公开(公告)号：EP1272824B1

公开(公告)日：2004-09-22

申请号：EP01914922.8

申请日：2001-03-30

Applicant: EXFO ELECTRO-OPTICAL ENGINEERING INC.

Inventor： BABIN, François ,  CYR, Normand

IPC: G01J9/02 ,  G01M11/00

CPC classification number: G01M11/333 ,  G01J9/02 ,  G01M11/338

公开(公告)号：EP1272824A1

公开(公告)日：2003-01-08

申请号：EP01914922.8

申请日：2001-03-30

Applicant: EXFO ELECTRO-OPTICAL ENGINEERING INC.

Inventor： BABIN, François ,  CYR, Normand

IPC: G01J9/02 ,  G01M11/00

CPC classification number: G01M11/333 ,  G01J9/02 ,  G01M11/338

Abstract: In order to avoid errors inherent in the measurement of electrical phase differences or pulse arrival time in relative group delay measurements, different optical signals have their intensity modulated at a common high frequency and different permutations are selected. The amplitudes of corresponding electrical signals are detected and phase differences are computed on the basis of trigonometrical relationships. Because the modulation frequency is known, time differences can be deduced. Apparatus for measuring the phase differences conveniently comprises a slotted wheel which passes selected ones or both of the optical signals. One of the optical signals may be split to produce a third signal with a predetermined phase shift, e.g. about 90 degrees at the modulation frequency and the amplitudes of some possible permutations of the three optical signals used to compute the phase difference. The measurements may be used to compute chromatic dispersion, polarization mode dispersion, elongation, and so on.

公开(公告)号：EP2140243A1

公开(公告)日：2010-01-06

申请号：EP08733675.6

申请日：2008-03-28

Applicant: EXFO ELECTRO-OPTICAL ENGINEERING INC.

Inventor： CYR, Normand ,  CHEN, Hongxin

IPC: G01M11/02 ,  H01S3/067 ,  H01S3/082 ,  H01S3/23 ,  H01S5/026 ,  H01S5/10

CPC classification number: G01M11/336 ,  G01M11/335

Abstract: A method and apparatus for measuring at least one polarization-related characteristic of an optical path (FUT) uses a light input unit connected to the FUT at or adjacent a proximal end of the FUT and a light output unit connected to the FUT at or adjacent its proximal or distal end. The light input unit injects into the FUT at least partially polarized light having a controlled state of polarization (I-SOP). The output light unit extracts corresponding light from the FUT, analyzes and detects the extracted light corresponding to at least one transmission axis (A-SOP), and processes the corresponding electrical signal to obtain transmitted coherent optical power at each wavelength of light in each of at least two groups of wavelengths, wherein the lowermost (λ1) and uppermost (λu) said wavelengths in each said group of wavelengths are closely- spaced. A processing unit than computes at least one difference in a measured power parameter corresponding to each wavelength in a wavelength pair for each of the at least two groups, the measured power parameter being proportional to the power of the said analyzed and subsequently detected light, thereby defining a set of at least two measured power parameter differences; computes the mean-square value of said set of differences; and calculating the at least one polarization-related FUT characteristic as at least one predetermined function of said mean-square value, the predetermined function being dependent upon the small optical frequency difference between the wavelengths corresponding to the said each at least said two pairs of closely-spaced wavelengths.

公开(公告)号：EP1673881B1

公开(公告)日：2009-06-10

申请号：EP04761716.2

申请日：2004-08-23

Applicant: EXFO ELECTRO-OPTICAL ENGINEERING INC.

Inventor： RUCHET, Bernard

IPC: H04B10/08 ,  H04B17/00

CPC classification number: H04B10/07955 ,  H04B3/46 ,  H04B10/079 ,  H04B10/0793 ,  H04B10/0795 ,  H04B10/07953 ,  H04Q11/0067 ,  H04Q2011/0083

Abstract: An instrument for measuring bidirectional optical signals propagating in an optical transmission path between elements one of which will not transmit if continuity of the transmission path is not maintained, for example a branch path between a central offices optical line terminal (OLT) and an end-user's optical network terminal (ONT), comprises first and second connector receptacles for connecting the instrument into the path, a 2x2 coupler ( 32 ) having first and second ports ( 28, 30 ) connected to the first and second connectors ( 22, 24 ), respectively, for completing the optical transmission path, a third port ( 36 ) for, outputting a portion of each optical signal received via the first port ( 28 ) and a fourth port ( 34 ) for outputting a portion of each optical signal received via the second port ( 30 ) Detectors ( 38, 42, 44 ) coupled to the third and fourth ports convert the optical signal portions into corresponding electrical signals, which are processed to provide the desired measurements. The measurement results may be displayed by a suitable display unit ( 60 ) Where the ÖLT transmits signals at two different wavelengths, the instrument may separate parts of the corresponding optical signal portion according to wavelength and process them separately.

