公开(公告)号：CA1250897A

公开(公告)日：1989-03-07

申请号：CA534179

申请日：1987-04-08

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CALVANI RICCARDO ,  CAPONI RENATO ,  CISTERNINO FRANCESCO

IPC: H04B10/00 ,  G02F2/00 ,  H04B10/02 ,  H04B10/04 ,  H04B10/06 ,  H04B10/135 ,  H04B10/142 ,  H04B10/152 ,  H04B10/18 ,  H04B9/00

Abstract: In an optical fibre transmission system with heterodyne coherent detection, the polarization of a transmitted optical carrier is modulated, and at a receiver the received modulated beam is combined with a beam emitted from a local oscillator, and split into two orthogonally polarized components. The two optical components are detected and sent to an electronic mixer which receives the two components and synchronously demodulates them, thus eliminating effects due to the line width of the source and of the local oscillator.

公开(公告)号：IT8467054D0

公开(公告)日：1984-01-20

申请号：IT6705484

申请日：1984-01-20

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CISTERNINO FRANCESCO

IPC: G01J3/12 ,  G01J3/18 ,  G01J3/28 ,  G02B

Abstract: The monochromator presents, in the plane of the slit (5), a mirror (6) which reflects the radiations comprised within the spectrum portion selected by the slit (5) towards the grating (3) dispersing a non-monochromatic beam. The radiations reflected recombine into a single, substantially monochromatic beam on the grating (3), and a suitable optical system (7, 8) focuses such a beam forming the substantially monochromatic image of the source (1).

公开(公告)号：IT1296646B1

公开(公告)日：1999-07-14

申请号：ITTO971097

申请日：1997-12-16

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CISTERNINO FRANCESCO ,  DE MARCHI ANDREA ,  GIRARDI RAFFAELE ,  ROEMISCH STEFANIA

IPC: H04B10/155 ,  H04J14/08 ,  G02F1/03 ,  H04L7/00

Abstract: The circuit includes an electro-optical mixer, such as an electro-optical Mach-Zehnder modulator (2), with non-linear behaviour. The modulator (2) receives as input an optical signal (Pin) at the frequency to be divided, in addition to an electric signal (e3) at a given frequency, usually corresponding to the frequency deriving from such division. The output optical signal (Pout) from modulator (2) exhibits a modulation spectrum containing the frequency difference between the frequency to be divided and at least one harmonic of the frequency of the above electric signal. After having been converted into an electric signal (e1), the output signal of the mixer is subjected to a filtering action (8) to extract the above frequency difference component. This latter one is then used both as electrical signal (e3) for the mixing, and as output signal from the divider (e2). The preferred application is to OTDM systems, to extract a synchronism signal at tributary signal frequency.

公开(公告)号：CA2150418A1

公开(公告)日：1995-12-01

申请号：CA2150418

申请日：1995-05-29

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： ARTIGLIA MASSIMO ,  CAPONI RENATO ,  CISTERNINO FRANCESCO ,  NADDEO CLAUDIO ,  ROCCATO DIEGO

IPC: G01M11/02 ,  G01M11/00 ,  G01N21/41 ,  G01N21/45

Abstract: To measure the nonlinear refractive index of an optical fibre, each pulse emitted by a source (L) is split into a pair of pulses which are sent in opposite directions into an optical-fibre Sagnac interferometric loop (AS) which includes the fibre under test (F). One of the pulses of the pair is attenuated before passing through the fibre (F) in such a way that only the other one has such a power as to induce nonlinear effects in the fibre (F). The interference between parts of pulses is analysed at the output of the loop (AS) and the nonlinear refractive index is derived from a measurement of the phase shift between the two pulses of the pair.

公开(公告)号：DE3564861D1

公开(公告)日：1988-10-13

申请号：DE3564861

申请日：1985-01-19

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CISTERNINO FRANCESCO

IPC: G01J3/12 ,  G01J3/18 ,  G01J3/28

Abstract: The monochromator presents, in the plane of the slit (5), a mirror (6) which reflects the radiations comprised within the spectrum portion selected by the slit (5) towards the grating (3) dispersing a non-monochromatic beam. The radiations reflected recombine into a single, substantially monochromatic beam on the grating (3), and a suitable optical system (7, 8) focuses such a beam forming the substantially monochromatic image of the source (1).

