光學(xué)顯微與電子成像1(編輯修改稿)
2025-01-18 13:35 本頁面
【文章內(nèi)容簡介】 illuminated by every point in the light source ? A given point in the light source illuminates every point in the specimen. Koeher(科勒 ) Illumination System 照明系統(tǒng) Koehler illumination, invented in 1893 by August Koehler How to achieve Koeher Illumination? 23 Koeher(科勒 ) Illumination System 科勒照明 的實(shí)現(xiàn)：把 光源 的發(fā)光體正好擺在聚光鏡下方的 前焦平面 Koeher照明光路 ? 發(fā)光體上點(diǎn)光源 變成一束 平行光 （光源上一點(diǎn)照明樣品的每一點(diǎn)） ? 整個(gè)發(fā)光體 變成無數(shù)束 平行光（樣品上一點(diǎn)由光源每一點(diǎn)照明） 樣品上無燈絲像，無條紋 24 Koeher(科勒 ) Illumination System Field planes and Aperture planes eyepieces eyepiece telescope 孔徑光闌 視場光闌 25 Diaphragm 光闌 分為 孔徑光闌 和 視場光闌、 漸暈光闌和雜消光光闌等 孔徑光闌 ：用于確定輻射測量的面積的光闌 （改變成象光束的大小和控制進(jìn)入光學(xué)系統(tǒng)的光通亮） 視場光闌： 限制成像范圍的光闌 26 Field stop diaphragm (視場光闌 ) ? Limit the area and the position of illumination on the specimen. ? Limit the amount of light cast ? Eliminate flares and ghosting, leading to sharper images. ? Can Not adjust the NA of the condenser lens and objective ? Can Not affect the Resolution Function of the field stop diaphragm in Microscope 27 Aperture diaphragm (孔徑光闌 ) ?Limits the projection of the light source (filament), which enables adjustment of brightness of the field of view. ?Adjust the angle of incidence. ?Adjust the contrast resolution and focal depth. ?Can Not affect the viewing field Function of the aperture diaphragm in Microscope 28 Aperture diaphragm Function of the aperture diaphragm in Microscope Adjust the NA of the condenser lens NA= NA= NA= 29 Aperture diaphragm Function of the aperture diaphragm in Microscope Adjust the contrast resolution 聚光鏡 孔徑光闌 =NA 聚光鏡孔徑光闌 = 聚光鏡孔徑光闌 = 聚光鏡 孔徑光闌的大小縮小到等于所用物鏡出射光瞳的 2/3或4/5效果好 , 這是在最大分辯率與最佳反差間所作的折衷 . 30 Adjusting Microscope for Koeher Illumination 1. Preliminaries ? specimen slide ? co
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