INVESTIGATION ON LASER-DRIVEN MICROMACHINES USING OPTICAL FILTERS

提出了用激光波长差独立判别光热振动的方法。本研究进行了以下几个方面的研究.制作了光学干涉滤光片的微图形，悬臂梁仅在穿过该滤光片的激光束中被独立激发。实验证实，悬臂梁仅由特定波长的激光束振动。它是充分可能的独立控制通过这种技术，它似乎是可能的，光学致动器增加了自由度。2.将光学滤波器固定到悬臂梁本身，并且制造仅通过光吸收特定波长的激光束而振动的悬臂梁。悬臂梁由其他波长的激光束轻微激发。在这种情况下，需要使用形状记忆合金等作为悬臂梁的材料.通过叠加反相位激光的照射，使悬臂梁的光热振动停止.制作了厘米级的激光诱导机器人。采用光电二极管和单片机组成的机器人可以在崎岖的路面上沿激光轴线沿着直线运动.光纤是有用的，因为光学设置简单。对光纤作为滤波器进行了初步的实验研究，并利用反应等离子体刻蚀减薄包层的单模布拉格光栅光纤研制了可调谐波长滤波器。通过控制光栅的有效折射率或周期，实现了反射波长的移动。

The photothermal vibration independently discriminated by the difference between the wavelengths of laser beams is proposed. Several studies were performed as follows.1. The micro pattern of optical interference filter was produced, and cantilever beam was independently excited only in the laser beam which penetrated this filter. It was confirmed experimentally that the cantilever beam was vibrated only by the laser beam of the specific wavelength. It is sufficiently possible to control independently by this technique, and it seems to be possible that the optical actuator increased the degree of freedom.2. The optical filter was fixed to the cantilever beam itself, and the cantilever beam which was vibrated only by the laser beam of specific wavelength by light absorption was manufactured. The cantilever beam was slightly excited by laser beam of other wavelength. It is necessary to use shape memory alloys or so as the material of the cantilever beam in this case.3. The photothermal vibration of the cantilever was stopped by superimposing the anti-phase laser irradiation.4. Laser induced robots with cm-size were produced. The robot having photo-diodes and one chip micro computer can move straightly along the laser axis on the rugged road.5. Optical fiber is useful because of simpleness of optical setting. Elementary experiments on the fiber as optical filters were performed in order to Tunable wavelength filters were developed by using a single-mode Bragg grating fiber with a cladding thinned by reactive plasma etching. The reflection wavelength shifts were demonstrated by controlling the effective refractive index or the period of the grating.