Wideband MOEMS for the Calibration of Optical Readout Systems

Abstract

The paper proposes a technology based on UV-LIGA process for microoptoelectromechanical systems (MOEMS) manufacturing. We used the original combination of materials and technological steps, in which any of the materials does not enter chemical reactions with each other, while all of them are weakly sensitive to the effects of oxygen plasma. This made it suitable for long-term etching in the oxygen plasma at low discharge power with the complete preservation of the original geometry, including small parts. The micromembranes were formed by thermal evaporation of Al. This simplified the technique compared to the classic UV-LIGA and guaranteed high quality and uniformity of the resulting structure. To demonstrate the complete process, a test MOEMS with electrostatic control was manufactured. On one chip, a set of micromembranes was created with different stiffness from 10 nm/V to 100 nm/V and various working ranges from 100 to 300 nm. All membranes have a flat frequency response without resonant peaks in the frequency range 0–200 kHz. The proposed technology potentially enables the manufacture of wide low-height membranes of complex geometry to create microoptic fiber sensors.

Low-Coherence Homodyne Interferometer for Sub-Megahertz Fiber Optic Sensor Readout

“…[ 14 , 15 , 16 , 17 ]. The working principle of such sensors is based on the change in the optical path difference of the optical waves in the FOS under an external influence, for example, the temperature dependence of the index of refraction [ 18 , 19 ], the membrane shift for pressure and vibrations [ 20 ], and so on.…”

Fiber Optic Impact Location System Based on a Tracking Tandem Low-Coherence Interferometer

“…[ 16 , 17 , 18 , 19 ]. The working principle of such sensors is based on the change of their optical length at external influence, for example in temperature sensors, the temperature dependence of the index of refraction [ 20 ] and in pressure and vibration sensors, the membrane shift [ 21 , 22 ]. This change is detected further by means of the optical system of registration.…”

Метод Детектирования Малых Колебаний На Основе Гомодинной Демодуляции С Тандемным Низкокогерентным Интерферометром

“…В настоящей работе предложен метод детектирования малых колебаний оптической задержки в интерференционных волоконно-оптических сенсорах, объединяющий алгоритм гомодинной демодуляции и низкокогерентную интерферометрию, что позволило развязать сенсорную зону и зону модуляции, что, в свою очередь, сняло ограничение на расстояние до сенсора от источника и системы детектирования. собой интерферометр, в частности внутриволоконный резонатор типа Фабри−Перо или оптомикромеханическую систему [20], но в рамках настоящей работы стояла задача апробации метода, что требовало возможности контролируемого воздействия на сенсор с заранее известными параметрами. Предложенный вариант позволял задавать колебание разности длин плеч сенсорного интерферометра с требуемой амплитудой в широком диапазоне частот.…”