scholarly journals Reflection-mode time-reversed ultrasonically encoded optical focusing into turbid media

2011 ◽  
Vol 16 (8) ◽  
pp. 080505 ◽  
Author(s):  
Puxiang Lai ◽  
Xiao Xu ◽  
Honglin Liu ◽  
Yuta Suzuki ◽  
Lihong V. Wang
Keyword(s):  
Turbid Media ◽  
Reflection Mode ◽  
Optical Focusing

scholarly journals Implementation of an Off-Axis Digital Optical Phase Conjugation System for Turbidity Suppression on Scattering Medium

2020 ◽  
Vol 10 (3) ◽  
pp. 875 ◽  
Author(s):  
Kai Zhang ◽  
Zhiyang Wang ◽  
Haihan Zhao ◽  
Chao Liu ◽  
Haoyun Zhang ◽  
...  
Keyword(s):  
Biological Tissue ◽  
Phase Conjugation ◽  
Turbid Media ◽  
Acquisition Time ◽  
Optical Phase Conjugation ◽  
Scattering Medium ◽  
Conjugation System ◽  
Optical Phase ◽  
Conjugate Reduction ◽  
Optical Focusing

Due to the light scattering effect, it is difficult to directly achieve optical focusing and imaging in turbid media, such as milk and biological tissue. The turbidity suppression of a scattering medium and control of light through the scattering medium are important for imaging on biological tissue or biophotonics. Optical phase conjugation is a novel technology on turbidity suppression by directly creating phase conjugation light waves to form time-reversed light. In this work, we report a digital optical phase conjugation system based on off-axis holography. Compared with traditional digital optical phase conjugation methods, the off-axis holography acquires the conjugation phase using only one interference image, obviously saving photo acquisition time. Furthermore, we tested the optical phase conjugate reduction performance of this system and also achieved optical focusing through the diffuser. We also proved that the reversing of random scattering in turbid media is achievable by phase conjugation.

scholarly journals Digital reflection-mode time-reversed ultrasonically encoded (TRUE) optical focusing

2014 ◽  
Author(s):  
Yuta Suzuki ◽  
Jian Wei Tay ◽  
Qiang Yang ◽  
Lihong Wang
Keyword(s):  
Reflection Mode ◽  
Optical Focusing

scholarly journals Modeling of iterative time-reversed ultrasonically-encoded optical focusing in a reflection mode

2021 ◽  
Author(s):  
Jian Wang ◽  
Hanpeng Liang ◽  
Jiawei Luo ◽  
Ye Bolin ◽  
Yuecheng Shen
Keyword(s):  
Reflection Mode ◽  
Optical Focusing

scholarly journals Fast optical wavefront engineering for controlling light propagation in dynamic turbid media

2019 ◽  
Vol 12 (04) ◽  
pp. 1930007 ◽  
Author(s):  
Meiyun Xia ◽  
Deyu Li ◽  
Ling Wang ◽  
Daifa Wang
Keyword(s):  
Optical Tweezers ◽  
Biological Tissue ◽  
Light Propagation ◽  
Optical Excitation ◽  
Mean Free Path ◽  
Turbid Media ◽  
Research Progress ◽  
Scattering Media ◽  
Wavefront Distortion ◽  
Optical Focusing

While propagating inside the strongly scattering biological tissue, photons lose their incident directions beyond one transport mean free path (TMFP, [Formula: see text]1 millimeter (mm)), which makes it challenging to achieve optical focusing or clear imaging deep inside tissue. By manipulating many degrees of the incident optical wavefront, the latest optical wavefront engineering (WFE) technology compensates the wavefront distortions caused by the scattering media and thus is toward breaking this physical limit, bringing bright perspective to many applications deep inside tissue, e.g., high resolution functional/molecular imaging, optical excitation (optogenetics) and optical tweezers. However, inside the dynamic turbid media such as the biological tissue, the wavefront distortion is a fast and continuously changing process whose decorrelation rate is on timescales from milliseconds (ms) to microseconds ([Formula: see text]s), or even faster. This requires that the WFE technology should be capable of beating this rapid process. In this review, we discuss the major challenges faced by the WFE technology due to the fast decorrelation of dynamic turbid media such as living tissue when achieving light focusing/imaging and summarize the research progress achieved to date to overcome these challenges.

An improved design for an Scanning Tunnelling Microscope (STM) for use in a Transmission Electron Microscope (TEM)

1991 ◽  
Vol 49 ◽  
pp. 384-385
Author(s):  
W.K. Lo ◽  
J.C.H. Spence
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Mechanical Stability ◽  
Scanning Tunnelling Microscope ◽  
Reflection Mode ◽  
Specimen Holder ◽  
Transmission Electron ◽  
Scanning Tunnelling ◽  
Improved Design

An improved design for a combination Scanning Tunnelling Microscope/TEM specimen holder is presented. It is based on earlier versions which have been used to test the usefulness of such a device. As with the earlier versions, this holder is meant to replace the standard double-tilt specimen holder of an unmodified Philips 400T TEM. It allows the sample to be imaged simultaneously by both the STM and the TEM when the TEM is operated in the reflection mode (see figure 1).The resolution of a STM is determined by its tip radii as well as its stability. This places strict limitations on the mechanical stability of the tip with respect to the sample. In this STM the piezoelectric tube scanner is rigidly mounted inside the endcap of the STM holder. The tip coarse approach to the sample (z-direction) is provided by an Inchworm which is located outside the TEM vacuum.

A size reduced reflection-mode phase shifter

2005 ◽  
Vol 47 (5) ◽  
pp. 457-459 ◽  
Author(s):  
Kae-Oh Sun ◽  
Chih-Chuan Yen ◽  
Daniel van der Weide
Keyword(s):  
Phase Shifter ◽  
Reflection Mode
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