Mr. Jozsua Fodor Profile

Jozsua Fodor

Optical Engineer & Designer at Ecole Normale Supérieure

SPIE Involvement:

Author

Publications (5)

Proceedings Article | 30 May 2022 Presentation

Custom-access serial holography for the 3D measurement of spike correlations between neurons in mouse visual cortex

Walther Akemann, Sébastien Wolf, Vincent Villette, Benjamin Mathieu, Astou Tangara, Jozsua Fodor, Cathie Ventalon, Jean-François Léger, Stéphane Dieudonné, Laurent Bourdieu

Proceedings Volume PC12144, PC1214402 (2022) https://doi.org/10.1117/12.2620939

KEYWORDS: Neurons, Visual cortex, Holography, 3D metrology, Temporal resolution, Multiphoton microscopy, Microscopy, In vivo imaging, Brain, Acousto-optics

Read Abstract +

Custom-access serial holography (CASH) is a new method for optical recording of neuronal activity in 3D at high speed in-vivo. Our implementation allows random access of 20 cells at 1 kHz up to 200 cells at 0.1 kHz in head-fixed behaving mice across a cortical space of 500 x 500 x 500 m3 size. Using fast acousto-optic spatial light modulation, every single laser pulse of a 40 kHz regenerative amplifier is individually patterned to serially access a selection of target cells with a square 5x5 spot excitation volume covering the cell body and, for the prevention of recording artefacts, the surrounding space in anticipation of the cell displacements during animal behavior. The recorded activity is corrected for neuropil signaling by weighted subtraction of a neuropil reference signal obtained by interleaved sampling of neuropil activity close to each cell. We performed 3D-CASH recordings of GCaMP6f expressing neurons in layer 2/3 and 5 of mouse primary visual cortex in response to moving contrast gratings and applied deconvolution to estimate spikes. Thanks to the fast recording permit by 3D-CASH, the cortical laminar structure is revealed in the temporal organization of the activity: pairwise correlation was higher between intralaminar vs. interlaminar neuron pairs; principal component analysis of the correlation matrix revealed a component assigning weights of opposite sign to neurons in different layers; closest follower spikes occurred with higher probability in a neuron of the same layer. 3D-CASH allows also following the response to the temporal periodicity of the stimulus, which features a phasic (R1) and a non-phasic component (R0). R1/R0 values are broadly distributed with weak bimodality resembling the transition between pure non-phasic response (complex receptive field) to phasic response (simple receptive field). Our data validate thus 3D-CASH as a method for assessing neuronal activity in 3D-distributed cortical circuits at high sampling rate.

Proceedings Article | 2 August 2004 Paper

Massively parallel interferometry: towards the all-integrated lambdameter

Jozsua Fodor, Jorge Garcia-Marquez, Yves Surrel

Proceedings Volume 5531, (2004) https://doi.org/10.1117/12.556325

KEYWORDS: Interferometry, Phase measurement, Sensors, Interferometers, Mirrors, Thermal effects, CCD image sensors, Cameras, Detection and tracking algorithms, Fabry–Perot interferometers

Read Abstract +

Proceedings Article | 10 January 2002 Paper

Read/write demonstrator of rewritable holographic memory card system

Emoeke Loerincz, Ferenc Ujhelyi, Pal Koppa, A. Kerekes, Gabor Szarvas, Gabor Erdei, Jozsua Fodor, Sz. Mike, Attila Sueto, Peter Varhegyi, P. Ramanujam, Soeren Hvilsted

Proceedings Volume 4342, (2002) https://doi.org/10.1117/12.453409

KEYWORDS: Holography, Objectives, Spatial light modulators, Holograms, Polarization, Optical storage, Mirrors, Data storage, Semiconductor lasers, Reflectivity

Read Abstract +

Proceedings Article | 24 October 2000 Paper

Design of high-numerical-aperture Fourier objectives for holographic memory card writing/reading equipment

Gabor Erdei, Jozsua Fodor, Peter Kallo, Gabor Szarvas, Ferenc Ujhelyi

Proceedings Volume 4093, (2000) https://doi.org/10.1117/12.405239

KEYWORDS: Objectives, Aspheric lenses, Spatial light modulators, Distortion, Charge-coupled devices, Tolerancing, Optical design, Holography, Fourier transforms, Holograms

Read Abstract +

Proceedings Article | 2 October 2000 Paper

Optical system of holographic memory card writing/reading equipment

Gabor Erdei, Gabor Szarvas, Emoeke Loerincz, Jozsua Fodor, Ferenc Ujhelyi, Pal Koppa, Peter Varhegyi, Peter Richter

Proceedings Volume 4092, (2000) https://doi.org/10.1117/12.402415

KEYWORDS: Polarization, Spatial light modulators, Holograms, Holography, Diffraction, Charge-coupled devices, Objectives, Data storage, Mirrors, Polymers

Read Abstract +

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years