What is the primary characteristic of a fixed filter?

A fixed filter is designed to absorb a specific wavelength of light while allowing other wavelengths to pass through. This characteristic makes them valuable in various applications, particularly in laser safety, where there is a need to protect against specific wavelengths that may be hazardous while allowing safe wavelengths to transmit through.

These filters are crucial in settings where precise wavelength management is required, such as in laboratories or medical facilities using lasers. By targeting a specific wavelength, a fixed filter can effectively mitigate risks associated with laser exposure, ensuring safety for both operators and patients.

Understanding this characteristic is important when working with lasers, as it underlines the necessity of using the right filters to ensure protection from laser radiation, which can cause harm if appropriate safety measures are not implemented.