[OPTICAL REVIEW Vol. 3, No. 2 (1996) 135-138]

Temperature Characteristics of Vibrating Type Sensor Using Micromachined Optical Fiber-Tip

Hironori KUMAZAKI,1 Seiki INABA1 and Kazuhiro HANE2

1Department of Electrical Engineering, Gifu National College of Technology, Motosu, Gifu, 501-04 Japan, 2Department of Mechatronics and Precision Engineering, Faculty of Engineering, Tohoku University, Aramaki-Aoba, Aoba-ku, Sendai, 980-77 Japan

(Received December 11, 1995; Accepted February 5, 1996)

An optical sensor using a quartz core microcantilever was fabricated by etching clad layer from optical fiber. The temperature dependence of the resonance frequency of this sensor was measured in atmosphere and water. The temperature coefficient of the resonance frequency in water was 1.3×10-3/°C, which was about one order larger than that (2.3×10-4/°C) in atmosphere. This was caused by increase of additional mass due to temperature dependence of the viscosity of water, while, the increase of the resonance frequency in atmosphere was caused by temperature dependence of Young's modulus of the quartz core. These results were evaluated theoretically using a “string-of-beads” model.

Key words : optical fiber, micromachine, photothermal effect, vibrating type sensor, temperature dependence