Improved Michelson Interferometer Research Articles

High-sensitivity high-temperature sensor based on multi-microspheres improved Michelson interferometer

We experimentally demonstrated two high-sensitivity high-temperature sensors based on in-line Michelson interferometers with the array of microspheres, which were fabricated by a simple fusion splicing technique. The devices have the highest temperature sensitivity of 0.139 nm/°C and 0.166 nm/°C, respectively, within the temperature region between 100 °C and 800 °C. The increase in the number of microspheres can improve temperature sensitivity while reducing the size of the sensor has been proved. It can be a new way to improve the performance of high-temperature fiber-optic sensors.

Ultra-compact silicon-microcap based improved Michelson interferometer high-temperature sensor.

An ultra-short high-temperature fiber-optic sensor based on a silicon-microcap created by a single-mode fiber (SMF) and simple fusion splicing technology is proposed and experimentally demonstrated. A section of the SMF with a silicon-microcap at one end is connected to the "peanut" structure to build the microcap-based optical fiber improved Michelson interferometer (MI). The optimal discharge parameters of microcap and length of SMF has been investigated to achieve the best extinction ratio of 6.61 dB. The size of this microcap-based improved MI sensor is 560 µm and about 18 times shorter compared to the current fiber tip interferometers (about 10 mm). Meanwhile, it showed good robustness during the two heating-cooling cycles and the duration period stability test at 900 °C. This microcap-based improved MI sensor with the smaller size, simple fabrication, low cost, high reliability, and good linearity within a large dynamic range is beneficial to practical temperature measurement and massive production.

On relationship between annealing treatment and magnetostriction behavior of Fe–16Cr–2.5Mo damping alloy

Abstract The damping capacity of Fe–16Cr–2.5Mo damping alloy was analyzed using a cantilever device. The magnetostriction property was measured using an improved Michelson interferometer. The domain morphology was optically observed using a magneto-fluid. Magnetomechanical Hysteresis Effect (MMHE) was discussed by analyzing the relationship between the magnetostriction performance and the annealing process of the alloy. The results show that the variation of saturate magnetostriction coefficient is quite consistent with that of the damping capacity of the annealed samples. With the local internal stress widely distributing in the annealed alloy, both the domain’s mobility and their structure vary with the increasing annealing temperature and time. The local internal stress not only pins the domain mobility but also makes the domain structure disorder. The domain size and the number of 90° magnetic domains are responsible for the highest damping capacity of the sample annealed at 900 °C for 1 h. However, with the prolonged annealing time, the number of 90° domain decreases sharply and more heterogeneous domains appears in the alloy. The spike domains can also pin domain-walls.

Experimental study of Fourier transform spectrometer based on MEMS micro-mirror

We propose a new Fourier transform spectrometer based on programmable microelectromechanical systems (MEMS) micro-mirror and an improved Michelson interferometer. The principle of the spectrometer is theoretically analyzed. A signal acquisition unit and an experimental set-up are designed. The spectrum of the polychromatic light source is obtained at a slantwise reflector angle of 0.238°. The spectrum is analyzed by this system within the near infrared. The experimental results show that the spectral accuracy is less than 3 nm, and the signal-to-noise ratio (SNR) is 18 dB. The spectral resolution is less than 16 nm.

Fabrication of large area two-dimensional nonlinear photonic lattices using improved Michelson interferometer

We demonstrate an approach for easy fabrication of large area two-dimensional nonlinear photonic lattices in photorefractive crystal using the laser interference technique with an improved Michelson interferometer. The experimental setup of this method is relatively simple and inexpensive. It can be applied in almost any optical laboratories. Large area (about 28.2mm2) two-dimensional square nonlinear photonic lattices have been produced in an iron-doped lithium niobate photorefractive crystal. We analyze the induced nonlinear photonic lattices by plane wave guiding, Brillouin-zone spectroscopy and far field diffraction pattern imaging. The period of the induced photonic lattices can be dominated easily. The induced photonic lattices can exist stably for a long time in the photorefractive crystal.

Optically induced three-dimensional nonlinear photonic lattices in LiNbO 3:Fe crystal

We fabricate three-dimensional nonlinear photonic lattices in self-defocusing iron-doped lithium niobate photorefractive crystal for the first time by an improved Michelson interferometer device. The experimental setup is simple and inexpensive. The period of the induced photonic lattices can be dominated easily. We analyze the three-dimensional nonlinear photonic lattices by plane wave guiding and far field diffraction pattern imaging. The induced nonlinear photonic lattices can exist stably for a long time in the photorefractive crystal.

OCT 시스템의 SNR 향상을 위한 간섭계 개선에 관한 연구

As a noninvasive imaging method, optical coherence tomography system has been extensively studied because it has some advantages such as imaging of high resolution, low cost, and compact size configuration. In order to improve the SNR of OCT system, two types of interferometers were configured and then, we compared simulation with measurement of reference sample. In the OCT system is configured with Michelson interferometer, the contrast of cross-sectional image is reduced with low SNR detection which is due to loss of feedback interference signal from light source part. Also, in order to image measured data with real time, image processing program is constructed. From results of simulation, it is confirmed that improved Michelson interferometer is improved about 10[dB] with a 50 : 50 fiber coupler. And from the measurement of reference sample, about 5[dB] is improved with a 50 : 50 fiber coupler. It is confirmed that the OCT system is configured with the improved Michelson interferometer which has a good distinctive cross-sectional image due to higher contrast.

Processing of interferometric signals for a CTE measurement system

An improved Michelson interferometer and signal analysis system was developed for the CTE (coefficient of thermal expansion) measurement of thin plates and thin walled tubes. Computer based methods based on phase angle calculation to interpret the interference fringes were derived and compared to a manual chart recording approach. The computer recording system provided an automatic signal interpretation with minimal electronic circuitry. Algorithms for finding the signal phase angle were developed. Matrix operations were performed on the stored data. Requirements for signal stability and electronic noise were determined. A fixed parameter approach maps data onto a reference ellipse and eliminates the effect of ellipse size changes. Results for fused silica and composite plates and tubes in the axial direction agree well with prior work and predictions from classical composite plate theory.