US5202745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polarization independent optical coherence-domain reflectometry
Assignee: Agilent Technologies Inc
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Filing: 1992-03-02
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Granted: 1993-04-13
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Expires: 2012-03-02
Abstract
Abstract An optical coherence-domain reflectometry system provides an interferometer driven by a broadband incoherent light source with the device under test connected to one arm of the interferometer and a movable scanning mirror in the other arm providing a reference signal. The mirror moves at a controlled velocity to produce a Doppler shift in the reference signal frequency. The reference signal arm also includes a piezoelectric transducer which modulates the phase of the reference signal at a given frequency, causing a further shift in the reference signal frequency. The interference signal is detected and measured by a polarization diversity receiver. A linear polarizer in the reference signal arm is adjusted to produce equal reference signal powers in each arm of the polarization diversity receiver in the absence of a reflection signal from the test arm. The measured reflectometry signal is substantially independent of the state of polarization of the reflected signal from the device under test.
Inventors
- 👤 Wayne V. Sorin
- 👤 Brian L. Heffner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:49
CPC Classifications
G; G01; G01M; G01M11/00; G01M11/30; G01M11/31; G01M11/3172; G01B; G01B9/00; G01B9/02; G01B9/02001; G01B9/02002; G01B9/02055; G01B9/0207; G01B9/02072; G01B9/0209; G01M11/3181; G01B2290/00; G01B2290/45; G01B2290/70
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
124 words
An optical reflectometer for measuring an optical parameter of a device under test, the reflectometer comprising: means for providing a broadband reference signal; means for applying a broadband test signal to a device under test and receiving a response signal from said device; a plurality of optical sensors responsive to optical signals of differing polarities for receiving the reference and response signals; polarization control means for controlling the polarization of the reference signal to balance the sensor responses; and output means responsive to the sensors for providing an output signal indicative of an optical parameter of the device under test, the output signal being substantially independent of polarization in the response signal when the sensor responses have been balanced by the polarization control means.
Claim 2
Dependent Claim
124 words
An optical reflectometer for measuring an optical parameter of a device under test, the reflectometer comprising: means for providing a broadband reference signal; means for applying a broadband test signal to a device under test and receiving a response signal from said device; a plurality of optical sensors responsive to optical signals of differing polarities for receiving the reference and response signals; polarization control means for controlling the polarization of the reference signal to balance the sensor responses; and output means responsive to the sensors for providing an output signal indicative of an optical parameter of the device under test, the output signal being substantially independent of polarization in the response signal when the sensor responses have been balanced by the polarization control means.
Claim 3
Dependent Claim
28 words
A reflectometer as in claim 1 wherein; the polarization control means comprises a linear polarizer; the reference signal is substantially unpolarized; and the test signal is substantially unpolarized.
Claim 4
Dependent Claim
15 words
A reflectometer as in claim 1 wherein the polarization control means comprises a birefringent waveplate.
Claim 5
Dependent Claim
19 words
An optical reflectometer as in claim 1 further comprising phase-controlling means to change the phase of the reference signal.
Claim 6
Dependent Claim
161 words
An optical reflectometer for measuring an optical parameter of a device under test, the reflectometer comprising: an interferometer having a light source for providing a beam of broadband light, means for dividing the beam of light into a reference signal and a test signal, means for applying the test signal to a device under test and receiving a response signal from said device, and means for combining the reference and response signals; a polarization diversity receiver having a plurality of optical sensors responsive to optical signals of differing polarities for receiving the combined reference and response signals; polarization control means for controlling the polarization of the reference signal to balance the sensor responses; and means in the receiver responsive to the sensors for providing an output signal indicative of an optical parameter of the device under test, the output signal being substantially independent of polarization in the response signal when the sensor responses have ben balanced by the polarization control means.
Claim 7
Dependent Claim
161 words
An optical reflectometer for measuring an optical parameter of a device under test, the reflectometer comprising: an interferometer having a light source for providing a beam of broadband light, means for dividing the beam of light into a reference signal and a test signal, means for applying the test signal to a device under test and receiving a response signal from said device, and means for combining the reference and response signals; a polarization diversity receiver having a plurality of optical sensors responsive to optical signals of differing polarities for receiving the combined reference and response signals; polarization control means for controlling the polarization of the reference signal to balance the sensor responses; and means in the receiver responsive to the sensors for providing an output signal indicative of an optical parameter of the device under test, the output signal being substantially independent of polarization in the response signal when the sensor responses have ben balanced by the polarization control means.
Claim 8
Dependent Claim
26 words
A reflectometer as in claim 5 wherein; the polarization control means comprises a linear polarizer; and the beam provided by the light source is substantially unpolarized.
Claim 9
Dependent Claim
24 words
A reflectometer as in claim 5 wherein the light source comprises a polarized light source and the polarization control means comprises a birefringent waveplate.
Claim 10
Dependent Claim
19 words
An optical reflectometer as in claim 5 further comprising phase-controlling means to change the phase of the reference signal.
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) | 1996-04-12 | 1996-10-12 | 1997-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-12 | 2000-10-12 | 2001-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-12 | 2004-10-12 | 2005-04-13 | $7700.00 | Window Closed / Lapsed |