Next generation photostimulation system using tunable laser

在本研究中，我们研制了一种波长可调的光刺激装置。利用外延型周期偏振晶体可以产生~400 nm~~500 nm的二次谐波。因此，该设备可以光刺激绿色荧光蛋白、通道视紫红质和许多其他光敏分子。在该系统中，我们还配备了一对钽酸锂(KTN)晶体作为可调透镜，这是一种通过电压改变折射率的电光设备。通过改变施加在可调谐KTN透镜上的电压，焦距在~20微秒内改变。换焦速度比传统的压电式调焦器快约500~1000倍。该技术不仅适用于包括脑科学在内的科学研究，也适用于激光加工、激光测量等工业领域。

In this study we developed a tunable wavelength photo-stimulation equipment. We could generate second harmonic waves ranging from ~400 nm to ~500 nm with a fun-out type periodically polarized crystal. So this equipment can photo-stimulate GFP, channelrhodopsin, and many other photosensitive molecules. In the system we also equipped a pair of potassium tantalate niobate (KTN) crystals as a tunable lens, an electro-optic device that changes its refractive index by voltage. By changing the voltage which applied to the tunable KTN lens, focus changed within ~20 microseconds. The speed of focus change was about 500~1000 times faster than that of the conventional piezo focuser. This technique can be applicable not only to scientific researches including brain science but also industrial field such as laser processing and laser measurement.