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(a) Laser focusing optics LINOS 033486. (b) Opto-mechanical assembly built using a standard lens tube system for mounting the laser focusing optics to a camera device, with diaphragm at the optics entrance.
Source publication
Recently, we developed a simple theoretical model for the estimation of the irradiance distribution at the focal plane of commercial off-the-shelf (COTS) camera lenses in case of laser illumination. The purpose of such a model is to predict the incapacitation of imaging sensors when irradiated by laser light. The model is based on closed-form equat...
Citations
... To find the quantity ν hd , we equate Equation (12) (MPE S ) and Equation (25) (laser irradiance at the lens) and obtain where * is defined by [17]; * = min 1, √2 ...
... However, in the case of the MDE S , things are more complicated. The MDE S is given by Equation (17), which leads, together with Equation (25), to the following equation to be solved in order to obtain the ν hd : MDE S ( ) and thus apply the diffraction pa ern of a truncated Gaussian beam for our calculations, e.g., see Reference [22]. The form of this diffraction pa ern depends on the value of the truncation factor, , and consists of a central lobe that can be approximated by a Gaussian distribution and diffraction rings of lower power similar to the Airy diffraction pa ern. ...
... In an earlier work, we compared the calculated spatial light distribution in the focal plane of a camera lens, based on our theoretical model, with the output of the optical design software FRED [25]. We showed that the results of our theoretical model are comparable with the simulated results. ...
Laser safety is an important topic. Everybody working with lasers has to follow the long-established occupational safety rules to prevent people from eye damage by accidental irradiation. These rules comprise, for example, the calculation of the Maximum Permissible Exposure (MPE), as well as the corresponding laser hazard distance, the so-called Nominal Ocular Hazard Distance (NOHD). At exposure levels below the MPE, laser eye dazzling may occur and is described by a quite new concept, leading to definitions such as the Maximum Dazzle Exposure (MDE) and to its corresponding Nominal Ocular Dazzle Distance (NODD). In earlier work, we defined exposure limits for sensors corresponding to those for the human eye: The Maximum Permissible Exposure for a Sensor, MPES, and the Maximum Dazzle Exposure for a Sensor, MDES. In this publication, we report on our continuative work concerning the laser hazard distances arising from these exposure limits. In contrast to the human eye, unexpected results occur for electro-optical imaging systems: For laser irradiances exceeding the exposure limit, MPES, it can happen that the laser hazard zone does not extend directly from the laser source, but only from a specific distance to it. This means that some scenarios are possible where an electro-optical imaging sensor may be in danger of getting damaged within a certain distance to the laser source but is safe from damage when located close to the laser source. This is in contrast to laser eye safety, where it is assumed that the laser hazard zone always extends directly from the laser source. Furthermore, we provide closed-form equations in order to estimate laser hazard distances related to the damaging and dazzling of the electro-optical imaging systems.
