Scanning Mach-Zehnder Interferometer Research Articles

Measurement method of high spectral resolution lidar with a multimode laser and a scanning Mach-Zehnder interferometer.

A simple high spectral resolution lidar technique using a multi-longitudinal mode laser is proposed for measuring aerosol extinction and backscattering coefficients. A scanning interferometer having the same free spectral range as the mode spacing of the laser is used to separate Rayleigh from Mie scattering. Scanning the interferometer in the span of one fringe, the lidar signals at the minimum and maximum Mie-scattering transmission are measured. The Rayleigh scattering signal is analyzed from these signals, and the aerosol extinction coefficient is derived. The interferometer transmittance for Mie scattering is calibrated with the reference signals taken with a portion of the transmitted laser beam.

Transformation of Vibration Shapes in Resonances of Micromachined Piezoelectric Circular Membrane

In this paper, we report observation and study of transformation of the vibration shapes in resonances of micromachined piezoelectric circular membrane. Micromachined piezoelectric zinc oxide circular membrane was fabricated and the vibration shapes of the membrane at different frequencies were measured by a scanning Mach-Zehnder interferometer. The finite element analysis with a commercial software ANSYS was performed to study the vibration characteristics of the circular membrane. The result shows that the transformation of the vibration shapes in resonances of the circular membrane could be influenced by its asymmetrical characteristics.

Piezoelectric biosensor platform based on ZnO micro membrane

In this paper, the piezoelectric ZnO micro membranes were fabricated and investigated as biosensor platform. This membrane device was fabricated by MEMS technology from ZnO thin film deposited by megnetron sputtering. The vibration behaviors of membranes in different sizes were analyzed using scanning Mach–Zehnder interferometer. The resonance frequencies and vibration modes were got and the mass sensitivities were calculated. The results show that the ZnO device works like membrane and could be considered as a good candidate of biosensor platform. The stress of the membrane structure was calculated and the results indicate a potential application that membrane could also be used to monitor the stress during the thin film deposition.

Frequency Dependent Electro-Optic Properties of Potassium Lithium Tantalate Niobate Single Crystal

Single crystals K0.95Li0.05Ta1-x Nb x O3 (KLTN) - x = 0.6 are grown and the transmission spectra show the UV absorption edge is about 400 nm for the transparent KLTN crystal sample. The refractive index and the frequency dependent of linear electro-optic coefficients of KLTN single crystals in the tetragonal phase are characterized at room temperature. The minimum deviation method is used for the refractive index measurements and the electro-optic properties have been investigated using the senarmont method and the auto scanning mach-zehnder interferometer technique. The EO measurements were taken with the continuous low frequency of applied ac field from 100 Hz to 100 KHz. Large electro-optic responses are observed and the coefficients, γ33 = 216.7 pm/V, γ13 = −21.2 pm/V, and γc = 242.9 pm/V at 1 kHz are measured for the crystals. The E-O properties show that the high quality KLTN single crystals have the potential in the field of optical modulation and deflection field devices.

Measurement of longitudinal piezoelectric coefficient of lead zirconate titanate thin/thick films using a novel scanning Mach-Zehnder interferometer

Developing a well accepted method for piezoelectric characterization of piezoelectric thin/thick films is an essential issue in the research of piezoelectric micro-electromechanical systems. This article presents a scanning interferometric technique for piezoelectric characterization of lead zirconate titanate (PZT) thin/thick film on silicon substrate. This technique is established using a newly developed scanning Mach-Zehnder interferometer with ultra-high resolution. The apparent longitudinal piezoelectric coefficients of both sol–gel derived PZT thin films and hybrid PZT thick films are measured using the scanning technique. The roles of several film processing factors on the piezoelectric properties of the resultant films are also discussed.

Linear Electro-optic Effect of 0.88Pb(Zn1/3Nb2/3)O3–0.12PbTiO3 Single Crystal

The linear electro-optic (E-O) coefficients of poled 0.88Pb(Zn1/3Nb2/3)O3–0.12PbTiO3 single crystal were characterized using an automated scanning Mach-Zehnder interferometer and the senarmont compensator method at room temperature. They were obtained at a wavelength of 632.8 nm: r33=134 pm/V, r13=7 pm/V, r51=462 pm/V, and rc=131 pm/V respectively and the refractive indices: ne=2.57 and no=2.46. The large r51 coefficient compared with r33 is caused by the high dielectric constant at perpendicular to the polar-axis compared with the dielectric constant along the c-axis. Comparison with the quadratic E-O coefficients measured at near and above the Curie temperature suggests that the values of the quadratic E-O coefficients measured earlier may be smaller than the intrinsic ones due to the influence of micro-polar regions. The development of an automated scanning Mach-Zehnder interferometer, which is less susceptible to the errors caused by the laser intensity fluctuation and drafting in the optical path length in the system, is also described.