<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
</head>
<body>
<div class="moz-forward-container">
<div style="font-family: arial, helvetica, sans-serif; font-size:
12pt; color: #000000">
<div data-marker="__QUOTED_TEXT__">
<div style="font-family:'arial' , 'helvetica' ,
sans-serif;font-size:12pt;color:#000000">
<div>
<div>
<div><strong
style="text-align:justify;font-family:'times new
roman' , 'new york' , 'times' ,
serif;font-size:12pt"><b><span
style="font-size:14pt;font-family:'century
gothic' , sans-serif;color:#993300" lang="EN-GB">utorak,
16. svibnja 2023., u 11:00 sati</span></b></strong><br>
<div>
<div>
<div id="zimbraEditorContainer" class="24">
<div style="color:rgb( 0 , 0 , 0
);font-family:'times new roman' , 'new york' ,
'times' ,
serif;font-size:12pt;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(
255 , 255 , 255
);text-decoration:none;text-align:justify"><strong><b><span
style="font-size:14pt;font-family:'century gothic' ,
sans-serif;color:#993300" lang="EN-GB"></span></b></strong><br>
</div>
<div
style="text-indent:0px;background-color:rgb(
255 , 255 , 255 );text-align:justify"><font
face="Times New Roman, serif"
color="#55913c"><span
style="font-size:21.3333px"><b>Holography
and coherent optics</b></span></font><span
style="color:rgb( 85 , 145 , 60
);font-family:'times new roman' ,
serif;font-size:21.3333px"> </span></div>
<div style="color:rgb( 0 , 0 , 0
);font-family:'arial' , 'helvetica' ,
sans-serif;font-size:12pt;text-indent:0px;background-color:rgb(
255 , 255 , 255 );text-align:justify"><span
style="color:rgb( 0 , 0 , 0
);font-family:'century gothic' ,
sans-serif;font-size:16px;font-style:normal;font-weight:normal;letter-spacing:normal;text-transform:none;white-space:normal;word-spacing:0px"><span
style="font-size:18.6667px"><b><b
style="color:#000000;font-family:'times
new roman' , 'new york' , 'times' ,
serif;font-size:16px;font-style:normal;letter-spacing:normal;text-align:center;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:#ffffff"><span
style="font-size:14pt;font-family:'century gothic' , sans-serif"
lang="EN-GB">Dr. sc. </span></b></b></span></span><font
face="century gothic, sans-serif"><span
style="font-size:18.6667px"><b>Hrvoje
Skenderović</b></span></font></div>
<div style="color:rgb( 0 , 0 , 0
);font-family:'arial' , 'helvetica' ,
sans-serif;font-size:12pt;text-indent:0px;background-color:rgb(
255 , 255 , 255 );text-align:justify"><font
face="century gothic, sans-serif"><span
style="font-size:14.6667px"><b>Institute
of Physics</b></span></font><b
style="color:rgb( 0 , 0 , 0
);font-family:'times new roman' , 'new york'
, 'times' ,
serif;font-size:12pt;font-style:normal;font-weight:normal;letter-spacing:normal;text-transform:none;white-space:normal;word-spacing:0px"><span
style="font-size:11pt;font-family:'century
gothic' , sans-serif" lang="EN-GB"> </span></b><span
style="font-size:small;font-family:'arial'"></span></div>
<div
style="text-indent:0px;background-color:rgb(
255 , 255 , 255 );text-align:left">
<div id="pageContainer" class="page"
style="padding:10px 10px 0px
0px;width:700px;min-height:500px">
<div class="entrytext "
style="line-height:22px">
<p style="text-align:justify;margin:0px"><span
style="text-align:left"><span
style="font-size:14px">The topic of
the talk is research in the field of
Digital Holography and connected
themes. Especially, implementation
of holographic measurements with
scanning single photon avalanche
detector (SPAD), as well as
time-averaged digital holography
(TADH) is presented. In TADH
measurements, holograms of a
vibrating object are recorded,
usually in such a way that the
exposure period of the camera
recording the hologram is many times
greater than the period of
vibrations. We examined the error in
the reconstruction if the exposure
time is only a few times greater
than the oscillation period and if
it is a non-integer ratio of the two
times. In the following, we have
shown that it is possible to obtain
an accurate hologram even when the
exposure is only half the
oscillation period with a known
phase. Finally, we have given a
procedure for determining the
unknown oscillation period and phase
with several short exposures. All
these numerical calculations were
confirmed by experimental
measurements with real objects. </span><br>
</span></p>
<p style="margin:0px;text-align:justify"><span
style="font-size:14px">We also
investigated the differences in
sampling and nonlinearities in
holography using a SPAD detector and a
camera. We have shown how it is
possible to determine the optimal
sampling using a scanning detector.
Also, the standard camera mainly works
with an 8-bit image, that is, it has
256 gray levels, which easily leads to
saturation in the recording, or to the
appearance of non-linear members in
the reconstruction of the hologram. In
contrast, SPAD as a detector has an
infinite dynamic range.</span></p>
<p style="text-align:justify;margin:0px"><span
style="text-align:left;font-size:14px"></span></p>
<p style="margin:0px;text-align:justify"><span
style="font-size:14px">An experiment
dealing with application of quantum
light in holography is also discussed.
The objective is to use individual
photons in a classic holographic setup
and see if they can be used to obtain
a hologram and if visibility improves
compared to classic source of the same
(very low) intensity. Since holography
is based on the interference of two
light beams, and in the case of
individual photons we a photon can not
be split at the BS, the possibility of
interference is not clear a priori.
Also, there is a problem with the
phase, which is indeterminate for
individual photons. It is shown that a
hologram can be recorded, amplitude
and phase reconstruction can be
obtained, and the SNR is better
compared to classical light of the
same intensity.</span></p>
<div style="color:rgb( 0 , 0 , 0
);font-family:'arial' , 'helvetica' ,
sans-serif;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-transform:none;white-space:normal;word-spacing:0px;text-align:justify"><br>
</div>
<div style="color:rgb( 0 , 0 , 0
);font-family:'arial' , 'helvetica' ,
sans-serif;font-size:12pt;text-align:justify"><br
data-mce-bogus="1">
</div>
<div style="color:rgb( 0 , 0 , 0
);font-family:'arial' , 'helvetica' ,
sans-serif;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-transform:none;white-space:normal;word-spacing:0px">
<div>Predsjednik Znanstvenog vijeća
Instituta za fiziku</div>
<div>dr. sc. Damir Starešinić<br>
<br>
<br>
<br>
<br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<br>
</div>
</div>
</div>
</body>
</html>