公开(公告)号：IT1195127B

公开(公告)日：1988-10-12

申请号：IT6764386

申请日：1986-08-08

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CALVANI RICCARDO ,  CAPONI RENATO ,  CISTERNINO FRANCESCO

IPC: G01J4/00 ,  G01J4/04 ,  G01J9/02 ,  G01J9/04 ,  G01N21/21 ,  H04B10/08 ,  G01J

Abstract: The interferometer makes use of an acousto-optic device (11, 21) to perform a frequency shift of the beam sent along one of the interferometer branches, so as to allow the determination of the state of polarization by heterodyne radiofrequency detection. The acousto-optic deuce can be inserted downstream the means (8) splitting the beam emitted by the source (1) into the two beams sent along the two interferometer branches, or it can also act as the beam splitter.

公开(公告)号：IT1179066B

公开(公告)日：1987-09-16

申请号：IT6783884

申请日：1984-08-22

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CALVANI RICCARDO ,  CAPONI RENATO ,  CISTERNINO FRANCESCO

IPC: G01J4/04 ,  G01J4/00 ,  G01J9/04 ,  G01N21/21 ,  G02B

Abstract: The method and the device are based on interference techniques. Two quasi-monochromatic radiations (2a, 2b; 102a, 102b; 202a, 202b) with slightly different optical frequencies are generated. A radiation is converted into a 45 DEG linearly-polarized radiation, while the other presents the polarization state imposed by a body under test (4, 204). In each radiation, horizontal and vertical polarization components are separated, and then recombined into two different beams (20a, 21a; 34, 35) comprising radiations at both frequencies, respectively polarized in the same plane. Beatings between the two components of each beam are originated and from the two electrical signals in the radio frequency range thus obtained the information is extracted on the relative phase and the amplitude of the two components of the radiation with polarization imposed by the body under test (4, 204).

公开(公告)号：CA1221851A

公开(公告)日：1987-05-19

申请号：CA472413

申请日：1985-01-18

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CISTERNINO FRANCESCO

IPC: G01J3/12 ,  G01J3/18 ,  G01J3/28 ,  G01N21/25

Abstract: A monochromator has a dispersing element such as a grating, and a slit to isolate a substantially monochromatic portion of source radiation dispersed by the element. In the plane of the slit is a mirror which reflects radiation comprised within the spectrum portion selected by the slit back towards the grating, so that the reflected radiation recombines into a single, substantially monochromatic beam on the grating, whereafter a suitable optical system focuses the beam to form a substantially monochromatic image of the source.

公开(公告)号：CA2256188C

公开(公告)日：2002-02-12

申请号：CA2256188

申请日：1998-12-15

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CISTERNINO FRANCESCO ,  DE MARCHI ANDREA ,  ROEMISCH STEFANIA ,  GIRARDI RAFFAELE

IPC: G02F1/03 ,  H04B10/155 ,  H04J14/08 ,  H04L7/00 ,  G02F2/02 ,  H04J14/02

Abstract: The circuit includes an electro-optical mixer, such as an electro-optical Mach-Zehnder modulator, with non-linear behaviour. The modulator receives as input an optical signal at the frequency to be divided, in addition to an electric signal at a given frequency, usually corresponding to the frequency deriving from such division. The output optical signal from modulator exhibits a modulation spectrum containing the frequency difference between the frequency to be divided and at least one harmonic of the frequency of the above electric signal. After having been converted into an electric signal, the output signal of the mixer is subjected to a filtering action to extract the above frequency difference component. This latter one is then used both as electrical signal for the mixing, and as output signal from the divider. The preferred application is to OTDM systems, to extract a synchronism signal at tributary signal frequency.

公开(公告)号：DE924552T1

公开(公告)日：2000-03-02

申请号：DE98123513

申请日：1998-12-15

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CISTERNINO FRANCESCO ,  DE MARCHI ANDREA ,  GIRARDI RAFFAELE ,  ROEMISCH STEFANIA

IPC: G02F1/03 ,  H04B10/155 ,  H04J14/08 ,  H04L7/00 ,  G02F1/35

Abstract: The circuit includes an electro-optical mixer, such as an electro-optical Mach-Zehnder modulator (2), with non-linear behaviour. The modulator (2) receives as input an optical signal (Pin) at the frequency to be divided, in addition to an electric signal (e3) at a given frequency, usually corresponding to the frequency deriving from such division. The output optical signal (Pout) from modulator (2) exhibits a modulation spectrum containing the frequency difference between the frequency to be divided and at least one harmonic of the frequency of the above electric signal. After having been converted into an electric signal (e1), the output signal of the mixer is subjected to a filtering action (8) to extract the above frequency difference component. This latter one is then used both as electrical signal (e3) for the mixing, and as output signal from the divider (e2). The preferred application is to OTDM systems, to extract a synchronism signal at tributary signal frequency.