scholarly journals Non-linear label-free imaging through a multimode graded index optical fibre

2020 ◽  
Vol 238 ◽  
pp. 04006
Author(s):  
Angel Cifuentes ◽  
Johanna Trägårdh ◽  
Tomáš Pikálek ◽  
Mojmír Šerý ◽  
Denis Akimov ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Second Harmonic ◽  
Speckle Pattern ◽  
Label Free ◽  
Graded Index ◽  
Non Linear ◽  
Wavefront Shaping ◽  
Microscopy Techniques ◽  
Anti Stokes ◽  
Made In

In recent years, great advances have been made in developing minimal footprint micro-endoscopes using multimode optical fibres (MMF) [1]. By employing wavefront shaping methods the seemingly random speckle pattern resulting from the guiding of coherent light through an MMF can be formed into a diffraction limited spot. This enables the implementation of multiple laser scanning techniques. In this work we show that this approach can be employed to realize label-free non-linear microscopy techniques such as coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG). Backscattered light makes epi-detection possible even though these processes preferably emit light in the direction of beam propagation [2].

scholarly journals Advanced Label-Free Laser Scanning Microscopy and Its Biological Imaging Application

2021 ◽  
Vol 11 (3) ◽  
pp. 1002
Author(s):  
Xue Wang ◽  
Xinchao Lu ◽  
Chengjun Huang
Keyword(s):  
Laser Scanning ◽  
Second Harmonic ◽  
Biological Tissues ◽  
Biological Imaging ◽  
Laser Scanning Microscopy ◽  
Scanning Microscopy ◽  
Localized Surface Plasmon ◽  
Label Free ◽  
Coherent Raman ◽  
Surface Plasmon Microscopy

By eliminating the photodamage and photobleaching induced by high intensity laser and fluorescent molecular, the label-free laser scanning microscopy shows powerful capability for imaging and dynamic tracing to biological tissues and cells. In this review, three types of label-free laser scanning microscopies: laser scanning coherent Raman scattering microscopy, second harmonic generation microscopy and scanning localized surface plasmon microscopy are discussed with their fundamentals, features and recent progress. The applications of label-free biological imaging of these laser scanning microscopies are also introduced. Finally, the performance of the microscopies is compared and the limitation and perspectives are summarized.

scholarly journals Depth resolved label-free multimodal optical imaging platform to study morpho-molecular composition of tissue

2019 ◽  
Vol 18 (5) ◽  
pp. 997-1008 ◽  
Author(s):  
Marco Andreana ◽  
Ryan Sentosa ◽  
Mikael T. Erkkilä ◽  
Wolfgang Drexler ◽  
Angelika Unterhuber
Keyword(s):  
Optical Coherence Tomography ◽  
Raman Scattering ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Structural Information ◽  
Second Harmonic ◽  
Label Free ◽  
Two Photon ◽  
Non Invasive ◽  
Anti Stokes

The presented multi-modal platform combines optical coherence tomography, two-photon excited fluorescence, second harmonic generation and anti-Stokes Raman scattering to provide molecular and structural information of tissue in a fast and non-invasive manner.

scholarly journals Nerve regeneration in the cephalopod mollusc Octopus vulgaris: label-free multiphoton microscopy as a tool for investigation

2018 ◽  
Vol 15 (141) ◽  
pp. 20170889 ◽  
Author(s):  
Pamela Imperadore ◽  
Ortrud Uckermann ◽  
Roberta Galli ◽  
Gerald Steiner ◽  
Matthias Kirsch ◽  
...  
Keyword(s):  
Second Harmonic ◽  
Multiphoton Microscopy ◽  
Scar Tissue ◽  
Octopus Vulgaris ◽  
Chemical Information ◽  
Label Free ◽  
Molecular Machinery ◽  
Staining Methods ◽  
Species Specific ◽  
Anti Stokes

Octopus and cephalopods are able to regenerate injured tissues. Recent advancements in the study of regeneration in cephalopods appear promising encompassing different approaches helping to decipher cellular and molecular machinery involved in the process. However, lack of specific markers to investigate degenerative/regenerative phenomena and inflammatory events occurring after damage is limiting these studies. Label-free multiphoton microscopy is applied for the first time to the transected pallial nerve of Octopus vulgaris . Various optical contrast methods including coherent anti-Stokes Raman scattering (CARS), endogenous two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) have been used. We detected cells and structures often not revealed with classical staining methods. CARS highlighted the involvement of haemocytes in building up scar tissue; CARS and TPEF facilitated the identification of degenerating fibres; SHG allowed visualization of fibrillary collagen, revealing the formation of a connective tissue bridge between the nerve stumps, likely involved in axon guidance. Using label-free multiphoton microscopy, we studied the regenerative events in octopus without using any other labelling techniques. These imaging methods provided extremely helpful morpho-chemical information to describe regeneration events. The techniques applied here are species-specific independent and should facilitate the comparison among various animal species.

