Name: FC Series Fiber Gyro Coils for Fiber Optic Gyroscopes
Brand: Luna
SKU: FC Series

Overview

The FC series are fiber gyro coils for high-performance Sagnac fiber optic gyroscopes. They are built using specialized potting adhesive, winding techniques and process controls. The coils can be wound with many types of single-mode (SM) and polarization-maintaining (PM) fiber, in a range of lengths and diameters.

Standard coils are frameless and held together with proprietary potting adhesives. Framed construction is also available. The coils can be wound in quadrupole, octupole or other patterns. These patterns minimize the Shupe effect, which degrades gyro performance when the temperature changes.

Shupe effect mitigation and mounting

Additional Shupe effect mitigation is offered at three levels to further improve temperature and vibration performance. A mounting service is available on request to preserve coil performance in demanding applications.

Test data

Coils can be supplied with full test data. For PM fiber coils this includes polarization crosstalk versus distance along the fiber at specified temperatures. For SM fiber coils it includes PDL versus temperature and PMD versus temperature. PER and insertion loss data are also provided.

Key Features

Low polarization crosstalk (PM)
Low PDL and PMD (SM)
Thermally and vibrationally stable
Different winding patterns available
Advanced process controls
Low temperature sensitivity
Low vibration sensitivity
Highly symmetric
Available frameless or framed
Complete test data available, including polarization crosstalk vs. distance

Specifications

Optical

Operating wavelength	840, 1060, 1310, or 1550 nm Specify if others
Winding induced IL	< 0.2 dB/km

Polarization

PER PM	> 24 dB over full temperature range Typical values
PER temperature variation (−40 to +80°C) PM	±2 dB Typical values
Max. polarization crosstalk PM	< −50 dB at 25°C; < −45 dB over full temperature range Typical values
Number of polarization crosstalk peaks above −55 dB PM	<15 at 25°C; <30 over full temperature range Typical values
Average polarization crosstalk PM	< −68 dB at 25°C; < −55 dB over full temperature range Typical values

Shupe Effect

Max. bias error, no Shupe mitigation	< 2 degrees/hour typical peak-to-peak
Max. bias error, Level I Shupe mitigation A	< 1 degree/hour typical peak-to-peak
Max. bias error, Level II Shupe mitigation B	< 0.5 degrees/hour typical peak-to-peak
Max. bias error, Level III Shupe mitigation C	< 0.25 degrees/hour typical peak-to-peak

Mechanical

Fiber length	10 m to 5 km Typical values. Web page overview states lengths of 50 meters to 5 kilometers
Coil ID	15 mm to 120 mm
Winding patterns	Quadrupole (Standard); Octupole or others (Special)
Fiber type	SM, PM

Specifications are taken from the manufacturer's documentation. See the datasheet for complete and current values.

Options & Accessories

Option	Description
A	Level 1 Shupe mitigation — Shupe mitigation procedures based on an average optimization treatment.
B	Level 2 Shupe mitigation — Additional Shupe mitigation treatment, including more involved optimization procedures on each coil.
C	Level 3 Shupe mitigation — Shupe mitigation based on individual optimization procedures for each coil. Details of Shupe errors versus time with step temperature changes are supplied. A minimum of 3 trial coils should be ordered before production quantities.
Q	Quadrupole winding
O	Octupole winding
S	Simple winding