in claim 1 wherein the one or more side lobes are
obtained by apodization.
Claim 5
Dependent Claim
25 words
A feedback, feedforward optical circuit as defined
in claim 4 wherein the one or more side lobes are
contiguous with the wavelength λ L .
Claim 6
Dependent Claim
25 words
A feedback, feedforward optical circuit as defined
in claim 4 wherein the side lobes are enhanced by
generating a stitch error in the Bragg grating.
Claim 7
Dependent Claim
18 words
A feedback, feedforward optical circuit as defined
in claim 1, wherein the blaze angle is greater than
3°.
Claim 8
Dependent Claim
18 words
A feedback, feedforward optical circuit as defined
in claim 7, wherein the blaze angle is less than 15°.
Claim 9
Dependent Claim
18 words
A feedback, feedforward optical circuit as defined
in claim 8, wherein the blaze angle is substantially
about 6°.
Claim 10
Dependent Claim
28 words
A feedback, feedforward optical circuit as defined
in claim 8 wherein the blaze angle is greater than
or equal to 4° and less than or equal to 11°.
References Cited (Backward Citations)
No citation records indexed.
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