Engineering topics

Anthan, Donald J.

Publications and source records attributed to Anthan, Donald J..

7 records

NASA NTRS1991

Wavelength-multiplexed fiber-optic position encoder for aircraft control systems

NASA-Lewis has developed wavelength-multiplexed digital position fiber-optics transducers for use in aircraft control systems. A prototype LED-powered rotary encoder for a commercial aircraft turbofan engine is under construction which will have 8-bit resolution and an operational temperature in the 90 C range. A compact electrooptics module is also under development which will be able to withstand gas turbine environments. A second-generation device will incorporate integrated photonics technologies to increase optical power margin.

Beheim, Glenn↗

NASA NTRS1989

Modulated-splitting-ratio fiber-optic temperature sensor

A fiber-optic temperature sensor is described that uses a small silicon beamsplitter whose splitting ratio varies as a function of temperature. A four-beam technique is used to measure the sensor's temperature-indicating splitting ratio. This referencing method provides a measurement that is largely independent of the transmission properties of the sensor's optical fiber link. A significant advantage of this sensor, relative to other fiber-optic sensors, is its high stability, which permits the fiber-optic components to be readily substituted, thereby simplifying the sensor's installation and maintenance.

Beheim, Glenn↗

NASA NTRS1988

Loss-Compensated Optical Sensor Systems

Variations in fiber losses little effect on outputs. Fiber-optic sensing system conceptually related to electrical bridge circuit scarcely affected by variations in losses of optical fibers and connectors. Versions of system investigated for use as linear- and angular-position sensors for advanced aircraft controls. Position accuracies of 8 to 10 bits eventually achieved.

Beheim, Glenn↗

NASA NTRS1988

Modulated-splitting-ratio fiber-optic temperature sensor

A fiber-optic temperature sensor is described, which uses a small silicon beamsplitter whose splitting ratio varies as a function of temperature. A four-beam technique is used to measure the sensor's temperature-indicating splitting ratio. This referencing method provides a measurement that is largely independent of the transmission properties of the sensor's optical fiber link. A significant advantage of this sensor, relative to other fiber-optic sensors, is its high stability, which permits the fiber-optic components to be readily substituted, thereby simplifying the sensor's installation and maintenance.

Beheim, Glenn↗

NASA NTRS1988

Fiber-optic temperature sensor using a spectrum-modulating semiconductor etalon

Described is a fiber-optic temperature sensor that uses a spectrum modulating SiC etalon. The spectral output of this type of sensor may be analyzed to obtain a temperature measurement which is largely independent of the transmission properties of the sensor's fiber-optic link. A highly precise laboratory spectrometer is described in detail, and this instrument is used to study the properties of this type of sensor. Also described are a number of different spectrum analyzers that are more suitable for use in a practical thermometer.

Beheim, Glenn↗

NASA NTRS1987

Fiber-optic temperature sensor using a spectrum-modulating semiconductor etalon

Beheim, Glenn↗

NASA NTRS1987

Loss-compensation of intensity-modulating fiber-optic sensors

This report describes a new type of intensity-modulating fiber-optic sensor which as high immunity to the effects of variations in the losses of the fiber-link. A variable-splitting-ratio transducer is used to differentially modulate the intensities of the light which it transmits and reflects. Using a four-fiber optical link, light is impinged onto the transducer from either direction, and, in each case, the transmitted and reflected signals are measured. These four signals are then processed to remove the effects of the fiber and connector losses. Loss-compensated sensors of angular position and displacement are described, and their outputs are shown to be highly stable despite considerable variations in the transmissivities of the fiber-link components.

Beheim, Glenn↗