What is the main difference between fixed and dynamic filters in laser systems?

The main difference between fixed and dynamic filters in laser systems lies in their functionality and adaptability. Fixed filters are designed to have a specific transmission characteristic, meaning they allow certain wavelengths of light to pass through while blocking others, without changing their properties. They are static in nature and do not respond to varying conditions, such as different laser outputs or environmental factors.

On the other hand, dynamic filters are capable of adjusting their transmission characteristics in real-time based on the input light conditions. This allows them to selectively filter different wavelengths as needed, providing versatility in applications where the wavelength of the laser can change or where precise control over the wavelengths is required. This adaptability is a key advantage of dynamic filters.

In contrast to the other choices, those options either misrepresent the characteristics of fixed and dynamic filters or focus on their durability rather than their operational differences. Therefore, recognizing that the distinction lies primarily in the ability of dynamic filters to adjust to varying wavelengths while fixed filters maintain a constant state underlines the correct answer.