摘要:
Defects in optical fibers are detected during manufacturing by using three bandpass filters to separate signals from a scattered light signal produced by a light source in a fiber measurement system. The separated signals include a clad diameter signal, a regular airline signal and a core airline signal. The regular airline signal is compared with the clad diameter signal to produce a normalized regular airline signal, and the core airline signal is compared with the clad diameter signal to produce a normalized core airline signal. The normalized regular airline signal and normalized core airline signal are monitored to determine if they increase, which indicates the presence of a defect in the optical fiber.
摘要:
Methods and apparatuses negate a measured mechanical twist of an optical fiber by introducing a counteracting twist to bring the net mechanical twist closer to zero, which reduces the fiber's polarization mode dispersion (PMD). A spool of optical fiber having undesirable mechanical twist is mounted and fiber is drawn from the end of the spool to impart a specified counteracting mechanical twist. Additionally, the spool may be controllably rotated by a control system while optical fiber is drawn there from, allowing the system to generate a precise amount of counteracting mechanical twist in the fiber.
摘要:
Methods and apparatuses estimate and control optical fiber primary coating diameter for wet-on-wet optical fiber manufacturing. The primary coating diameter for a particular length of optical fiber is calculated based upon a measurement of the weight of primary and/or secondary coating material consumed during optical fiber manufacturing. Control of the primary coating diameter is effected by a coating controller which can increase or decrease the primary coating diameter through control of glass temperature, coating viscosity and/or other parameters during wet-on-wet fiber manufacture.
摘要:
Methods for modifying preform core ovality during and subsequent to the formation of an optical fiber preform. After MCVD deposition forms the core rod, but prior to overcladding of the core rod, the code rod may be etched to change its ovality. In order to etch the core rod, the core rod may be mounted to lathe, rotated by at least two rotors, and subjected to a heat source. Additionally, one of the at least two rotors may be phase-shifted from another one of the at least two rotors after the core rod is mounted on the lathe.
摘要:
Methods for modifying preform core ovality during and subsequent to the formation of an optical fiber preform. After MCVD deposition forms the core rod, but prior to overcladding of the core rod, the code rod may be etched to change its ovality. In order to etch the core rod, the core rod may be mounted to lathe, rotated by at least two rotors, and subjected to a heat source. Additionally, one of the at least two rotors may be phase-shifted from another one of the at least two rotors after the core rod is mounted on the lathe.
摘要:
Methods for modifying preform core ovality during and subsequent to the formation of an optical fiber preform. After MCVD deposition forms the core rod, but prior to overcladding of the core rod, the code rod may be etched to change its ovality. In order to etch the core rod, the core rod may be mounted to lathe, rotated by at least two rotors, and subjected to a heat source. Additionally, one of the at least two rotors may be phase-shifted from another one of the at least two rotors after the core rod is mounted on the lathe.
摘要:
Systems and methods are disclosed for an automatic and continuous supply of coating material to a coating applicator in optical fiber fabrication. The present invention switches from one coating reservoir to another by way of a transitional period in which both coating reservoirs are supplying coating material to the coating applicator. For example, while an in-use reservoir is supplying the coating material to the coating applicator, a standby reservoir is being filled, settled to off gas air bubbles and then slowly pressurized. A sized orifice is used to slowly bleed off pressure from the in-use reservoir at a rate that does not allow the pressure in the in-use reservoir from falling out of a desired pressure range. When the in-use reservoir is substantially emptied of coating material and the pressures in both reservoirs are substantially equalized, then both reservoirs simultaneously supply coating material to the coating applicator for a period of time before switching completely over to the standby reservoir.
摘要:
Disclosed is a dual-gap protector wherein both gaps will break down essentially simultaneously when a pulse of either polarity having a sufficient magnitude appears. An annular electrode is provided in the housing so as to form parallel gaps with respective end electrodes. The electrodes include a surface coating of a photoemissive and/or thermionic material so that light emission or heat resulting from the breakdown of one gap will influence the breakdown of the other gap.
摘要:
An expeditious method for introducing geometric perturbations into lightguide during fabrication offers a perturbation stream of amplitude and periodicity—constant or varying—to satisfy a variety of needs.
摘要:
Embodiments of the invention include a method and apparatus for making optical fiber preforms and optical fiber. The method includes the steps of positioning an overclad tube around a preform core rod, heating the overclad tube along the length thereof in the presence of a pressure gradient to collapse onto the preform core to form the overclad optical fiber preform, and adjusting the radial size of a heated portion of the preform core rod and/or the overclad tube to actively match the radial dimensions of the preform core rod along the length thereof with corresponding portions of the overclad tube. The active matching reduces variations in the physical dimensions of the preform core rod and/or the overclad tube, which improves transmission and other performance characteristics of fiber drawn from the created preform, e.g., by maintaining a relatively constant D/d ratio of the preform.