A kind of photo-electronic integrated acceleration seismic detecting technology, which is novel and precise based on
waveguide M-Z interference, is presented. It provieds modern geologic prospect with a novel detection technology. The
principle of the photo-electronic integrated acceleration seismic geophone is introduced in this paper. The core of the
photo-electronic integrated acceleration is the silicon harmonic oscillator, which is supported by four silicon beams and
integrated on the signal beam of the M-Z interferometer. When the seismic mass is subjected to a normal acceleration
az, the acceleration az, will result in an inertial force Fz, causing the mass to move up or down like the piston, until the
counter force of the beam suspension equals this inertial force. The principle of the harmonic oscillator is briefly
introduced, the factors influencing the anisotropic etching quality of the harmonic oscillator are analyzed in detail. In
experiment, the fabrication technology was studied and improved. The high quality harmonic oscillator has been
successfully fabricated. It has been applied in the integrated optical chip of "the theory and experiment research of
photoelectric integrated acceleration seismic geophone technology".
A novel electro-optic integrated acceleration seismic geophone is presented in this paper and it is a new kind of
micro-opto-electro-mechanical system (MOEMS). The optical waveguide polarizer, M-Z interferometer, harmonic
oscillator system and waveguide phase modulator are integrated monolithically on silicon substrate with dimensions of
30mm×12mm×0.5mm. Mach-Zehnder waveguide interferometer of Si-based MOEMS acceleration seismic geophone is
researched and its optimization structure design is accomplished. The material of buffer layer and coating layer is K9
glass. Two Bak7 glass Y-branching waveguides with width of 4μm and thickness of 0.4μm, and six guide mirrors are
employed in interferometer. An S-shaped bend is used for the transition connecting two offset parallel waveguides in
Y-branching. Because it is difficulty to make the branching angle large using conventional Y-branching, we designed 90º
directional change by a vertical mirror facet to realize the special structure between measuring arm and reference arm.
The inner dielectric film of the mirror facet is aluminum plating. To prevent polarization state of TE mode polarized light
changed after passing through the aluminum film, 4 polarizers with length of 1mm have been used. The simulation
results performed in BMP agrees with the theoretical analysis well.
A novel electro-optic integrated acceleration seismic geophone is presented in this paper. In order to modulate the phase
of optical waveguide M-Z interferometer on silicon substrate, the method of acousto-optic phase modulation is proposed.
The acousto-optic phase modulator realizes phase modulation by passing the reference beam through a surface acoustic
wave (SAW) generated on a ZnO thin-film transducer driven by an interdigital transducer (IDT). The motivation and the
transmission of the SAW is researched and the principle of IDT is discussed. The refractive index change, generated by
the SAW is analyzed. On the basis of above analysis of acousto-optic phase modulation, considering the design demands
of the electro-optic integrated acceleration seismic geophone, optimum dimension parameters of the acousto-optic
modulation device, e.g., the number N of finger pairs, characteristic length L and interdigital period M is implemented.
So optimization structure design of the ZnO thin film and the structure of IDT are designed. Lots of theoretical and
experimental researches on preparation handicraft of ZnO thin film and IDT have been done and the acousto-optic phase
modulator is fabricated.
For high resolution application in seismic detection, the geophone should be smaller in size, more reliable and sensitive.
So a kind of photo-electronic integrated acceleration seismic detecting technology, which is novel and precise based on
waveguide M-Z interference, is presented. The principle of the photo-electronic integrated acceleration seismic geophone
is introduced in this paper. The seismometer is composed of a waveguide M-Z interferometer, a sensing element, a
modulation LD and signal processing system. The silicon crystal is adopted as the substrate. The core of the photoelectronic
integrated acceleration is the silicon harmonic oscillator, which is supported by four silicon beams and
integrated on the signal beam of the M-Z interferometer . The harmonic oscillator translates the acceleration information
of the external vibrational signal into phase variation of optical signal in the sensing arm, which is converted into optical
signal by M-Z interferometer, then PIN converts the optical signal into electric signal to process by the signal processing.
The experimental curve of seismometer frequency response is achieved.
For simultaneously detecting multi-parameters of blood in the clinical diagnosis, the analysis apparatus should be smaller
in size, more reliable and sensitive. So a kind of integrated bio-sensor for blood analysis based on Micro Total Analysis
System (μTAS) is presented. It provides modern bio-sensor prospect with a novel technology.
A multi-parameters of blood analysis integration sensor is μTAS bio-sensor based on 4 groups of interdigital array (IDA)microelectrodes. The IDA microelectrodes are fabricated on glass substrates by photography, film deposition and
other microfabrication techniques. Thin-film gold microelectrode with a thickness of 250nm is deposited on a chromium-adhesion
layer. The finger microelectrode width and space are both 10μm. The work space is 2×2cm2. The concentration
of Blood sugar, Total Cholesterol, Acetone body and Lactic acid is measured by detecting steady-state limiting
currents in IDA microelectrodes modified with enzymes on the "generate-collect" mode. Blood distribution structure is
designed and fabricated, to distribute blood and isolate reaction areas. By contrasting two kinds of process flow based on
lift-off and etching, etching is adopted to preparation method of microelectrode.
