There are two main approaches to achieving single-mode operation and a narrow linewidth:

• Distributed Feedback (DFB) Lasers: These lasers incorporate a grating structure within the laser cavity. This grating provides selective feedback, favoring a specific wavelength and suppressing others. Imagine the grating acting like a filter, allowing only a specific color of light to pass through and amplify efficiently.
• Distributed Bragg Reflector (DBR) Lasers: Similar to DFB lasers, DBR lasers utilize gratings. However, these gratings are placed at the ends of the laser cavity, acting as mirrors that reflect a narrow range of wavelengths and suppress others. This creates a resonant cavity that favors a single, desired wavelength.

By promoting single-mode operation and minimizing noise through careful design, narrow linewidth lasers achieve a highly pure, single-color output. For more information about narrow linewidth laser please click：https://www.cq-smart.com/narrow-linewidth-laser.