Second Harmonic Imaging Microscopy: A New Non-Linear Optical Modality for Cell Membrane Physiology

2000 ◽  
Vol 6 (S2) ◽  
pp. 810-811
Author(s):  
Paul Campagnola ◽  
Aaron Lewis ◽  
Leslie M. Loew
Keyword(s):  
Confocal Microscopy ◽  
Laser Scanning ◽  
Second Harmonic ◽  
Laser Scanning Microscopy ◽  
Scanning Microscopy ◽  
Photon Absorption ◽  
Photon Flux ◽  
Two Photon ◽  
Non Linear ◽  
Linear Optical

Confocal microscopy is an excellent high resolution method to image fluorescently labeled cells. However, the use of confocal microscopy to monitor physiological events, such as membrane potential changes, in living cells is hampered by photobleaching and phototoxicity. To reduce the collateral damage from excitation of fluorescent probes outside the optical slice, Webb and co-workers introduced the use of two-photon excited (TPE) fluorescence in laser scanning microscopy.1 Two-photon absorption depends on the square of the incident light intensity; this has the effect of confining excitation to the plane of focus where the photon flux density is greatest. The wavelength of the exciting light is in the near infrared facilitating penetration of thick tissues. Due to these significant advantages this methodology is rapidly gaining popularity as a tool for live cell and tissue imaging.To further exploit non-linear optical processes in laser scanning microscopy, we have developed surface second harmonic generation (SHG) as a powerful new imaging modality.

scholarly journals Multimodal nonlinear endomicroscopic imaging probe using a double-core double-clad fiber and focus-combining micro-optical concept

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ekaterina Pshenay-Severin ◽  
Hyeonsoo Bae ◽  
Karl Reichwald ◽  
Gregor Matz ◽  
Jörg Bierlich ◽  
...  
Keyword(s):  
Second Harmonic ◽  
Numerical Aperture ◽  
Small Diameter ◽  
Field Of View ◽  
Tissue Imaging ◽  
Laser Source ◽  
High Peak Power ◽  
Label Free ◽  
Signal Collection ◽  
Non Linear

AbstractMultimodal non-linear microscopy combining coherent anti-Stokes Raman scattering, second harmonic generation, and two-photon excited fluorescence has proved to be a versatile and powerful tool enabling the label-free investigation of tissue structure, molecular composition, and correlation with function and disease status. For a routine medical application, the implementation of this approach into an in vivo imaging endoscope is required. However, this is a difficult task due to the requirements of a multicolour ultrashort laser delivery from a compact and robust laser source through a fiber with low losses and temporal synchronization, the efficient signal collection in epi-direction, the need for small-diameter but highly corrected endomicroobjectives of high numerical aperture and compact scanners. Here, we introduce an ultra-compact fiber-scanning endoscope platform for multimodal non-linear endomicroscopy in combination with a compact four-wave mixing based fiber laser. The heart of this fiber-scanning endoscope is an in-house custom-designed, single mode, double clad, double core pure silica fiber in combination with a 2.4 mm diameter NIR-dual-waveband corrected endomicroscopic objective of 0.55 numerical aperture and 180 µm field of view for non-linear imaging, allowing a background free, low-loss, high peak power laser delivery, and an efficient signal collection in backward direction. A linear diffractive optical grating overlays pump and Stokes laser foci across the full field of view, such that diffraction-limited performance is demonstrated for tissue imaging at one frame per second with sub-micron spatial resolution and at a high transmission of 65% from the laser to the specimen using a distal resonant fiber scanner.

scholarly journals Custom Multiphoton/Raman Microscopy Setup for Imaging and Characterization of Biological Samples

