Applications

Characterizing Passive Optical Components and Assemblies:
Luna's Optical Vector Analyzer™ (OVA) enables complete characterization of passive optical components with industry-leading accuracy and speed. The OVA measures the linear transfer function of an optical component or assembly with a single scan of a tunable laser. From this single measurement the OVA characterizes the IL, GD, CD, PMD, Phase Ripple and more. In addition, the OVA offers a unique Time Domain view of the device under test, enabling troubleshooting of the device as well as time-domain filtering of the data for more accurate measurements.

Characterizing Optical Properties of Planar Waveguides:
Planar optical waveguide technologies are the key elements in the modern, high speed optical network. Recent, broad deployment of optical and hybrid optoelectronic chips and planar light circuits (PLCs) has been driven by the cost, size and operational benefits that these architectures offer. Luna Optical Vector Analyzers offer distinct measurement advantages that make characterizing the optical properties of planar waveguides, optical chips and planar light circuits easy.

Finding Fiber Faults in High Speed Optical Networks:
Testing of fiber optic components, accessories and networks is becoming critical in today's demanding applications. Luna's Optical Backscatter Reflectometer™ (OBR) is a fiber optic diagnostic tool that locates and troubleshoots splices, breaks, connectors and more in fiber assemblies with industry-leading spatial resolution, sensitivity and accuracy. The OBR can also transform standard telecom-grade fiber into a distributed strain and temperature sensor with an additional software option.

Avionics:
Luna's Optical Frequency Domain Reflectometry technique is a practical tool for diagnosing and troubleshooting the types of fiber networks found in aviation electronics applications. Short length optical communications networks, like those in avionics and aerospace applications, require frequent health assessment. Precise recognition and localization of faults, accurate measurement of loss through the link are critical to maintaining signal integrity. The unique attributes of Luna's technology include zero dead-zone, the ability to unambiguously identify different types of failure modes encountered in short-haul single- and multimode fiber networks, and the capability to perform distributed sensing with unaltered single- or multimode telecommunication grade optical fiber. With Luna's technology one can detect and localize bends, breaks, bad splices and poor connections with up to 10 micron spatial resolution with zero dead-zone. Links can be measured with 1 mm resolution over up to 2000 m of fiber length. In addition to fault location and loss measurement, distributed temperature and strain measurements along standard optical fiber can occur, which saves time and money.

Aircraft Health Monitoring:
The primary aging mechanisms that are known to reduce the economic service life of both civilian and military aircraft are corrosion, stress corrosion cracking and fatigue. In the past, foil strain gauges have worked well for this evaluation but they require multiple lead wires per gauge, which consumes time in installation and provides for undesirable masses of cables. Foil gauges are also prone to drift and tend to have problems with electromagnetic interference. When compared to conventional foil gauges, Luna's fiber optic sensors offer substantially reduced size and weight, greatly simplified installation and immunity to electromagnetic interference. Not only are substantial cost savings realized due to labor and material reduction in the installation process, increased coverage via distributed sensing means higher spatial resolution and an increased probability of early damage detection.

Aircraft manufacturers are continuing to incorporate more carbon fiber reinforced materials into their new aircraft structures. These composite structures weigh less than metal structures and they are stronger. However, composites can still deteriorate, often in the form of fractures, cracks or delaminations. Due to the construction of the composites, these faults are often invisible to the naked eye. Luna's Rayleigh Backscatter technology is excellent for structural health monitoring of composite structures. Luna's easy-to-use Optical Backscatter Reflectometer™ (OBR) 4400 instrument can quickly detect and locate problems over 70 meters of length.

Wind Turbine Health Monitoring:
Luna's sensors are robust, tolerate in harsh environments, immune to lighting strikes, highly multiplexable, inexpensive, fast, embeddable and lightweight. With a Luna Distributed Sensing System™, thousands of sensors can be multiplexed providing strain and temperature information with high spatial resolution which provides early detection of cracks, disjoints and dislocations on a wind turbine blade. This would in turn reduce labor costs for turbine inspection; eliminate the need for unnecessary replacement based on time of use; and reduce the chances of catastrophic failure.

Power Generator Health Monitoring:
As electrical generators age, they become increasingly prone to failure. The failure of a single generator can greatly reduce the output of a power plant while the unit is down for evaluation and repair. Failure from overheating can result from operating the machines beyond their specifications or by problems such as ventilation blockage due to excessively dirty environments. To extend operational life, power plants often intentionally run their electrical generators at less than optimal efficiencies during non-peak usage times. Applying Luna's distributed sensing technology allows numerous sensors to be multiplexed along the length of a single optical fiber allowing for inexpensive, detailed real-time temperature monitoring of the generator.

Cavity Detection / Sinkhole Monitoring:
Embedded cavities, or sink holes that may induce soil collapse present a major risk to the French railway system. Current technologies such as ground penetrating radar, seismic analysis or infrared thermography are increasing in use to locate cavities, but do not offer continuous embedded cavity monitoring, a major concern for rail companies. Luna's Optical Backscatter Reflectometer™ (OBR) 4400 device with distributed Rayleigh sensing, was used in an experiment in France for the possible use as a cavity detection or sink hole warning system on railway track beds and tunnels. The experiment conducted a full-scale laboratory investigation of Luna's OBR, which uses Optical Frequency Domain Reflectometry, together with a competing technology that uses Brillouin scattering. For more information, read the release "Luna's Fiber Optic Sensing Used in Railway Test in France."

Security:
A communications infrastructure secure from threats of intrusion and espionage is a key element in the overall outlook of network security. Monitoring a fiber optic network presents a particularly difficult monitoring challenge due to the fact that fiber tapping methods can be made to be nearly undetectable. Methods of intrusion detection that involve either monitoring or conditioning the data stream work to protect a link in the presence of an intrusion event but do not provide information about the location or nature of the intrusion. Luna researchers found that using fiber fingerprints, you can monitor the network in situ for the types of changes associated with modern, hard-to-detect optical taps. This technique is not only capable of real-time monitoring of whether or not a fiber network has been breached by a difficult-to-detect source, it is also capable of determining the location and nature of the breach point in the network. For more details, see Luna publication "Luna Researchers Harness the Power of Fiber Fingerprints."