Optical filters are devices that selectively transmit or block specific wavelengths of light. They are commonly used in various applications, such as photography, scientific research, and telecommunications. By allowing only certain colors or frequencies of light to pass through, optical filters can enhance image quality, improve visibility, or protect sensitive equipment. There are different types of optical filters, including bandpass filters, which allow a specific range of wavelengths to pass, and notch filters, which block a particular wavelength while allowing others to pass. These filters can be made from glass, plastic, or other materials, depending on their intended use.