When selecting a narrow linewidth laser, several key factors should be considered to ensure that it meets the specific requirements of the application. These factors include:

l Linewidth: The required linewidth depends on the application. For example, high-resolution spectroscopy may require a linewidth of less than 1 MHz, while less demanding applications may be able to tolerate a wider linewidth.

l Output power: The laser's output power should be sufficient for the intended use. For example, a laser used for cutting or drilling materials will require a higher output power than a laser used for spectroscopy.

l Wavelength: The laser's wavelength should be appropriate for the application. For example, a laser used for eye surgery will typically have a wavelength of 1064 nm, while a laser used for material processing may have a wavelength of 532 nm.

l Stability: The laser's frequency and power should be stable over time. This is particularly important for applications that require precise control of the laser's output, such as interferometry and holography.

l Cost: The cost of the laser is an important consideration, especially for large-scale applications. There are a wide range of narrow linewidth lasers available, with varying costs depending on the specifications and features.