檢測(cè)某些類型的非法物質(zhì)可能很困難,因?yàn)橛袝r(shí)在犯罪現(xiàn)場(chǎng)只會(huì)發(fā)現(xiàn)少量的藥物殘留呻纹,而這些藥物可能并不總是肉眼可見的堆生。法醫(yī)光源可作為一種無損和安全的方法,用于檢測(cè)一些常見的毒品或毒品殘留物雷酪,如可卡因或海洛因淑仆。盡管不同類型的殘留物在不同波長(zhǎng)的光下會(huì)發(fā)出熒光,但許多藥物殘留物在用犯罪分子發(fā)光時(shí)會(huì)發(fā)出熒光哥力。因此蔗怠,檢查人員在調(diào)查期間使用一系列波長(zhǎng)的光源來檢測(cè)藥物殘留非常重要墩弯。
當(dāng)特定波長(zhǎng)的可見光被某種物質(zhì)吸收,然后物質(zhì)發(fā)射不同波長(zhǎng)的光時(shí)寞射,就會(huì)發(fā)生熒光渔工。這種發(fā)射的熒光強(qiáng)度比產(chǎn)生熒光的激發(fā)光弱得多,因此使用濾光片來阻擋未被吸收的光桥温,以便觀察發(fā)射的熒光引矩。
Fluorescence occurs when visible light of a specific wavelength is absorbed by a substrate, which then emits light of a different wavelength. This emitted fluorescence is much weaker in intensity than the light that produced it, so filters are used to block out light not absorbed, in order for fluorescent emissions to be viewed.
UV光源產(chǎn)生肉眼不可見但產(chǎn)生可見UV熒光的光。不需要濾光器來觀察UV熒光侵浸,盡管可見光通濾光器也適用于該應(yīng)用旺韭。A UV light source generates light which is invisible to the naked eye but produces visible UV fluorescence. A filter is not required to view UV fluorescence although a visible pass filter is also suitable for this application.
上圖:可卡因在紫外光源照射下(透明紫外濾鏡)
上圖:可卡因在藍(lán)光445nm照射下, 530BP濾光片拍照
上圖:木質(zhì)表面海洛因殘留掏觉,在藍(lán)光445nm照射下区端, 530BP濾光片拍照