We demonstrate and analyze a novel self-mixing laser particle sizing instrument using a He-Ne laser centered at around
632.8 nm and output power is 35 mW. A single mode fiber is used to deliver the incident light to the sample cell and the
fiber probe is worked as an optode. The scattered light is collected by the same fiber and re-injected into the laser.
Experimental investigations are presented for particle sizing using polystyrene particles in water from 100 to 400 nm in
diameter. Diameter of the scattering particle can be obtained by analyzing the optical power spectrum which is related to
the autocorrelation of the measured scattering intensity. The result has a good agreement with theory. As a significant
improvement, we gather the back-scattering light using a fiber optic probe accomplishes a task that is almost impossible
using conventional optics because the multiple scattering in a concentrated opaque suspension. Fiber optics also has the
advantages of being less prone to damage, less expensive and allowing for remote access in transmitting and collecting
light.
In this paper, a packaged erbium-doped fiber amplifier (EDFA) is integrated into a fiber ring to form an erbium-doped fiber ring (EDFR) laser which is applied to measure the particle size based on the self-mixing Doppler effect. A detailed analysis is addressed to introduce the measurement principle, and the obtained results demonstrate that the diameter of the Brownian particles in water can be measured by detect the variations of the intensity and frequency of the fiber laser. This technique can be used in biology, process engineering and chemistry.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.