High-performance Tm–silica fibre lasers operating at 1.9
μ
m when pumped at 1319 or 1064
nm have been Q-switched using a rotating mirror mounted at an asymmetric angle. Pumping by 1319
nm gives ...better performance compared with 1064
nm pumping due to greater excited state absorption (ESA) at 1064
nm. A short Q-switched pulse duration of 25
ns and a peak pulse power of about 2.7
kW has been obtained from a 1.8
m fibre for 3.5
W launched pump power at 1.3
μ
m. The Q-switch performance has been studied for variation of fibre length and shown that the optimum length under these pumping conditions is around 2
m.
In this report, we propose a method to reconstruct 3D shape of small object from microscope images. We use a microscope system which can observe the object obliquely and multi-directionally by a ...rotating mirror head. At first, a geometrical model of the microscope is derived. Next, we project each observed image to a plane assumed in a space using texture mapping. Then, each point on the plane can be evaluated about its validity by checking overlapping situation of projected appearance on the plane. By translating the plane parallel in the space, 3D shape is obtained as a set of valid points in thespace. In this report, color information and edge information is used as appearance features for this method.
本報告では、回転ヘッドを有する顕微鏡を用いて撮影した多方向からの撮影画像群から3次元形状を獲得する一手法を提案する。まず、使用する顕微鏡における被写体の3次元空間と撮影画像群との幾何学関係をモデル化する。次に、空間内に仮定した平面上に投影した撮影像を利用して見え方の重なりを評価し、その平面上の各点が物体表面上の点として有効か無効かを判断する方法である。本報告では見え方の特徴として色情報、およびエッジ情報を利用した重なり判定を導入し、CGで使用されるテクスチャマッピング機能を利用して計算機上に実装し3次元形状再構成を試みた。さらに、それらの結果を考察し、両情報を併用した手法についても報告する。
We propose a new type of nonlinear optical loop mirror that can reduce nonreciprocal phase shifts due to external vibration. We experimentally confirm its excellent vibration by all-optical ...time-division demultiplexing of 100-Gb/s optical signal.
We report a rotating-mirror scanning camera system based on a galvanometer and a CCD camera. This system improves the imaging speed by placing a series of paralleled images on the sensor of the ...camera so that multiple images are acquired during one single exposure; thus, the frame rate of the CCD camera does not limit the temporal resolution of recorded events. The camera is implemented on a custom designed light-sheet microscopy and aims to improve the imaging speed while the high spatial resolution is still retained on the light-sheet microscope.
One trial is reported on producing deformed lines of an object scanned by a laser beam, that is, socalled deformed grating patterns. Such properties inherent in a laser beam as being narrow in width ...and high in intensity can be effectively utilized for the purpose. With the aim of getting appropriate patterns, geometrical relations between a rotating mirror and an incident light are investigated, and a practical scanning apparatus is deviced and manufactured as a prototype. The photographic pattern of the object with deformed grating lines reveals Moire fringes showing contours mapping when superimposed by a reference grating. Experimental applications with one pair of these patterns show that cross sections of the object can be drawn and that piling up these sections can reproduce the original shape of the subject body.
Abstract
We propose a new scheme to prepare macroscopic entanglement between two rotating mirrors using dissipative atomic reservoir in a double-Laguerre–Gaussian-cavity system. The two-level atomic ...system driven by a strong field, acts as a single pathway of Bogoliubov dissipation to push the two original cavity modes into the desirable entangled state under the near-resonant conditions. Successively, the photon–photon entanglement can be transferred to mirror–mirror entanglement through the exchange of orbital angular momentum. In essence, the macroscopic entanglement is originated from the dissipative atomic reservoir rather than the radiation torque, thereby it is usually robust against environmental noises. The present scheme provides a feasible way to realize stable entanglement between spatially separated mirrors with high capacity, which may find potential applications in remote quantum communications.
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