A laser hazard evaluation compares the potential laser exposure to the maximum permissible exposure (MPE). Direct intrabeam viewing of a collimated laser beam produces a minimally sized retinal image. Viewing other laser sources often produces a larger retinal image known as an extended source. An optical limiter is designed to protect the eye from direct laser exposure through a combination of absorption and scattering, producing an extended source. Diode lasers in combination with diffusers also produce extended sources when viewed at a close distance. A substantial increase in the MPE is allowed for extended sources, based on the size of the retinal image. The larger retinal image produced by the optical limiter does not exhibit a Gaussian or top-hat profile, making it often difficult to judge its effectiveness. Therefore, it is necessary to define methods to quantify the reduction in hazard. The partial areas method that is currently used overestimates the reduction in hazard from a single extended source with a strong central peak.

中文翻译：

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计算扩展源的有效源大小

激光危害评估将潜在的激光暴露与最大允许暴露 (MPE) 进行比较。准直激光束的直接束内观察产生最小尺寸的视网膜图像。查看其他激光源通常会产生更大的视网膜图像，称为扩展源。光学限制器旨在通过吸收和散射的组合保护眼睛免受直接激光照射，从而产生扩展源。当近距离观察时，二极管激光器与漫射器相结合也能产生扩展的光源。根据视网膜图像的大小，对于扩展源，允许显着增加 MPE。光学限幅器产生的较大的视网膜图像不呈现高斯或礼帽轮廓，因此通常难以判断其有效性。所以，有必要确定量化危害减少的方法。当前使用的局部区域方法高估了具有强中心峰的单个扩展源的危害减少。