This application relates generally to an optical fiber for the delivery of infrared light where the polarization state of the light entering the fiber is preserved upon exiting the fiber and the related methods for making thereof. The optical fiber has a wavelength between about 0.9 ?m and 15 ?m, comprises at least one infrared-transmitting glass, and has a polarization-maintaining (PM) transverse cross-sectional structure. The infrared-transmitting, polarization-maintaining (IR-PM) optical fiber has a birefringence greater than 10.sup.?5 and has applications in dual-use technologies including laser power delivery, sensing and imaging.

This application relates generally to an optical fiber for the delivery of infrared light where the polarization state of the light entering the fiber is preserved upon exiting the fiber and the related methods for making thereof. The optical fiber has a wavelength between about 0.9 ?m and 15 ?m, comprises at least one infrared-transmitting glass, and has a polarization-maintaining (PM) transverse cross-sectional structure. The infrared-transmitting, polarization-maintaining (IR-PM) optical fiber has a birefringence greater than 10.sup.?5 and has applications in dual-use technologies including laser power delivery, sensing and imaging.

A method for co-finishing surfaces bonds a first structure formed of a first material and having a first surface in an aperture defined in a second structure formed of a second material and having a second surface such that there is an offset between the first surface and the second surface. The first surface and the second surface are co-lapped to reduce the offset. The first surface and second surface are co-polished to further reduce the offset. The first surface and second surfaces may then be flush. Edges of the first surface may be chamfered to mitigate damage during co-lapping and/or co-polishing. Fill material may be positioned in gaps between the first and second structures to mitigate damage during co-lapping and/or co-polishing.

A method for co-finishing surfaces bonds a first structure formed of a first material and having a first surface in an aperture defined in a second structure formed of a second material and having a second surface such that there is an offset between the first surface and the second surface. The first surface and the second surface are co-lapped to reduce the offset. The first surface and second surface are co-polished to further reduce the offset. The first surface and second surfaces may then be flush. Edges of the first surface may be chamfered to mitigate damage during co-lapping and/or co-polishing. Fill material may be positioned in gaps between the first and second structures to mitigate damage during co-lapping and/or co-polishing.

The invention relates to a device for processing optical fibers, comprising: a pair of pulleys (1, 2) arranged to receive in a space between them a first optical fiber element (4), and a drive mechanism. In order to obtain a device capable of efficiently and reliably processing optical fibers the first pulley (1) in the pair of pulleys comprises a circumferential first groove (5) in a circumferential contact surface (6) for receiving the first optical fiber element (4), the first groove (5) being shaped to accommodate the first optical fiber element (4) such that less than half of the cross sectional surface area of the first optical fiber element (4) protrudes out of the first groove (5), and a second pulley (2) in the pair of pulleys comprises a circumferential contact surface (7) contacting a surface of the first optical fiber element (4).

The invention relates to a device for processing optical fibers, comprising: a pair of pulleys (1, 2) arranged to receive in a space between them a first optical fiber element (4), and a drive mechanism. In order to obtain a device capable of efficiently and reliably processing optical fibers the first pulley (1) in the pair of pulleys comprises a circumferential first groove (5) in a circumferential contact surface (6) for receiving the first optical fiber element (4), the first groove (5) being shaped to accommodate the first optical fiber element (4) such that less than half of the cross sectional surface area of the first optical fiber element (4) protrudes out of the first groove (5), and a second pulley (2) in the pair of pulleys comprises a circumferential contact surface (7) contacting a surface of the first optical fiber element (4).

A coupled-core multi-core fiber in which an inter-core distance is stabilized is manufactured. A method of manufacturing a coupled-core multi-core fiber includes forming a second cladding base material by depositing glass particulates on an outer periphery of a first cladding base material and sintering the glass particulates. The first cladding base material has a hydroxyl group concentration that is less than or equal to 10 ppb; obtaining a ground rod by grinding an outer periphery of the second cladding base material; and forming holes in the first cladding base material in the ground rod, inserting a core base material into each of the holes, and obtaining an assembly.

A coupled-core multi-core fiber in which an inter-core distance is stabilized is manufactured. A method of manufacturing a coupled-core multi-core fiber includes forming a second cladding base material by depositing glass particulates on an outer periphery of a first cladding base material and sintering the glass particulates. The first cladding base material has a hydroxyl group concentration that is less than or equal to 10 ppb; obtaining a ground rod by grinding an outer periphery of the second cladding base material; and forming holes in the first cladding base material in the ground rod, inserting a core base material into each of the holes, and obtaining an assembly.

An object of the present disclosure is to provide an optical multiplexing/demultiplexing circuit manufacturing device and an optical multiplexing/demultiplexing circuit manufacturing method for polishing a portion of a side surface of an optical fiber core wire by a desired polishing amount without measuring optical loss by cutting an active optical fiber core wire.

To achieve the object described above, the optical multiplexing/demultiplexing circuit manufacturing device according to the present disclosure includes: an optical fiber core wire holding unit having a groove in which a portion of a side surface of an optical fiber core wire is embedded so as to protrude from an open plane by a predetermined distance; a polishing unit in which a polishing flat surface facing the open plane in parallel polishes the portion of the side surface of the optical fiber core wire; and a control unit that causes the polishing unit to start polishing the portion of the side surface of the optical fiber core wire and to finish polishing when the polishing flat surface of the polishing unit reaches the open plane.

An object of the present disclosure is to provide an optical multiplexing/demultiplexing circuit manufacturing device and an optical multiplexing/demultiplexing circuit manufacturing method for polishing a portion of a side surface of an optical fiber core wire by a desired polishing amount without measuring optical loss by cutting an active optical fiber core wire.

To achieve the object described above, the optical multiplexing/demultiplexing circuit manufacturing device according to the present disclosure includes: an optical fiber core wire holding unit having a groove in which a portion of a side surface of an optical fiber core wire is embedded so as to protrude from an open plane by a predetermined distance; a polishing unit in which a polishing flat surface facing the open plane in parallel polishes the portion of the side surface of the optical fiber core wire; and a control unit that causes the polishing unit to start polishing the portion of the side surface of the optical fiber core wire and to finish polishing when the polishing flat surface of the polishing unit reaches the open plane.