公开(公告)号：CA1072789A

公开(公告)日：1980-03-04

申请号：CA271328

申请日：1977-02-08

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： DI VITA PIETRO ,  VANNUCCI RICCARDO

IPC: G02B6/14 ,  G02B6/26 ,  G02B6/34 ,  G02B5/14

Abstract: A mode delay equalizer for optical waveguides which achieves an improved equalization factor and/or reduced signal loss comprises at least one mirror having a cross-section which is a segment of an ellipse disposed so as to reflect rays from the end of one waveguide segment into the end of a second waveguide segment, the elliptical segment or segments having its or their focuses at the ends of the waveguide segments.

公开(公告)号：CA1069359A

公开(公告)日：1980-01-08

申请号：CA273270

申请日：1977-03-07

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： DI VITA PIETRO

IPC: G02B3/02 ,  G02B6/14 ,  G02B3/08 ,  G02B5/14

Abstract: A lens type optical mode delay equalizer for multimode optical waveguides requires only two parallel lenses as equalizing elements, these lenses each having a cross section corresponding to that which would be formed by cutting away parts of two identical converging lenses by cuts parallel to their optical axes, and joining the remaining portions at the cuts. The parallel lenses are spaced between the ends of two lengths of waveguide in accosdance with a relationship involving various parameters of the lenses and the separation and maximum angle of propagation of the waveguide. Practical lens configurations may be toroidal or cushioncuspidal for circular waveguides and bicylindrical or cuspidal for ribbon waveguides.

公开(公告)号：CA1306854C

公开(公告)日：1992-09-01

申请号：CA582411

申请日：1988-11-07

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： DI VITA PIETRO

IPC: G02B6/00 ,  C03B37/14 ,  C03B37/15 ,  G02B6/02 ,  C03B37/10 ,  G02B6/16

Abstract: A silica glass optical fibre is submitted to ultrasonic vibration such as to cause atoms of the vitreous matrix to stabilize in a lower energy condition. Preferably the fibre is heated to near its softening point and then cooled during vibration. In this way, inhomogeneity domain sizes and thus the attenuation due to Rayleigh scattering are reduced.

公开(公告)号：DE3684097D1

公开(公告)日：1992-04-09

申请号：DE3684097

申请日：1986-11-12

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CAPONI RENATO ,  COPPA GIANNI ,  DI VITA PIETRO

IPC: G01M11/02 ,  G01M11/00 ,  G02B6/00

Abstract: The method of measuring mode field radius in single-mode optical fibres comprises the modulation of an optical beam by means of a spatial filter with radial-distribution of transmittivity of Gaussian type. Modulated beam intensity is measured in correspondence with the beam axis for different widths of the Gaussian curve, and the mode field radius is derived from both such intensity values and a parameter dependant on the Gaussian width. The apparatus which implements the method is also provided.

公开(公告)号：DE3583926D1

公开(公告)日：1991-10-02

申请号：DE3583926

申请日：1985-12-09

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： COPPA GIANNI ,  DI VITA PIETRO

IPC: G01J1/00 ,  G01J1/02 ,  G01J1/42 ,  G01J4/00 ,  G01M11/00 ,  G01R29/08

Abstract: A method and an apparatus are provided wherein a light beam is passed through a slit (7) oscillating with respect to the beam, and a periodic signal is obtained from the beam portion traversing the slit and is split into its spectral components. Moment values are derived from the values of the amplitudes of such components.

公开(公告)号：DE3675992D1

公开(公告)日：1991-01-17

申请号：DE3675992

申请日：1986-04-16

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： CALZAVARA MASSIMO ,  COPPA GIANNI ,  DI VITA PIETRO

IPC: G02B6/24 ,  G01M11/00

Abstract: An optical beam is injected into a single-mode (FO) fibre of a given length and outgoes from an end face of the fibre, is reflected by a reflecting optical system into said fibre; the optical power of the reflected beam guided backward by the fibre is measured. Said end face of the fibre is placed in the optical centre of the reflecting system to obtain the maximum reflected power, and is then deviated from said position detecting the occurring reductions of the reflected optical power.A device and variants to implement the method are also described.

公开(公告)号：DE3573019D1

公开(公告)日：1989-10-19

申请号：DE3573019

申请日：1985-06-03

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： COPPA GIANNI ,  DI VITA PIETRO

IPC: G01M11/00 ,  G01M11/02 ,  G01M11/08

Abstract: The process is based on the fact that the introduction of perturbations in an optical fibre can generate greater losses on higher order modes. Therefore, a spectral scanning of the fibre output power is effected under a certain number of different perturbation conditions and the values obtained are combined so as to determine the fraction of power guided in the fundamental mode. The cut-off wavelength is that where this fraction exceeds a certain value. The equipment implementing the process is also provided.

公开(公告)号：IT1179877B

公开(公告)日：1987-09-16

申请号：IT6825684

申请日：1984-12-18

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： COPPA GIANNI ,  DI VITA PIETRO

IPC: G01M11/02 ,  G01M11/00 ,  G01N21/41 ,  G02B6/00 ,  G01N

公开(公告)号：AT25290T

公开(公告)日：1987-02-15

申请号：AT83105581

申请日：1983-06-07

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： COPPA GIANNI ,  DI VITA PIETRO ,  POTENZA MARCELLO ,  ROSSI UMBERTO

IPC: G01M11/02 ,  G01N21/41 ,  G02B6/00

公开(公告)号：IT1156947B

公开(公告)日：1987-02-04

申请号：IT6778178

申请日：1978-04-10

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： DI VITA PIETRO

IPC: G02B20060101 ,  G02B