公开(公告)号：JPH11139832A

公开(公告)日：1999-05-25

申请号：JP22520398

申请日：1998-07-27

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO ,  DAI GUOJUN ,  MOSSO SABRINA

IPC: C03B5/02 ,  C03B5/08 ,  F27D11/06

Abstract: PROBLEM TO BE SOLVED: To provide an improved induction electric furnace from which the temp. nonuniformity between different regions is removed. SOLUTION: The supporting device 6' for a crucible 3 of the glass synthesizing induction electric furnace and more particularly the induction electric furnace for fluorozirconate used in an fiber for communication is connected to a pair of sleeves 7, 9 and an annular element 8 constituting an actual supporting member is inserted therebetween. The first sleeve 7 has a such a size in a longitudinal direction that the crucible 3 is supported within this annular element 8 apart a specified spacing from a plane element 5'. The second sleeve has such a size in a longitudinal direction that the top end of the second sleeve exists at a level higher than the top end of the crucible so as to allow the existence of the temp. region uniform over at least the entire height of the crucible.

公开(公告)号：JPH10182188A

公开(公告)日：1998-07-07

申请号：JP32060197

申请日：1997-11-07

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO

IPC: G02B6/00 ,  C03B37/012 ,  C03B37/014 ,  C03B37/023 ,  C03B37/027 ,  C03C3/32 ,  C03C13/04 ,  H01S3/06 ,  H01S3/10

Abstract: PROBLEM TO BE SOLVED: To produce a single-mode active optical fiber capable of eliminating conventional defects and to provide a method for producing the optical fiber. SOLUTION: This single-mode active optical fiber has a core prepared from a nonoxide glass doped with a rare earth element and a clad prepared from an oxide glass. The melting temperature of the glass of the clad is lower than that of the glass of the clad and is within the range of the softening temperature of the clad. In a preferred embodiment, the core is prepared from a chalcogen compound glass and the clad is prepared from a silica lead glass. In order to prepare the fiber, an element prepared from the nonoxide glass is introduced into a hole 2 of a capillary 1 made of the oxide glass to thereby provide a preform, which is then drawn at a certain temperature within the range of the softening temperature of the oxide glass. The capillary 1 acts as a container for the molten glass of the core during the drawing step.

公开(公告)号：DE894771T1

公开(公告)日：1999-08-19

申请号：DE98114074

申请日：1998-07-28

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO ,  DAI GUOJUN ,  MOSSO SABRINA

IPC: C03B5/02 ,  C03B5/08 ,  F27D11/06 ,  H05B6/02

公开(公告)号：ITTO960927A1

公开(公告)日：1998-05-19

申请号：ITTO960927

申请日：1996-11-19

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO

IPC: G02B6/00 ,  C03B37/012 ,  C03B37/014 ,  C03B37/023 ,  C03B37/027 ,  C03C3/32 ,  C03C13/04 ,  H01S3/06 ,  H01S3/10

Abstract: An active single mode optical fiber has the core made of a rare earth doped non-oxide glass and the cladding made of an oxide glass. The glass of the core has a melting temperature lower than that of the glass of the cladding and lying within the range of the softening temperatures of the latter. In a preferred embodiment the core is made of a chalcogenide glass and the cladding is made of a lead silicate glass. To produce the fibre, a preform, obtained by introducing an element made of the non-oxide glass into the hole (2) of a capillary tube (1) made of the oxide glass, is brought to a temperature lying within the range of softening temperatures of the oxide glass and not lower than the melting temperature of the non-oxide glass, and is drawn. The capillary tube (1), during the drawing process, serves as a container for the molten glass of the core.

公开(公告)号：ITTO960927D0

公开(公告)日：1996-11-19

申请号：ITTO960927

申请日：1996-11-19

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO

IPC: G02B6/00 ,  C03B37/012 ,  C03B37/014 ,  C03B37/023 ,  C03B37/027 ,  C03C3/32 ,  C03C13/04 ,  H01S3/06 ,  H01S3/10

Abstract: An active single mode optical fiber has the core made of a rare earth doped non-oxide glass and the cladding made of an oxide glass. The glass of the core has a melting temperature lower than that of the glass of the cladding and lying within the range of the softening temperatures of the latter. In a preferred embodiment the core is made of a chalcogenide glass and the cladding is made of a lead silicate glass. To produce the fibre, a preform, obtained by introducing an element made of the non-oxide glass into the hole (2) of a capillary tube (1) made of the oxide glass, is brought to a temperature lying within the range of softening temperatures of the oxide glass and not lower than the melting temperature of the non-oxide glass, and is drawn. The capillary tube (1), during the drawing process, serves as a container for the molten glass of the core.

公开(公告)号：DE69202277T2

公开(公告)日：1995-09-21

申请号：DE69202277

申请日：1992-02-27

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO ,  COCITO GIUSEPPE ,  DE FRANCESCHI ROBERTO

IPC: G02B6/13 ,  G02B6/12

公开(公告)号：CA2142061A1

公开(公告)日：1995-09-17

申请号：CA2142061

申请日：1995-02-08

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO ,  COCITO GIUSEPPE

IPC: G02B6/00 ,  C03B37/012 ,  C03B37/014 ,  C03C13/04 ,  C03B37/023 ,  C03C25/06

Abstract: Fluoride glass optical fibres are fabricated by minimizing the number of high-temperature operations. A tube comprising an external layer of a first fluoride glass of composition suitable to form the cladding of the fibre and an internal layer of a second fluoride glass of composition suitable to form the core of the fibre is prepared from a melt by a conventional rotational casting technique. Then, the internal layer is thinned by means of chemical etching at ambient temperature until the attainment of a ratio between the volumes of the two layers that corresponds to the ratio between the core and cladding diameters required for a single mode fibre, and the resulting tube is drawn.

公开(公告)号：ITTO910136A1

公开(公告)日：1992-08-28

申请号：ITTO910136

申请日：1991-02-27

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO ,  COCITO GIUSEPPE ,  DE FRANCESCHI ROBERTO

IPC: G02B20060101 ,  G02B6/13

公开(公告)号：ITTO910136D0

公开(公告)日：1991-02-27

申请号：ITTO910136

申请日：1991-02-27

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO ,  COCITO GIUSEPPE ,  DE FRANCESCHI ROBERTO

IPC: G02B6/13 ,  G02B6/10

公开(公告)号：CA2221060C

公开(公告)日：2003-03-25

申请号：CA2221060

申请日：1997-11-14

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： BRAGLIA MARCO

IPC: G02B6/00 ,  C03B37/012 ,  C03B37/014 ,  C03B37/023 ,  C03B37/027 ,  C03C3/32 ,  C03C13/04 ,  H01S3/06 ,  H01S3/10 ,  G02B6/16 ,  C03B37/075 ,  H04B10/17

Abstract: An active single mode optical fiber has the core made of a rare earth doped non-oxide glass and the cladding made of an oxide glass. The glass of the core has a melting temperature lower than that of the glass of the cladding and lying within th e range of the softening temperatures of the latter. In a preferred embodiment the pore is made of a chalcogenide glass and the cladding is made of a lead silicate glass. To produce the fibre, a preform , obtained by introducing an element made of the non-oxide glass into the hole of a capillary tube made of the oxide glass, is brought to a temperature lying within the range of softening temperatures of the oxide glass and not lower than the melting temperature of the non-oxide glass, and is drawn. The capillary tube (1), during the drawing process, serves as a container for the molten glass of the core.