Under astigmatism even narrow parallel light beams will not combine into one point . 有象散存在時甚至很窄的平行光束都不能會聚在一點。
A parabolic concave mirror can converge parallel light rays to its focus , and also collimate light rays that pass through its focus 拋物面凹鏡會把平行而來的光線聚集在一點焦點,亦會把源自焦點的光線平行向外反射。
A parabolic concave mirror can converge parallel light rays to its focus , and also collimate light rays that pass through its focus 拋物面凹鏡會把平行而來的光線聚集在一點(焦點) ,亦會把源自焦點的光線平行向外反射。
When voltage is applied , however , these same molecules arrange themselves in a specific direction in such a way as to permit parallel light to pass through the glass 當液晶體份子任意地排列時,光線就不能透過玻璃.但當液晶體份子排列成某一方向,平衡的光線就可透過玻璃
A type of small - sized interferometer is reported , which makes use of the coupling of optical fiber and gradient index lens ( grin ) to form parallel light beams 摘要介紹一種超小型光纖導光干涉儀,它利用光纖和自聚焦透鏡的耦合來形成平行光路,利用半反和全反光學膜片分光。