In the field of biology and medicine, observation object of the microscope has been changing from the thin specimen
to the thick living tissue. Furthermore, observation of the internal structure of a living tissue is also desired by low
invasion. However, the real structure of a phase object with three-dimensional distribution such as a living tissue is
difficult to observe, because of the influence of the phase distribution before and behind of observation position. We
enabled observation of the internal structure of living tissue without stain, by adding a new function to reduce the
influence of phase distribution to our Retardation-Modulated differential interference contrast (RM-DIC) microscope
system.
In the image of laser scanning confocal microscope, an edge of a weak phase object is sometimes enhanced as bright and/or dark line. This phenomenon is thought to be caused by the interference effect of diffractive light from the edge. The imaging characteristics of this type of microscope are regarded as a product of the optical sectioning characteristics (I-Z response) and the optical property of its imaging system. The I-Z curve decreases monotonically with depth (Z) which is determined by a diameter of pinhole and a numerical aperture (NA) of imaging system. Analyzing partially coherent imaging system under the weak phase approximation, we found that intensity image generated with increasing a defocus in observing weak phase only object of step-like figure. Accordingly the peak in optical transfer function (OTF) arose at some point of specific defocused depth in response to the spatial frequency of an observing object, so we observe an edge enhancement in this type of microscope. In experiment, we used OLS1100 laser scanning microscope (Olympus Co., Ltd.) with NA=0.95 in 100-power objective. Light source is Ar-ion laser of 488nm. We prepare rectangular samples which have 5.0 micron in width, and 50 nm in depth. We observed edge enhancement in auto-focus mode for the above samples. After measuring defocus characteristics of I-Z response we evaluate our theory in good agreement for the edge enhancement on the image of laser scanning confocal microscope.
The retardation modulated DIC (RM-DIC) method is proposed for extracting phase information from a DIC image by analyzing the partial coherent theory, which is applied to quantitative measurements of phase objects. The experimental results using RM-DIC method are presented and the quantitative analysis of the phase grating are presented.
The retardation modulated DIC is proposed for extracting phase information from a DIC image by analyzing the partial coherent theory, which is applied to DIC image enhancement and phase information extraction.
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.