公开(公告)号：EP1952561A1

公开(公告)日：2008-08-06

申请号：EP06790880.6

申请日：2006-10-24

Applicant: EXFO ELECTRO-OPTICAL ENGINEERING INC.

Inventor： PERRON, Stéphane ,  RUCHET, Bernard ,  LEBLANC, Michel

IPC: H04B10/08 ,  G01M11/00

CPC classification number: G02B6/4482 ,  G01M11/3136 ,  H04B10/071

Abstract: Ih order to simplify and expedite identification of fibers (DF 1/1,..., DF2/4) in multi-fiber cables (DFl1 DF2), a method of identifying each of a plurality of fibers includes the steps of launching light into each of the fibers using an OTDR and applying a unique signature to each resulting OTDR trace by means of signature-applying means (EB) connected to a distal end of the fibers. The resulting plurality of OTDR traces have different signatures, enabling identification of each of the fibers by detecting its signature in the corresponding OTDR trace.

公开(公告)号：EP1252489B1

公开(公告)日：2003-12-17

申请号：EP01900347.4

申请日：2001-01-04

Applicant: EXFO ELECTRO-OPTICAL ENGINEERING INC.

Inventor： HE, Gang ,  GARIEPY, Daniel ,  SCHINN, Gregory, Walter

IPC: G01J3/12 ,  G01J4/02 ,  G01J3/447

CPC classification number: G01J3/12 ,  G01J3/447 ,  G01J4/02

Abstract: An optical spectrum analyzer comprises a diffraction grating (DG), a polarization decomposing unit (PDM) for decomposing the input light beam into first and second light beams having mutually-perpendicular linear states of polarization, and two output ports (FP2/1, FP2/2) each for receiving from the grating, substantially exclusively, a respective one of the polarized light beams (LT, LR) after diffraction by the diffraction grating (DG). Each of the linearly-polarized light beams is directed onto the diffraction grating with its linear state of polarization at any prescribed angle to a corresponding plane of diffraction of the diffraction grating. The arrangement is such that the state of polarization of the light beams, at any particular wavelength within an operating band of the analyzer remains substantially unchanged with respect to time. The analyzer also may have a reflector (RAM) for reflecting the light beams leaving the diffraction grating after diffraction a first time so as to return them to the diffraction grating for diffraction a second time.

公开(公告)号：EP1590646A1

公开(公告)日：2005-11-02

申请号：EP03700784.6

申请日：2003-02-06

Applicant: EXFO ELECTRO-OPTICAL ENGINEERING INC.

Inventor： CYR, Normand

IPC: G01M11/00

CPC classification number: G01J4/04 ,  G01M11/331 ,  G01M11/336

Abstract: Apparatus for measuring polarization mode dispersion (PMD) of adevice, e. g. a waveguide, comprises a broadband light source (10,12) for passing polarized broadband light through the device (14), an interferometer (20) for dividing and recombining light that has passed through the device to form interferograms, a polarization separator (30) for receiving the light from the interferometer and separating such received light along first and second orthogonalFebruary 25, 2003February 25, 2003 polarization states, detectors (32x,32y) for converting the first and second orthogonal polarization states, respectively, into corresponding first and second electrical signals (Px(τ),Py(τ)), and a processor (36) for computing the modulus of the difference and such, respectively, of the first and second electrical signals to produce a cross-correlation envelope (EC(τ)) and an auto-correlation envelope (Ec(τ)), and determining the polarization mode dispersion according to the expression PMD = where and τ is the delay difference between the paths of the interferometer.

公开(公告)号：EP1252489A2

公开(公告)日：2002-10-30

申请号：EP01900347.4

申请日：2001-01-04

Applicant: EXFO ELECTRO-OPTICAL ENGINEERING INC.

Inventor： HE, Gang ,  GARIEPY, Daniel ,  SCHINN, Gregory, Walter

IPC: G01J3/12 ,  G01J4/02 ,  G01J3/447

CPC classification number: G01J3/12 ,  G01J3/447 ,  G01J4/02

Abstract: An optical spectrum analyzer comprises a diffraction grating (DG), a polarization decomposing unit (PDM) for decomposing the input light beam into first and second light beams having mutually-perpendicular linear states of polarization, and two output ports (FP2/1, FP2/2) each for receiving from the grating, substantially exclusively, a respective one of the polarized light beams (LT, LR) after diffraction by the diffraction grating (DG). Each of the linearly-polarized light beams is directed onto the diffraction grating with its linear state of polarization at any prescribed angle to a corresponding plane of diffraction of the diffraction grating. The arrangement is such that the state of polarization of the light beams, at any particular wavelength within an operating band of the analyzer remains substantially unchanged with respect to time. The analyzer also may have a reflector (RAM) for reflecting the light beams leaving the diffraction grating after diffraction a first time so as to return them to the diffraction grating for diffraction a second time.