The algorithm treatment optimization of the double beam laser vibrometer signal for large vibration amplitude

A new device and methodology for vertically coupling confocal Raman microscopy with optical tweezers for the in situ physico- and photochemical studies of individual microdroplets (Ø ≤ 10 µm) levitated in air is presented. The coupling expands the spectrum of studies performed with individual particles using laser tweezers Raman spectroscopy (LTRS) to photochemical processes and spatially resolved Raman microspectroscopy on airborne aerosols. This is the first study to demonstrate photochemical studies and Raman mapping on optically levitated droplets. By using this configuration, photochemical reactions in aerosols of atmospheric interest can be studied on a laboratory scale under realistic conditions of gas-phase composition and relative humidity. Likewise, the distribution of photoproducts within the drop can also be observed with this setup. The applicability of the coupling system was tested by studying the photochemical behavior of microdroplets (5 µm < Ø < 8 µm) containing an aqueous solution of sodium nitrate levitated in air and exposed to narrowed UV radiation (254 ± 25 nm). Photolysis of the levitated NaNO3 microdroplets presented photochemical kinetic differences in comparison with larger NaNO3 droplets (40 µm < Ø < 80 µm), previously photolyzed using acoustic traps, and heterogeneity in the distribution of the photoproducts within the drop.

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Development of Lead-Free Piezoelectric Thick Films with a/b-Axis-Oriented Bi4-xPrxTi3O12

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.301.61 ◽

2006 ◽

Vol 301 ◽

pp. 61-64 ◽

Cited By ~ 2

Author(s):

Hirofumi Matsuda ◽

Takashi Iijima

Keyword(s):

Piezoelectric Coefficient ◽

Thick Films ◽

Lead Free ◽

Piezoelectric Film ◽

Chemical Solution ◽

Solution Deposition ◽

Beam Laser ◽

Chemical Solution Deposition Method ◽

Double Beam ◽

Laser Displacement Meter

Pr-substituted Bi4Ti3O12 (BPT, Bi4-xPrxTi3O12, x=0.1-0.4) polycrystalline thick films with a-/b-axes orientations and thickness of 2-3 μm were grown on sputter-grown IrO2 layers by chemical solution deposition method for developing lead-free piezoelectric film microdevices. Electric-field-induced strains measurements were performed by double-beam laser displacement meter and longitudinal strain of e=0.25 % under 400 kV/cm and piezoelectric coefficient d33=63 pm/V at 10 Hz were observed in BPT thick film of x=0.1 with a-/b-axes mixed orientations. The value of strain closely related to spontaneous polarization and monotonously decreased with increasing x. Microstructures of 3 μm-thick BPT films were fabricated by photolithography and dry etching processes with several tens micrometers in size.

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Thickness-Dependent Electrical Properties in Lanthanum-Doped Pzt Thick Films

MRS Proceedings ◽

10.1557/proc-433-325 ◽

1996 ◽

Vol 433 ◽

Cited By ~ 9

Author(s):

H.D. Chen ◽

K.K. Li ◽

C.J. Gaskey ◽

L.E. Cross

Keyword(s):

Lead Zirconate Titanate ◽

Thick Films ◽

Sol Gel ◽

Lead Zirconate ◽

Silicon Substrates ◽

Residual Tensile Stress ◽

Beam Laser ◽

Lanthanum Content ◽

Double Beam ◽

Gel Technique

AbstractLanthanum-doped lead zirconate titanate (PLZT) films, with thickness up to 10 μm, are fabricated on platinized silicon substrates through a modified sol-gel technique. Thicknessdependent piezoelectric properties measured with a double-beam laser interferometer show piezoelectric relaxation in field-induced strain as the ac driving field exceeds 10 kV/cm. In addition, the strain levels of PLZT thick films are approximately one third of those of undoped PZT films under the same fabrication and measurement conditions. For 1 μm PZT(55/45) films doped with 0, 2, and 4 mole% La, the P-E hysteresis exhibits decreasing squareness with increasing lanthanum content while the piezoelectric d33 coefficient reduces from 130 to 52 pC/N. Residual (tensile) stress in these films and resulted depoling effect may be responsible for this phenomenon.

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Laser-Based Instrument for Electric Dichroism Spectroscopy of Small Molecules

Applied Spectroscopy ◽

10.1366/0003702864508971 ◽

1986 ◽

Vol 40 (4) ◽

pp. 483-486 ◽

Cited By ~ 2

Author(s):

K. L. Jansen ◽

J. M. Harris

Keyword(s):

Small Molecules ◽

High Voltage ◽

Electronic Structures ◽

Dielectric Strength ◽

Voltage Source ◽

Chemical Information ◽

Beam Laser ◽

Double Beam ◽

Electric Dichroism ◽

High Voltage Source

While the chemical information provided by electric dichroism spectroscopy can be useful for studying the conformation and electronic structures of molecules in solution, the dichroism signals produced at fields approaching the dielectric strength of organic solvents are extremely small and difficult to detect. A double-beam, laser-based instrument for electric dichroism measurements is described which allows detection of dichroism signals corresponding to changes in absorbance of less than 10−6 with only a 1.2-kV high-voltage source.

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