Abstract
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.
© 2009 Optical Society of America
Full Article | PDF ArticleMore Like This
S. Sudo, T. Ohtomo, and K. Otsuka
Appl. Opt. 54(22) 6832-6840 (2015)
Takayuki Ohtomo, Seiichi Sudo, and Kenju Otsuka
Appl. Opt. 48(3) 609-616 (2009)
Seiichi Sudo, Takayuki Ohtomo, Masao Iwamatsu, Tuyoshi Osada, and Kenju Otsuka
Appl. Opt. 51(3) 370-377 (2012)