2019 ◽  
Vol 2 (2) ◽  
pp. 51 ◽  
Author(s):  
Marco Marchetti ◽  
Enrico Baria ◽  
Riccardo Cicchi ◽  
Francesco Saverio Pavone
Keyword(s):  
Laser Scanning ◽  
Ex Vivo ◽  
Second Harmonic ◽  
Biological Tissues ◽  
Molecular Organization ◽  
Chemical Information ◽  
Specific Information ◽  
Label Free ◽  
Wide Range ◽  
Experimental Apparatus

Modern optics offers several label-free microscopic and spectroscopic solutions which are useful for both imaging and pathological assessments of biological tissues. The possibility to obtain similar morphological and biochemical information with fast and label-free techniques is highly desirable, but no single optical modality is capable of obtaining all of the information provided by histological and immunohistochemical analyses. Integrated multimodal imaging offers the possibility of integrating morphological with functional-chemical information in a label-free modality, complementing the simple observation with multiple specific contrast mechanisms. Here, we developed a custom laser-scanning microscopic platform that combines confocal Raman spectroscopy with multimodal non-linear imaging, including Coherent Anti-Stokes Raman Scattering, Second-Harmonic Generation, Two-Photon Excited Fluorescence, and Fluorescence Lifetime Imaging Microscopy. The experimental apparatus is capable of high-resolution morphological imaging of the specimen, while also providing specific information about molecular organization, functional behavior, and molecular fingerprint. The system was successfully tested in the analysis of ex vivo tissues affected by urothelial carcinoma and by atherosclerosis, allowing us to multimodally characterize of the investigated specimen. Our results show a proof-of-principle demonstrating the potential of the presented multimodal approach, which could serve in a wide range of biological and biomedical applications.

scholarly journals Recent advances and applications of nonlinear optical microscopy: perspectives in cancer imaging

2018 ◽  
Author(s):  
A S M Waliullah
Keyword(s):  
Harmonic Generation ◽  
Cancer Diagnosis ◽  
High Performance ◽  
Second Harmonic ◽  
Cancer Imaging ◽  
Non Linear ◽  
Linear Optical ◽  
Third Harmonic Generation Microscopy ◽  
Anti Stokes ◽  
Microscopic Techniques

Background: Biomedical imaging is one of the important investigation processes for human diseases, especially in cancer diagnosis. Along with conventional light microscopic techniques, there are some high performance imaging systems are being used for cancer diagnosis, such as phase contrast microscopy, Optical coherence tomography, magnetic resonance imaging. But still these imaging modalities suffer from several limitations and medical facilities, research institutions started to use more specific and advanced microscopic techniques like, multi-photon fluorescence microscopy, Coherent anti-Stokes Raman scattering microscopy, second harmonic generation microscopy, third harmonic generation microscopy, etc. which are referred as non-linear optical microscopy.Methods: Literature searches from PubMed and google scholar related to recent development of non-linear optical microscopies and their applications on cancer diagnosis were chosen in this review.Results: After reviewing 93 related article, it was found that non-linear optical microscopies are playing a key role in the precise, rapid diagnosis, staging of different types of cancer. Conclusions: Non-linear optical microscopic modalities are not only limited to image the cancerous tissues, but also have the potential for commercialized non-invasive, real time endoscopic and laparoscopic diagnosis of cancer. If so, the physician could use these modalities for early diagnosis, surgery, and treatment. Thus way non-linear optical microscopic techniques could pioneer in cancer imaging area.

Imprecision of Laboratory Determinations and Diagnostic Accuracy: Theoretical Considerations

1974 ◽  
Vol 13 (03) ◽  
pp. 151-158 ◽  
Author(s):  
D. A. B. Lindbebo ◽  
Fr. R. Watson
Keyword(s):  
Mathematical Model ◽  
Diagnostic Accuracy ◽  
Diagnostic Process ◽  
Clinical Laboratories ◽  
Non Linear ◽  
Theoretical Considerations ◽  
Made In

Recent studies suggest the determinations of clinical laboratories must be made more precise than at present. This paper presents a means of examining benefits of improvement in precision. To do this we use a mathematical model of the effect upon the diagnostic process of imprecision in measurements and the influence upon these two of Importance of Diagnosis and Prevalence of Disease. The interaction of these effects is grossly non-linear. There is therefore no proper intuitive answer to questions involving these matters. The effects can always, however, be calculated.Including a great many assumptions the modeling suggests that improvements in precision of any determination ought probably to be made in hospital rather than screening laboratories, unless Importance of Diagnosis is extremely high.

Sign in / Sign up

Export Citation Format

Share Document