Laser diode interferometer for vibration and sound pressure measurements

Takahashi, Hideo; Masuda, Chihiro; Gotoh, Yasuo; Koyama, J.

doi:10.1109/19.192353

Cited by 10 publications

(6 citation statements)

References 3 publications

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“…The details of the heterodyne interference technique have been reported. 16,17 The measurement principle for refractive index and film thickness is the same as that for ellipsometry. The incident angle of the laser beam to the film surface was 70Њ.…”

Section: Methodsmentioning

confidence: 99%

Optical Properties of Fluorinated Silicon Oxide and Organic Spin-on-Glass Films for Thin-Film Optical Waveguides

Homma

Ariyama

Kondo

et al. 2000

J. Electrochem. Soc.

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Optical properties of fluorinated silicon oxide (SiOF) and organic spin-on-glass (SOG) films in optical waveguide structures are investigated. The SiOF film for a core layer in an optical waveguide was formed at 23ЊC by a liquid-phase deposition (LPD) technique using a supersaturated hydrofluosilicic acid (H 2 SiF 6 ) aqueous solution. The deposition rate using aluminum (Al) for supersaturation in LPD was around 42-50 nm/h. A siloxane-based SOG film was also evaluated for a cladding layer. Although the weak absorption peaks for fundamental vibration of the Si-OH bond in the Fourier transform infrared spectra are observed for thick LPD-SiOF films, the absorption bands for the H-OH bond are under the detection limit. The absorption peaks of Si-OH and H-OH bonds for the organic SOG films were negligibly small. The deviation ranges of refractive indices with thickness difference for the LPD-SiOF and organic SOG films were lower than 0.005 (<0.35%) and 0.01 (<0.71%), respectively, in the wavelengths ranging from 400 to 860 nm. The dispersion of the refractive index measured by spectroellipsometry agreed well with fitting results for both films in the measurement wavelengths ranging from 400 to 860 nm. In the measurement wavelength region, the organic SOG film kept lower refractive indices than the LPD-SiOF film. Any absorption due to water was not observed for the transmittance spectra in the wavelengths ranging from 350 to 2500 nm.

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Section: Methodsmentioning

confidence: 99%

Optical Properties of Fluorinated Silicon Oxide and Organic Spin-on-Glass Films for Thin-Film Optical Waveguides

Homma

Ariyama

Kondo

et al. 2000

J. Electrochem. Soc.

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“…LDV reflects a laser light beam off of the object under test, and measures the backscattered light for a Doppler frequency or phase change with respect to a reference light beam usually through a Michelson interferometer [17, p. 24], [28], [29]. The use of a laser beam allows for a very small target point of measurement on the vibrating object without the addition of any mass or load.…”

Section: ) Contact and Proximity Transducersmentioning

confidence: 99%

Feasibility Study on a Noncontact Remote-Sensing Vibration Transducer Using RF Polarimetry

Mueller

Pratt

2013

IEEE Trans. Instrum. Meas.

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This paper presents a novel, noncontact vibration transducer system using radio frequency (RF) polarimetry, which allows for vibration measurements to be collected remotely and nonintrusively at a distance. Movement or vibration of an object within the RF propagation channel can alter the combined direct, reflected, and multipath RF signals, thereby changing the received signal's polarization. This paper presents the theory to analyze a RF signal's polarization for used as a vibration transducer. The proposed transducer leverages the entire bandwidth of the RF signal using the frequencydependent polarization mode dispersion phenomenon that occurs in multipath channels. To analyze the approach, a software model has been constructed and used to simulate and characterize the transducer's performance. A feasibility comparison of this RF polarimetry technique to similar vibration transducers, including laser Doppler vibrometry, shows this new transducer to be easier and less expensive to implement without significant tradeoffs in performance. Finally, laboratory experiments verify the software model and demonstrate a real-world prototype implementation. The pure-tone vibration of tuning forks, the forced and free vibrations of a ringing telephone, and the rotational motion of a desktop fan have been measured and are presented as an evidence of this RF polarimetry transducer's diverse capabilities in vibrometry.

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“…It is a spectral imager based on an acousto-optical tunable filter (AOTF) which is efficient at detecting the distribution of NO2 with a high spatial and temporal resolution. Applying an AOTF in a spectrometer is a technique already used before [3], but also other applications are feasible [4].…”

Section: Introductionmentioning

confidence: 99%

Practical Driving Electronics for an AOTF-Based NO₂ Camera

Vanhamel

Berkenbosch

Dekemper

et al. 2019

IEEE Trans. Instrum. Meas.

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The measurement of NO2 abundance in the air is of interest for monitoring pollution sources and air quality. A new instrumental concept has been recently introduced, which makes use of an acousto-optical tunable filter (AOTF) as the main component of a spectral imager. With the capability of resolving the absorption spectrum of NO2, and a high spatial and temporal sampling, this instrument can be seen as a NO2 camera. In this instrument, the selection of different optical wavelengths by the AOTF is done by applying an RF signal to the AOTF. The selected frequency and the applied amplitude are key parameters for the quality of the measurements. The design and assembly of an RF chain, consisting of an RF generator and RF amplifier, will lead to an electronics bench capable of driving the NO2 camera. In view of a potential spaceborne application of this instrumental concept, the design of the RF generator is only making use of spacequalified components. The current study focuses on the development of this part of the electronics bench.

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Laser diode interferometer for vibration and sound pressure measurements

Cited by 10 publications

References 3 publications

Optical Properties of Fluorinated Silicon Oxide and Organic Spin-on-Glass Films for Thin-Film Optical Waveguides

Optical Properties of Fluorinated Silicon Oxide and Organic Spin-on-Glass Films for Thin-Film Optical Waveguides

Feasibility Study on a Noncontact Remote-Sensing Vibration Transducer Using RF Polarimetry

Practical Driving Electronics for an AOTF-Based NO₂ Camera

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Laser diode interferometer for vibration and sound pressure measurements

Cited by 10 publications

References 3 publications

Optical Properties of Fluorinated Silicon Oxide and Organic Spin-on-Glass Films for Thin-Film Optical Waveguides

Optical Properties of Fluorinated Silicon Oxide and Organic Spin-on-Glass Films for Thin-Film Optical Waveguides

Feasibility Study on a Noncontact Remote-Sensing Vibration Transducer Using RF Polarimetry

Practical Driving Electronics for an AOTF-Based NO2 Camera

Contact Info

Product

Resources

About

Practical Driving Electronics for an AOTF-Based NO₂ Camera