Patent US2165996A successfully refreshed from Google Patents.
US4378490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical attenuator providing controlled attenuation
Assignee: Thales SA
•
Filing: 1980-11-18
•
Granted: 1983-03-29
•
Expires: 2000-11-18
Abstract
Abstract The real attenuation produced by the optical attenuator is determined by means of photodetectors which carry out continuous measurement of the intensity of an auxiliary beam before and after it passes through the attenuator element. Signals which are emitted by the photodetectors and are proportional to the intensity received are transmitted to an electronic processing system which computes and displays the attenuation in decibels.
Inventors
- 👤 D'auria Luigi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:26
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/0121
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
108 words
An optical attenuator system providing controlled attenuation and comprising an attenuator element interposed on the path of a principle light beam, and a control input for adjusting the attenuation, wherein the attenuation produced by the attenuator element is continuously detected by an auxiliary optical system which is optically coupled to said attenuator element, wherein said auxiliary optical comprises an auxiliary light source and means for forming an auxiliary beam and measuring the intensity of said auxiliary beam both upstream and downstream of the attenuator element, and wherein an electronic processing system receives the signals delivered by said auxiliary optical system in order to generate an attenuation control signal.
Claim 2
Dependent Claim
108 words
An optical attenuator system providing controlled attenuation and comprising an attenuator element interposed on the path of a principle light beam, and a control input for adjusting the attenuation, wherein the attenuation produced by the attenuator element is continuously detected by an auxiliary optical system which is optically coupled to said attenuator element, wherein said auxiliary optical comprises an auxiliary light source and means for forming an auxiliary beam and measuring the intensity of said auxiliary beam both upstream and downstream of the attenuator element, and wherein an electronic processing system receives the signals delivered by said auxiliary optical system in order to generate an attenuation control signal.
Claim 3
Dependent Claim
15 words
An attenuator system according to claim 1, wherein the beam to be attenuated is parallel.
Claim 4
Dependent Claim
49 words
An attenuator system according to claim 1, wherein the light intensities collected before and after attenuation are collected on two photodetectors which deliver measurement signals, said signals being processed by an electronic system and the value of attenuation in decibels being provided directly at the output of said system.
Claim 5
Dependent Claim
19 words
An attenuator system according to claim 3, wherein collections of intensity are carried out by means of semitransparent plates.
Claim 6
Dependent Claim
39 words
An attenuator system according to claim 1, wherein the light intensity of the auxiliary beam upstream of the attenuator element is measured on a predetermined fraction of said beam, reflected from a semitransparent plate and collected on a photodetector.
Claim 7
Dependent Claim
35 words
An attenuator according to claim 1, wherein the auxiliary source is an integrated device element which further comprises a photodetector for determining at each instant the intensity of the auxiliary beam delivered by said element.
Claim 8
Dependent Claim
31 words
An attenuator system according to claim 5 or claim 6, wherein the intensity of the auxiliary light beam downstream of the attenuator element is measured by means of a second photodetector.
Claim 9
Dependent Claim
37 words
An attenuator system according to claim 5, wherein the photodetectors deliver measurement signals, said signals being processed by an electronic system and the value of attenuation in decibels being provided directly at the output of said system.
Claim 10
Dependent Claim
13 words
An attenuator system according to claim 8, wherein the auxiliary beam is parallel.
Claim 11
Dependent Claim
31 words
An attenuator system according to claim 9, wherein the principal beam and the auxiliary beam pass through the attenuator element in two separate and distinct regions corresponding to substantially equal attenuations.
Claim 12
Dependent Claim
20 words
An attenuator system according to claim 9, wherein the two beams pass through the attenuator element in the same region.
Claim 13
Dependent Claim
21 words
An attenuator system according to claim 11, wherein the two beams pass through the attenuator element at different angles of incidence.
Claim 14
Dependent Claim
78 words
An attenuator system according to claim 11, wherein the two beams of different wavelengths are superimposed on a limited portion of path which includes the attenuator element, said superimposition being obtained by means of two mirrors which are placed on each side of said attenuator element and at least one of which is dichroic, said mirrors being interposed on the path of the principal beam in order to separate the auxiliary beam from said principal beam after attenuation.
Claim 15
Dependent Claim
18 words
An attenuator system according to claim 13, wherein the mirror located upstream of the attenuator element is semitransparent.
Claim 16
Dependent Claim
40 words
An attenuator system according to claim 1, wherein said control input of attenuator element is controlled by a comparator which receives a reference value at one input and receives at the other input the value delivered by the signal-processing system.
Claim 17
Dependent Claim
24 words
An attenuator system according to claim 1, further comprising an optical coupling means for using said attenuator system in an optical fiber transmission circuit.
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) | 1986-03-28 | 1986-09-27 | 1987-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-28 | 1990-09-27 | 1991-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-28 | 1994-09-27 | 1995-03-29 | $7700.00 | Window Closed / Lapsed |