Design Challenges of a High Speed Tunable Laser Interrogator for Future Spacecraft Health Monitoring

Ibrahim, Selwan K.; O'Dowd, J.; Honniball, Arthur; Farnan, Martin

doi:10.1364/cleo_at.2015.atu1m.3

Cited by 9 publications

(10 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The vibration tests included resonance tests up to 2.5g, sinusoidal tests up to 22.5g, and random vibration tests up to 20g all over 3-axis within a 5-2000Hz frequency range, while the thermal tests covered an operating range from -20°C to +70°C. The environmental tests proved that the components may be used before, during and after a launcher take-off [6].…”

Section: Fig 4 Total Ionization Dose (Tid) Vs the Test Timementioning

confidence: 97%

“…The results show that all the spacings between neighboring Etalon peaks remain at 200pm throughout the test with a standard deviation (Std) of < 0.06pm. In addition to the radiation tests for the key critical components of the system (Tunable Laser and Etalon), they were also tested and validated for use in a launcher environment by subjecting them to extreme temperature and vibration tests as was reported in [6]. The vibration tests included resonance tests up to 2.5g, sinusoidal tests up to 22.5g, and random vibration tests up to 20g all over 3-axis within a 5-2000Hz frequency range, while the thermal tests covered an operating range from -20°C to +70°C.…”

Section: Fig 4 Total Ionization Dose (Tid) Vs the Test Timementioning

confidence: 99%

See 1 more Smart Citation

Design challenges of a tunable laser interrogator for geo-stationary communication satellites

Ibrahim¹,

Honniball²,

Todd³

et al. 2017

International Conference on Space Optics — ICSO 2016

Self Cite

View full text Add to dashboard Cite

Recently optical sensing solutions based on fiber Bragg grating (FBG) technology have been proposed for temperature monitoring in telecommunication satellite platforms with an operational life time beyond 15 years in geo-stationary orbit. Developing radiation hardened optical interrogators designed to be used with FBG sensors inscribed in radiation tolerant fibers offer the capabilities of multiplexing multiple sensors on the same fiber and reducing the overall weight by removing the copper wiring harnesses associated with electrical sensors. Here we propose the use of a tunable laser based optical interrogator that uses a semiconductor MG-Y type laser that has no moving parts and sweeps across the C-band wavelength range providing optical power to FBG sensors and optical wavelength references such as athermal Etalons and Gas Cells to guarantee stable operation of the interrogator over its targeted life time in radiation exposed environments. The MG-Y laser was calibrated so it remains in a stable operation mode which ensures that no mode hops occur due to aging of the laser, and/or thermal or radiation effects. The key optical components including tunable laser, references and FBGs were tested for radiation tolerances by emulating the conditions on a geo-stationary satellite including a Total Ionizing Dose (TID) radiation level of up to 100 krad for interrogator components and 25 Mrad for FBGs. Different tunable laser control, and signal processing algorithms have been designed and developed to fit within specific available radiation hardened FPGAs to guarantee operation of a single interrogator module providing at least 1 sample per second measurement capability across >20 sensors connected to two separate optical channels. In order to achieve the required temperature specifications of ±0.5°C across a temperature range of -20°C to +65°C using femtosecond inscribed FBGs (fs-FBG), a polarization switch is used to mitigate for the polarization dependent frequency shift (PDFS) induced from fs-FBG which could be in the order of > 20 pm causing > 2°C error in the measurement. Also special transducers were designed to isolate the strain from the FBGs to reduce any strain influence on the FBG temperature measurements while ensuring high thermal conductivity.In this paper we demonstrate the operation of an optical FBG interrogator as part of a hybrid sensor bus (HSB) engineering model system developed in the frame of an ESA-ARTES program and is planned to be deployed as a flight demonstrator on-board the German Heinrich Hertz geo-stationary satellite.

show abstract

Section: Fig 4 Total Ionization Dose (Tid) Vs the Test Timementioning

confidence: 97%

Section: Fig 4 Total Ionization Dose (Tid) Vs the Test Timementioning

confidence: 99%

Design challenges of a tunable laser interrogator for geo-stationary communication satellites

Ibrahim¹,

Honniball²,

Todd³

et al. 2017

International Conference on Space Optics — ICSO 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…The current Ariane 5 uses over 500 wired electrical sensors for functional and telemetry purposes which requires a lot of effort in installation and testing in addition to the extra weight generated by the electrical cable harnesses solutions [1][2][3][4][5]. Wireless solutions have been proposed, however techniques to deliver power to the sensors and electromagnetic interference (EMI) is still a challenge [2].…”

Section: Introductionmentioning

confidence: 99%

“…Wireless solutions have been proposed, however techniques to deliver power to the sensors and electromagnetic interference (EMI) is still a challenge [2]. Optical fibre sensing solutions overcome the requirement to deliver power and is immune to EMI [3][4][5]. Fig.…”

