Two-photon excitation of 2,5-diphenyloxazole using a low power green solid state laser

Two-photon optogenetics enables selectively stimulating individual cells for manipulating neuronal ensembles. As the general photostimulation strategy, the patterned two-photon excitation has enabled millisecond-timescale activation for single or multiple neurons, but its activation efficiency is suffered from high laser power due to low beam-modulation efficiency. Here, we develop a high-efficiency beam-shaping method based on the Gerchberg-Saxton (GS) algorithm with spherical-distribution initial phase (GSSIP) to reduce the patterned two-photon excitation speckles and intensity. It can well control the phase of shaped beams to attain speckle-free accurate patterned illumination with an improvement of 44.21% in the modulation efficiency compared with that of the traditional GS algorithm. A combination of temporal focusing and the GSSIP algorithm (TF-GSSIP) achieves patterned focusing through 500-μm-thickness mouse brain slices, which is 2.5 times deeper than the penetration depth of TF-GS with the same signal-to-noise ratio (SNR). With our method, the laser power can be reduced to only 55.56% of that with traditional method (the temporal focusing with GS, TF-GS) to reliably evoke GCaMP6s response in C1V1-expressing cultured neurons with single-cell resolution. Besides, the photostimulation efficiency is remarkably increased by 80.19% at the same excitation density of 0.27 mW/μm2. This two-photon stimulation method with low-power, reliable and patterned illumination may pave the way for analyzing neural circuits and neural coding and decoding mechanism.

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Multiple-photon excitation imaging with an all-solid-state laser

10.1117/12.239552 ◽

1996 ◽

Cited By ~ 11

Author(s):

David L. Wokosin ◽

Victoria F. Centonze ◽

John G. White ◽

Steven N. Hird ◽

S. Sepsenwol ◽

...

Keyword(s):

Solid State ◽

Solid State Laser ◽

State Laser ◽

Photon Excitation

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Study of the Process of Additive Formation of Low-Melting Materials by Means of a Low-Power Solid-State Laser

Proceedings of Southwest State University ◽

10.21869/2223-1560-2020-24-4-8-17 ◽

2021 ◽

Vol 24 (4) ◽

pp. 8-17

Author(s):

V. V. Kuts ◽

V. S. Merkulov ◽

A. N. Grechukhin

Keyword(s):

Solid State ◽

Low Power ◽

Construction Material ◽

Experimental Studies ◽

Solid State Laser ◽

Experiment Planning ◽

State Laser ◽

Additive Method ◽

Melting Technique ◽

Series Of Experiments

Purpose of research. Testing a method for additive formation of low-melting materials through the use of a low-power solid-state (ytterbium) laser (maximum power 50 W). A series of experiments have been carried. As a result of those experiments, the elements of shaping mode have been obtained. They ensure the shaping of products without complete melting of the construction material while preserving the shape of a rough workpiece. Thus, the possibility of using this type of equipment for shaping products from low-melting materials in an additive way has been confirmed, which is the basis for further research on other materials, as well as the additional use of a shielding atmosphere. Methods. Methods of experiment planning and empirical data processing have been used for conducting experiments. Results. The possibility of using a low-power laser for the set tasks has been confirmed. Values ranges of shaping modes have been obtained, which ensure the formation of products made of low-melting materials by the partial melting technique through an additive method. Conclusion. The experimental studies have shown that a low-power solid-state laser can be applied for shaping products made of low-melting materials using an additive method. Applying the results of this study will allow further development of additive shaping of other metals (such as copper or aluminum), for which it is necessary to upgrade the equipment in terms of creating a shielding atmosphere in the melt zone, as well as increasing the laser power.

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Solid state red biphotonic excited emission from small dipolar fluorophores

Journal of Materials Chemistry C ◽

10.1039/c5tc03465e ◽

2016 ◽

Vol 4 (4) ◽

pp. 766-779 ◽

Cited By ~ 27

Author(s):

Martin Ipuy ◽

Yuan-Yuan Liao ◽

Erwann Jeanneau ◽

Patrice L. Baldeck ◽

Yann Bretonnière ◽

...

Keyword(s):

Solid State ◽

Penetration Depth ◽

Near Infrared ◽

Emission Wavelength ◽

Infrared Range ◽

Two Photon ◽

Photon Excitation ◽

Near Infrared Range ◽

Two Photon Excitation

Dyes emitting in the solid state in the red or near-infrared range are much sought after for application in bioimaging especially if the long emission wavelength can be combined with two-photon excitation to provide unique contrast and penetration depth.

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