Micro-LED arrays: a tool for two-dimensional neuron stimulation

Poher, V.; Grossman, Nir; Kennedy, Gordon T.; Nikolić, Konstantin; Zhang, H X; Gong, Zheng; Drakakis, Emmanuel M.; Gu, Erdan; Dawson, Martin D.; French, Paul M. W.; Degenaar, Patrick; Neil, Mark A. A.

doi:10.1088/0022-3727/41/9/094014

Cited by 122 publications

(72 citation statements)

References 31 publications

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“…16 These cells could then be stimulated to fire action potentials by the use of a headmounted gallium nitride LED array (a similar design to modern virtual reality headsets) ( Figure 3). A unique feature of this approach is the potential to inhibit as well as excite action potentials.…”

Section: Optoelectronic Approachesmentioning

confidence: 99%

Current and future prospects for optoelectronic retinal prostheses

Dowling

2008

Eye

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There has been accelerating progress in the development of retinal prosthesis systems designed to partially restore vision to people with retinitis pigmentosa or macular degeneration. Current retinal prostheses can be divided into two types: those that receive power and information from passive or active photodiodes (optoelectronic systems) and those based on multielectrode arrays powered by cables or transcutaneous telemetry systems. Currently, four research groups have ongoing chronic implantation clinical studies, and two of these groups plan to have commercial retinal prosthesis systems available within the next 2 years. This paper reviews the development and current status of the most significant international retinal prosthesis research groups and discusses future prospects and issues associated with their retinal prosthesis systems.

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Section: Optoelectronic Approachesmentioning

confidence: 99%

Current and future prospects for optoelectronic retinal prostheses

Dowling

2008

Eye

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“…A 2D-VCSEL array would allow for selective stimulation of a nerve without mechanical repositioning of the laser and the individually addressable lasers gives the possibility to stimulate multiple sites simultaneously. This two-dimensional probing of neural networks has been demonstrated with GaN micro-LED arrays 20 , and is desired for example in chochlear implants 21 . Blue LEDs have recently been used in in vivo optogenetic experiments 22 , where VCSELs could offer additional advantages such as a low-divergent circular-symmetric output beam and improved high-speed performance.…”

Section: Introductionmentioning

confidence: 99%

Progress and challenges in electrically pumped GaN-based VCSELs

et al. 2016

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The Vertical-Cavity Surface-Emitting Laser (VCSEL) is an established optical source in short-distance optical communication links, computer mice and tailored infrared power heating systems. Its low power consumption, easy integration into two-dimensional arrays, and low-cost manufacturing also make this type of semiconductor laser suitable for application in areas such as high-resolution printing, medical applications, and general lighting. However, these applications require emission wavelengths in the blue-UV instead of the established infrared regime, which can be achieved by using GaN-based instead of GaAs-based materials. The development of GaN-based VCSELs is challenging, but during recent years several groups have managed to demonstrate electrically pumped GaN-based VCSELs with close to 1 mW of optical output power and threshold current densities between 3-16 kA/cm 2 . The performance is limited by challenges such as achieving high-reflectivity mirrors, vertical and lateral carrier confinement, efficient lateral current spreading, accurate cavity length control and lateral optical mode confinement. This paper summarizes different strategies to solve these issues in electrically pumped GaN-VCSELs together with state-of-the-art results. We will highlight our work on combined transverse current and optical mode confinement, where we show that many structures used for current confinement result in unintentionally optically anti-guided resonators. Such resonators can have a very high optical loss, which easily doubles the threshold gain for lasing. We will also present an alternative to the use of distributed Bragg reflectors as high-reflectivity mirrors, namely TiO2/air high contrast gratings (HCGs). Fabricated HCGs of this type show a high reflectivity (>95%) over a 25 nm wavelength span.

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“…In addition, there are also genetically encoded voltage indicators [5] and voltage-sensitive dyes [6] that precisely report the fast changes in the membrane potential allowing one to study the propagation of action potentials along the dendritic tree of a neuron via single [7][8][9] and twophoton excitation [10]. Multi-site fluorescence imaging can be achieved via single-photon wide-field illumination using a conventional light source, patterned illumination using holographic projection [11,12] or a micro-LED array [13]. However, using light with a shorter wavelength has limited penetration depth making it less preferred for in vivo studies of mammalian brains.…”

Section: Introductionmentioning

confidence: 99%

Efficient multi-site two-photon functional imaging of neuronal circuits

Castañares¹,

Gautam²,

Drury³

et al. 2016

Biomed. Opt. Express

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Two-photon imaging using high-speed multi-channel detectors is a promising approach for optical recording of cellular membrane dynamics at multiple sites. A main bottleneck of this technique is the limited number of photons captured within a short exposure time (~1ms). Here, we implement temporal gating to improve the two-photon fluorescence yield from holographically projected multiple foci whilst maintaining a biologically safe incident average power. We observed up to 6x improvement in the signal-to-noise ratio (SNR) in Fluorescein and cultured hippocampal neurons showing evoked calcium transients. With improved SNR, we could pave the way to achieving multi-site optical recording of fluorogenic probes with response times in the order of ~1ms.

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Micro-LED arrays: a tool for two-dimensional neuron stimulation

Cited by 122 publications

References 31 publications

Current and future prospects for optoelectronic retinal prostheses

Current and future prospects for optoelectronic retinal prostheses

Progress and challenges in electrically pumped GaN-based VCSELs

Efficient multi-site two-photon functional imaging of neuronal circuits

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