Acoustic Sensitivity of Interferometric Fiber-Optic Mandrel Hydrophone using Orthogonal Design

Theoretical calculations and experimental study of the acoustic sensitivity suppression level of optical fiber inside the cables of a special design in the frequency range 20-20000 Hz were carried out. A high degree of reduction in acoustic sensitivity has been achieved. It was more than 29 dB suppression relatively to the standard single-mode SMF - 28 fiber in a polymer shell. This result can significantly increase the sensitivity of measuring systems based on fiber-optic interferometers.

Download Full-text

Side-Polished Fiber-Optic Line Sensor for High-Frequency Broadband Ultrasound Detection

Sensors ◽

10.3390/s19020398 ◽

2019 ◽

Vol 19 (2) ◽

pp. 398

Author(s):

Jeongmin Heo ◽

Kyu-Tae Lee ◽

Ryun Kim ◽

Hyoung Baac

Keyword(s):

Fiber Optic ◽

Signal To Noise Ratio ◽

High Sensitivity ◽

Field Interaction ◽

Acoustic Frequency ◽

Detection Range ◽

Optical Detectors ◽

Ultrasound Sensor ◽

Acoustic Sensitivity ◽

Side Polished Fiber

We demonstrate a side-polished fiber-optic ultrasound sensor (SPFS) with a broad frequency bandwidth (dc–46 MHz at 6-dB reduction) and a wide amplitude detection range from several kPa to 4.8 MPa. It also exhibits a high acoustic sensitivity of 426 mV/MPa with a signal-to-noise ratio of 35 dB and a noise-equivalent pressure of 6.6 kPa (over 1–50 MHz bandwidth) measured at 7-MHz frequency. The SPFS does not require multi-layer-coated structures that are used in other high-sensitivity optical detectors. Without any coating, this uses a microscale-roughened structure for evanescent-field interaction with an external medium acoustically modulated. Such unique structure allows significantly high sensitivity despite having a small detection area of only 0.016 mm2 as a narrow line sensor with a width of 8 μm. The SPFS performance is characterized in terms of acoustic frequency, amplitude responses, and sensitivities that are compared with those of a 1-mm diameter piezoelectric hydrophone used as a reference.

Download Full-text

Theoretical Analysis of Acoustic Sensitivity of Fiber Optic Hydrophone with Multilayer Fiber Coils

Sensor Letters ◽

10.1166/sl.2012.2482 ◽

2012 ◽

Vol 10 (7) ◽

pp. 1448-1451 ◽

Cited By ~ 2

Author(s):

Wentao Zhang ◽

Fang Li ◽

Yuliang Liu

Keyword(s):

Theoretical Analysis ◽

Fiber Optic ◽

Acoustic Sensitivity

Download Full-text

Pseudo working-point control measurement scheme for acoustic sensitivity of interferometric fiber-optic hydrophones

Chinese Optics Letters ◽

10.3788/col20080605.0381 ◽

2008 ◽

Vol 6 (5) ◽

pp. 381-383 ◽

Cited By ~ 1

Author(s):

王泽锋王泽锋 ◽

Zefeng Wang Zefeng Wang ◽

胡永明胡永明 ◽

Yongming Hu Yongming Hu ◽

孟洲孟洲 ◽

...

Keyword(s):

Fiber Optic ◽

Control Measurement ◽

Measurement Scheme ◽

Point Control ◽

Acoustic Sensitivity ◽

Working Point

Download Full-text

Imaging and diffraction modes in Scanning Transmission Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144814 ◽

1986 ◽

Vol 44 ◽

pp. 684-687

Author(s):

J. M. Cowley ◽

R. Glaisher ◽

J. A. Lin ◽

H.-J. Ou

Keyword(s):

Scanning Transmission Electron Microscopy ◽

High Efficiency ◽

Fiber Optic ◽

Image Intensifier ◽

Detector System ◽

Detector Plane ◽

Secondary Electrons ◽

Transmission Electron ◽

Scanning Transmission ◽

Special Detector

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.

Download Full-text

Synthesis, performance and growth mechanism of silver nanoparticle coated SERS fiber probe

Matériaux & Techniques ◽

10.1051/mattech/2018061 ◽

2019 ◽

Vol 107 (3) ◽

pp. 305

Author(s):

Mengmei Geng ◽

Yuting Long ◽

Tongqing Liu ◽

Zijuan Du ◽

Hong Li ◽

...

Keyword(s):

Silver Nanoparticles ◽

Absorption Spectrum ◽

Reaction Time ◽

Growth Mechanism ◽

Fiber Optic ◽

Fiber Optic Probe ◽

Visible Absorption ◽

Fiber Probe ◽

Surface Enhanced Raman ◽

Optic Probe

Surface-enhanced Raman Scattering (SERS) fiber probe provides abundant interaction area between light and materials, permits detection within limited space and is especially useful for remote or in situ detection. A silver decorated SERS fiber optic probe was prepared by hydrothermal method. This method manages to accomplish the growth of silver nanoparticles and its adherence on fiber optic tip within one step, simplifying the synthetic procedure. The effects of reaction time on phase composition, surface plasmon resonance property and morphology were investigated by X-ray diffraction analysis (XRD), ultraviolet-visible absorption spectrum (UV-VIS absorption spectrum) and scanning electron microscope (SEM). The results showed that when reaction time is prolonged from 4–8 hours at 180 °C, crystals size and size distribution of silver nanoparticles increase. Furthermore, the morphology, crystal size and distribution density of silver nanoparticles evolve along with reaction time. A growth mechanism based on two factors, equilibrium between nucleation and growth, and the existence of PVP, is hypothesized. The SERS fiber probe can detect rhodamin 6G (R6G) at the concentration of 10−6 M. This SERS fiber probe exhibits promising potential in organic dye and pesticide residue detection.

Download Full-text