Section: Introductionmentioning

confidence: 99%

Demonstration of a high speed hybrid electrical and optical sensing system for next generation launcher applications

Ibrahim¹,

O'Dowd²,

Honniball³

et al. 2017

International Conference on Space Optics — ICSO 2016

Self Cite

View full text Add to dashboard Cite

The Future Launchers Preparatory Programme (FLPP) supported by the European Space Agency (ESA) has a goal of developing various launch vehicle system concepts and identifying the technologies required for the design of Europe's Next-Generation Launcher (NGL) while maintaining competitiveness on the commercial market. Avionics fiber optic sensing technology was investigated as part of the FLPP programme. Here we demonstrate and evaluate a high speed hybrid electrical/optical data acquisition system based on commercial off the shelf (COTS) technology capable of acquiring data from traditional electrical sensors and optical Fibre Bragg Grating (FBG) sensors. The proposed system consists of the KAM-500 data acquisition system developed by Curtis-Wright and the I4 tunable laser based fiber optic sensor interrogator developed by FAZ Technology. The key objective was to demonstrate the capability of the hybrid system to acquire data from traditional electrical sensors used in launcher applications e.g. strain, temperature and pressure in combination with optical FBG sensors, as well as data delivery to spacecraft avionics systems. The KAM-500 was configured as the main acquisition unit (MAU) and provided a 1 kHz sampling clock to the I4 interrogator that was configured as the secondary acquisition unit (SAU) to synchronize the data acquisition sample rate between both systems. The SAU acquired data from an array of optical FBG sensors, while the MAU data acquisition system acquired data from the electrical sensors. Data acquired from the optical sensors was processed by the FAZ I4 interrogation system and then encapsulated into UDP/IP packets and transferred to the KAM-500. The KAM-500 encapsulated the optical sensor data together with the data acquired from electrical sensors and transmitted the data over MIL-STD-1553 and Ethernet data interface. The temperature measurements resulted in the optical and electrical sensors performing on a par with each other, with all sensors recording an accuracy within 0.35% FS over the full temperature range of -70ºC to +180ºC. The pressure measurements were performed over a 0 to 5 bar absolute pressure range and over different temperatures across a -40ºC to +80ºC range. The tests concluded that the optical pressure sensors performed on par with the electrical pressure sensor for each temperature set, where both sensor technologies measured a pressure accuracy of 1.2% FS. As for the strain measurements, the results show the optical and electrical sensors can measure to within 1% FS (Full Scale) of measurement range ±1,200 µstrain. The proposed hybrid system can be potentially used for next generation launcher applications delivering weight reduction, improvement in measurement coverage and reduction in Assembly, Integration and Testing (AIT) over traditional electrical systems.

show abstract

“…FBGs interrogated with polarized frequency swept sources (e.g. polarized tunable lasers) could suffer from polarization dependent frequency shift (PDFS) [5][6] which could be typically sub pm and up to 40pm. PDFS in FBG sensors is due to inherent birefringence in the FBG due to the fiber or due to transversal strain applied on the FBG during mounting/packaging of the sensor.…”

Section: Introductionmentioning

confidence: 99%

Interrogation and mitigation of polarization effects for standard and birefringent FBGs

Ibrahim¹,

Roosbroeck

O'Dowd³

et al. 2016

SPIE Proceedings

Self Cite

View full text Add to dashboard Cite

Optical sensors based on Fiber Bragg Gratings (FBGs) are used in several applications and industries. Several inscription techniques and types of fibers can be used. However, depending on the writing process, type of fiber used and the packaging of the sensor a Polarization Dependent Frequency Shift (PDFS) can often be observed with polarized tunable laser based optical interrogators. Here we study the PDFS of the FBG peak for the different FBG types. A PDFS of <1pm up to >30pm was observed across the FBGs. To mitigate and reduce this effect we propose a polarization mitigation technique which relies on a synchronous polarization switch to reduce the effect typically by a factor greater than 4. In other scenarios the sensor itself is designed to be birefringent (Bi-FBG) to allow pressure and/or simultaneous temperature and strain measurements. Using the same polarization switch we demonstrate how we can interrogate the Bi-FBGs with high accuracy to enable high performance of such sensors to be achievable.

show abstract

Design Challenges of a High Speed Tunable Laser Interrogator for Future Spacecraft Health Monitoring

Cited by 9 publications

References 1 publication

Design challenges of a tunable laser interrogator for geo-stationary communication satellites

Design challenges of a tunable laser interrogator for geo-stationary communication satellites

Demonstration of a high speed hybrid electrical and optical sensing system for next generation launcher applications

Interrogation and mitigation of polarization effects for standard and birefringent FBGs

Contact Info

Product

Resources

About