Welcome to Optical Sensors!

 Our interest in optical sensors is in sensing force, acceleration, pressure, temperature, gas flow, or strain for rocket and jet engine applications. The importance of optical sensors in future engine sensing systems is widely recognized[see R. Baumbick, in Integrated Optics and Optoelectronics II, SPIE volume 1374, pp. 238-250, 1990 and S. Dasgupta, in Integrated Optics and Optoelectronics II, SPIE, volume 1374, pp. 211-222, 1990].

We are investigating optical fiber-coupled sensors formed by combining optical waveguides and micromachined- micromechanical structures on the same silicon substrate. These sensor devices combine the advantages of both optical fiber sensors[see T. G. Giallorenzi, Optical Fiber Sensor Technology, IEEE Journal of Quantum Electronics, Volume QE-18, p. 626, 1982] a nd of micromechanical structures formed by micromachining[see K. E. Petersen, Silicon as a Mechanical Material, Proceedings of the IEEE, Volume 70, p. 420, 1982]. These sensors are intended to be remotely located using optical fibers in electrically host ile environments as shown in the figure below.

Schematic of Optical Fiber Sensor Configuration



Optical sensors offer numerous advantages over conventional electronic sensors, including the ability to function in higher temperature environments, immunity to electromagnetic interference, electrical passivity, good sensitivity with high dynamic range, and low-cost manufacturing. Using micromachining allows control of the sensitivity of the device to external variables by tailoring dimensions of the micromechanical structure.

Our optical sensors use optical channel waveguides fabricated on a layer of silicon dioxide on a silicon wafer. Light in the channel waveguides is confined in-plane by the refractive index profile of the films and guided around the surface by photolithog raphically patterned etched ridges in the film. These channel waveguides function like miniature optical fibers in that they conduct light to various locations on the substrate.

Currently, we are working on the design and fabrication of three different optical sensors:


Optical Waveguide Pressure Sensors

Optical MicroMachined Cantilever Beam Accelerometer

Optical Fiber-MEMS Pressure Sensor

List of Papers on Optical Sensors

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