Multiwaveguide implantable probe for light delivery to sets of distributed brain targets.
Multiwaveguide implantable probe for light delivery to sets of distributed brain targets.
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DOI：
10.1364/ol.35.004133
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发表时间：
2010-12-15
期刊：
影响因子：
3.6
通讯作者：
Fonstad CG
中科院分区：
文献类型：
--
作者：
Zorzos AN;Boyden ES;Fonstad CG
光纤通常被插入到脑等活组织中，以便将光传递到神经科学和神经工程应用的深层目标，如光遗传学，在光遗传学中，光被用来激活或沉默表达特定光敏蛋白的神经元。然而，光纤仅限于将光传输到大脑三维结构中的单个目标。我们在这里展示了一种多波导探头，能够沿着探针轴独立地向多个目标传送光，从而实现对多组分布式脑目标的多功能光学控制。1.45厘米长的探头是以360微米宽阵列的形式制成的，该阵列由12个平行的氮氧化硅(SiON)多模波导包覆SiO_2和铝；也可以轻松地制造出定制尺寸的探头。波导阵列在输入端接受来自一组光源的光，并将光沿每个波导引导到铝角镜，该镜有效地将光偏离探针轴。每个阶段的光损耗都很小(输入耦合损耗，0.4±0.3分贝；弯曲损耗，可以忽略不计；传播损耗，外散射法为3.1±1分贝/厘米，切回法为3.2±0.4分贝/厘米；角镜损耗，1.5±0.4分贝)；例如，与5毫瓦光源耦合的波导将向深度为1厘米的目标提供超过1.5毫瓦的辐射。
Optical fibers are commonly inserted into living tissues such as the brain in order to deliver light to deep targets for neuroscientific and neuroengineering applications such as optogenetics, in which light is used to activate or silence neurons expressing specific photosensitive proteins. However, an optical fiber is limited to delivering light to a single target within the three-dimensional structure of the brain. We here demonstrate a multi-waveguide probe capable of independently delivering light to multiple targets along the probe axis, thus enabling versatile optical control of sets of distributed brain targets. The 1.45 cm long probe is microfabricated in the form of a 360 micron-wide array of 12 parallel silicon oxynitride (SiON) multi-mode wave-guides clad with SiO2 and coated with aluminum; probes of custom dimensions are easily created as well. The waveguide array accepts light from a set of sources at the input end, and guides the light down each waveguide to an aluminum corner mirror that efficiently deflects light away from the probe axis. Light losses at each stage are small (input coupling loss, 0.4 ± 0.3 dB; bend loss, negligible; propagation loss, 3.1 ± 1 dB/cm using the out-scattering method and 3.2 ± 0.4 dB/cm using the cut-back method; corner mirror loss, 1.5 ± 0.4 dB); a waveguide coupled, for example, to a 5 mW source will deliver over 1.5 mW to a target at a depth of 1 cm.