Determination of velocity of self-mobile phytoplankton using a self-mixing thin-slice solid-state laser.
We present an analysis of the shoulder-shaped power spectrum observed in the modulated laser output due to feedback light scattered from dynamic changes in self-mobile phytoplankton with flagella in seawater performed using a self-mixing laser Doppler vibrometry system. The power spectrum occasionally has shoulder-shaped broad frequency components superimposed on a Lorentz-type spectrum. This reflects the translational motion of phytoplankton moving across the beam-focus area. The velocity of phytoplankton in the focus area can be obtained by applying a curve fitting procedure to the power spectrum. Moreover, the average velocity and the velocity distribution of phytoplankton can be determined from curve fitting of the long-term power spectrum.
Sudo
Seiichi
S
Department of Physics, Tokyo City University, Tamazutsumi, Setagaya, Tokyo 158-8557, Japan. sudo@ph.ns.tcu.ac.jp
Ohtomo
Takayuki
T
Takahashi
Yohei
Y
Oishi
Tomohiko
T
Otsuka
Kenju
K
D004867:Equipment Design; D019544:Equipment Failure Analysis; D017078:Laser-Doppler Flowmetry / Q000295:instrumentation*; D053844:Lasers, Solid-State; D009038:Motion; D009068:Movement / Q000502:physiology*; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation*; D010839:Phytoplankton / Q000502:physiology*