Our specialty optical fiber experience enables us to consistently produce some of the most sophisticated sensor fibers. Nufern test and measurement services bring confidence your final application will be successful.
Contact the Fiber Sensor Components Team for specifications and quotes.
Fiber Optic Gyroscope Coils
With a 25 year legacy of winding all types of precision optical fiber coils, the coil winding business unit offers a team of highly experienced scientists, engineers, and winders, together capable of winding the best in optical fiber coils. Cost effective and fast winding systems allow Nufern to provide a complete range of products.
Depending on requirements a great number of stock or custom coil structures can be supplied. Designs from potted, fully freestanding to totally constrained coils using pure or composite hub materials ensure environmental stability and ruggedness. Newest efforts at fiber miniaturization & hub mounting are yielding some of the worlds smallest high length precision wound coils.
Typical Quadrupole Patterns
Optical fiber gyroscope coils are commonly wound in a “quadrupole” pattern to reduce errors associated with thermal gradients and vibration. The “quadrupole” wind accomplishes this by making the co and counter rotating light beams (while guided in the fiber) follow as close to an identical but opposite spatial light path as possible. A “quadrupole” pattern is accomplished mechanically by beginning at the exact middle of a fiber length, half of the total fiber length necessary on each of two feed reels, and winding alternate layers from the two feed reels.
Coil winding is functionally divided into four operations:
- Wind the base layer on a smooth surface having no features. This determines the position of all subsequent fiber turns
- Wind the mid-layer portions of layers (after the base layer) in the larger portion of individual turns where fiber lies in a groove formed by two adjacent underlying turns
- Make crossovers once in each winding turn at the same radial position on each turn, so that the fiber crosses from one groove into the next groove in line across the surface of the coil
- Make transitions from completed layer to next higher layer
Each of these regions is unique in terms of the challenges presented to the coil winding process. The winding machines and proprietary winding methods assure successful completion of the overall winding in a consistent, repeatable manner.
(* Pair Transition)
Quadrupole Wound Coil Attributes
- Symmetrically wound coils for high degree of signal path reciprocity
- Quadrupole pattern for path equalization of thermal gradient effects
- Low winding tension for minimal coil stress
- Error-free, technician –controlled winding for superior density and gap avoidance
- Non-circular shapes possible
50 m → 6 km
Base Layer Turns
Up to 250
4 Layers → 100 Layers
Outer Diameter (D)
< 15 cm
Inner Diameter (d)
> 1.0 cm
< 5 cm
Fiber Optic Delay Lines
Fiber Optic Delay Lines are available from Nufern in the form of a free standing fiber optic coil or as a coil housed in a package with optical connectors for interfacing.
Fiber Optic Payout Spools
Optical Fiber Payout Spool is a precision wound optical fiber on a mandrel of specific geometrical shape. The major design criterion beyond length is “tear away” bend loss measured or calculated for deployment conditions. These spools are used to dispense fiber to tethered systems, often at high speeds. They are used primarily as a duplex optical fiber umbilical to transmit/receive data to/from the terminal point or obtain imagery from the terminal point. Since fiber is dispensed at high rates, payout dynamics plays a key role in the dispenser and spool design.
Nufern can fabricate Fiber Optic Payout Spools to customer specifications using our high strength fibers, optical fiber winding capabilities, and experience with wide ranging bonding agents which would hold the fiber together in the coil pack but at the same time would allow easy peel off of the fiber during deployment.
Fiber Optic Current Sensing Coils
Free standing coils (Helical Winding Pattern) are available in a range of sizes and fiber lengths.
With more than 25 years of experience in the coiling winding business, we’ve experienced some of the most challenging coils imaginable. As our technology moves forward, we believe the best is yet to come. We would be delighted to understand your next coil winding challenge. Please contact us to discuss the creation of a custom product.
Sensor Fibers encompass two major categories of specialty fiber. Fibers which when assembled and interrogated provide a sensing function (such as a gyroscope coil), and fibers which enable or connect components providing a sensing function (such as a catheter fiber for imaging). The two types can be entirely different. Depending on function these single mode, multimode, or combination fibers are required to exhibit specific measurable attributes for the task. The special attributes required are embodied in the core, cladding, and/or coatings, often all three. Our scientific and engineering expertise enables us to consistently produce some of the most sophisticated sensor fibers.View sensor fibers
As a company dedicated to specialty optical fiber and related products, Nufern is committed to providing testing services required by our clients in our own well equipped facility manned by our highly qualified scientific staff. Nufern can provide testing from the raw optical fiber level all the way to integrated sensors. Our facility is available and is regularly commissioned for external party services.
Fiber Level Testing
- Spectral measurements from 400 – 2100 nm
- All core/cladding/coating geometries for round and shaped fiber
- Dispersion and birefrengce
- Polarization crosstalk from visible to infrared
- Rare earth absorption
- Hydrogen permeability at high pressure up to 300° C
- All applicable Telcordia GR-20 testing capabilities
Coil Level Testing
- Thermal cycling to detect latent defects
- Optical loss using OTDR
- Polarization extinction ratio
- Insertion loss
- Wavelength dependent loss
- Coil coherence
- Coil thermal sensitivity
- Performance characterization over temperature range (-60° C to +150° C)
Gyroscope Level Testing
- Numerous static and dynamic tests available
- Allan variance plot for gyro bias and gyro angle random walk
- Scale factor
- Limited rotation rate capability