Browse Prior Art Database

Active Alignment And Measuring Tool for Fiber-Optic Laser Subassemblies

IP.com Disclosure Number: IPCOM000101846D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Lang, RW: AUTHOR [+4]

Abstract

Disclosed is a tool capable of providing active submicron alignment of a laser in its fiber-optic transmitter subassembly and its absolute position after welding.

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This is the abbreviated version, containing approximately 76% of the total text.

Active Alignment And Measuring Tool for Fiber-Optic Laser Subassemblies

       Disclosed is a tool capable of providing active submicron
alignment of a laser in its fiber-optic transmitter subassembly and
its absolute position after welding.

      The current practice for assembling fiber-optic subassemblies
relies on maximizing the laser power coupled to a "master cable".  In
general, this master cable is a nominally dimensioned connector
ferrule containing a centered 10-micron single-mode fiber.
Measurements have shown that the laser spot can be as much as 3
microns offset from the mechanical axis of the subassembly using this
technique.  This uncertainty, coupled with the dimensional tolerances
of a population of connectorized cables and the offset introduced by
the welding operation, can result in total fiber core-to-laser spot
offsets approaching 6 microns and hence undesirable power coupling
variations.

      The disclosed tool combines the technology of a Coordinate
Measuring Machine (CMM) and a light-seeking fiber.  The CMM consists
of a computer-controlled arm which supports a piezoelectric crystal
sensor (a spherical ruby whose diameter is known to 0.0025 um).  The
arm is capable of moving in 0.3 um increments.  A 10-um single-mode
fiber is located in the center of the piezoelectric sensor (a slight
offset can be calibrated).  The tool can be used to measure the
transmitter subassembly bore diameter and locate the sensor at the
mechanical cent...