Title :
Analytical modeling of micromachined resonator sensor activated by cw laser irradiation
Author_Institution :
Dept. of Mechatronics & Precision Eng., Tohoku Univ., Sendai, Japan
Abstract :
Analytical modeling of micromachined mechanical resonator sensor self-excited by cw laser irradiation is presented. The optical feedback through the photothermal effect in the interference fringe generates the self-excited vibration of the micromachined beams. The optical interference, thermal diffusion in the resonator and mechanical dynamics of the resonator are combined to maintain the oscillation. From the analysis, the following phenomena of the self-excited vibration have been explained: (1) threshold in light intensity to generate the vibration, (2) saturation of the vibration amplitude, (3) periodicity of the vibration excitation as a function of the displacement of the feedback mirror, (4) bistability of the vibration center, and (5) frequency shift of the vibration
Keywords :
laser beam applications; light interference; micromechanical resonators; microsensors; optical feedback; photothermal effects; semiconductor device models; thermoelasticity; vibrations; analytical model; cw laser irradiation activation; feedback mirror displacement; interference fringe; light intensity threshold; mechanical dynamics; micromachined beams; micromachined resonator sensor; optical feedback; optical interference; photothermal effect; self-excited vibration; thermal diffusion; thermoelastic bending; vibration amplitude saturation; vibration center bistability; vibration excitation periodicity; vibration frequency shift; Analytical models; Interference; Laser beams; Laser feedback; Laser modes; Mechanical sensors; Optical feedback; Optical resonators; Photothermal effects; Vibrations;
Conference_Titel :
Solid State Sensors and Actuators, 1997. TRANSDUCERS '97 Chicago., 1997 International Conference on
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-3829-4
DOI :
10.1109/SENSOR.1997.613593