A multi-channel apparatus for current measurement is accompleted. The system characteristics of the bio-sensor are
tested. The curve of the apparatus time to current response is achieved by testing on real-time. The relationships between
parameter concentration and current are analyzed in detail. The experimental data indicates: current measurement
dimension 0~40μA, certainty of measurement 0.1μA, the performances of the bio-sensor meets design requirement.
Hybrid-integrated Optical acceleration seismometer and its digital signal processing system are researched and developed. The simple system figure of the seismometer is given. The principle of the seismometer is explicated. The seismometer is composed of a seismic mass,Integrated Optical Chips and a set of Michelson interferometer light path. The Michelson Integrated Optical Chips are critical parts among the sensor elements. The simple figure of the digital signal processing system is given. As an advanced quality digital signal processing (DSP) chip equipped with necessary circuits has been used in its digital signal processing system, a high accurate detection of the acceleration signal has been achieved and the environmental interference signal has been effectively compensated. Test results indicate that the accelerometer has better frequency response well above the resonant frequency, and the output signal is in correspondence with the input signal. The accelerometer also has better frequency response under the resonant frequency. At last, the curve of Seismometer frequency response is given.
A kind of novel optic strip waveguide phase modulator driven by a surface acoustic wave (SAW), applied to the signal modulation of photo-electronic-integrated accelerator based on Mach-Zehnder interferometry, present in this paper. The characteristic parameters of the acoustooptic modulator are investigated theoretically and experimentally. Measurements were performed on ZnO thin film deposited on Si substrate with f0=48MHz at λ0 = 1.3μm optical wavelength using K9 glass waveguide. The main parameters of the modulator is as following: the ZnO thin film with the dimensions of 5 mm x 0.8 mm x 0.003 mm; Interdigital transducer with the fingers of 17 pairs, the electrode aperture width of 4.46 mm and the interdigital period of 27.19 μm.
This paper describes a Michelson all-fiber acceleration seismic geophone with dual-optic routes. Compared with the single-optic route structure, dual-optic routes geophone exhibits wider frequency response range; meanwhile it also constrains the transverse vibration of the mass, incline and bend of the fiber more efficiently. The seismic geophone consists of Michelson interferometer, sensing element and signal processing system. An alternating current phase tracking (PTAC) homodyne scheme has been used to process output signal of the Michelson interferometer. Experimental results matches well with the theoretical prediction; the working frequency band is 5~535Hz; the acceleration sensitivity is 0.9rad/m/s2; and the non-distortion percentage is smaller than 0.7%.
A novel Si-based MOEMS acceleration seismic geophone, based on M-Z interferometry, is present in this paper. In one silicon chip, several elements including four silicon beams,seismic mass, a polarizer, M-Z waveguide interferometer and acousto-optic phase modulator are integrated. The working principle and the optimization structure design of the acceleration seismic geophone are given. The simulation result performed in FEM software ANSYS agrees with the theoretical analysis well. The main design parameters of the geophone system is as following: resonance frequency: 1353 Hz; phase detection sensitivity ΔΦ/a: 1.2×10-4rad/m/s2.
The hybrid-integrated optical acceleration seismic geophone is present for the first time in this paper. Double-Y branching guide, phase modulator and polarizers, which are integrated on the LiNbO3 substrate to constitute the Michelson interference chip, hardcore of the accelerometer, are analyzed and designed respectively. The chip is fabricated successfully and the lighting test is proceeding to check the quality of the chip. The waveguides' images of chip fabricated is presented. The results of and lighting test are given too.
A single-component dual-optic paths acceleration seismic geophone based on all-fiber Michelson interferometer is developed, which can detect the acceleration less than 0.01g. In order to obtain the elastic modulus changing of compliant cylinder after rolling fiber, the key component of the sensitive unit, a compressing test and a stretching test are carried out. And at the end of the paper a three-component acceleration seismic geophone based on the single-component one is discussed.
The 4X4 LiNbo3 optical wave-guide switch matrix , which is composed of five directional couplers, is designed. Alternative ? ? electrode structure is adopted for easier fabrication. The guides of switch matrix fabricated successfully are shown in this paper. Light testing is proceeded and the result is also shown .Some important switch matrix's performance are calculated theoretically as following: switch time 2.9ns; switch voltage 25.6v; insertion loss 7.0 17 dB.
Integrated-optic technology can provide compact and rugged fiber-optic sensors. In this paper, we first propose and demonstrate an optical integrated circuits (IC) device in the Ti:LiNbO3 for a fiber-optic accelerometer, including basic design concepts, fabrication techniques and waveguide components.
Fiber-optic sensors are maturing at a fast pace with multifunction integrated optics making many of these sensors practical. We first demonstrate hybrid integrated optical accelerometer system which combines the Ti:LiNbO3 chip and the polarization-maintaining fiber to pick up vibration signal. So this system has both advantages of integrated optics and fiber-optic sensors. This paper summarizes of architecture of hybrid integrated optical accelerometer.
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