What are the types of lasers used for optical modules?

There are several types of lasers that are commonly used in optical modules, including:

1. Fabry-Perot lasers: These are the most common type of laser used in optical modules. They are simple and cost-effective, making them ideal for a wide range of applications.

2. Distributed feedback (DFB) lasers: These lasers are more complex and expensive than Fabry-Perot lasers, but they offer higher performance and stability. They are often used in high-speed communication systems.

3. Vertical-cavity surface-emitting lasers (VCSELs): These lasers emit light perpendicular to the surface of the chip, making them ideal for applications where space is limited. They are commonly used in data communication and sensing applications.

4. Quantum cascade lasers: These lasers are used in applications that require high-power and tunable wavelengths, such as spectroscopy and gas sensing.

5. External cavity lasers: These lasers use an external cavity to control the wavelength of the emitted light, making them highly tunable and suitable for a wide range of applications.

- Vertical-cavity surface-emitting lasers (VCSELs) are semiconductor lasers that emit light perpendicular to the surface of the chip. They are used in short-range optical communications applications, such as data centers and fiber-to-the-home (FTTH).
- Edge-emitting lasers (EELs) are semiconductor lasers that emit light parallel to the surface of the chip. They are used in long-range optical communications applications, such as undersea cables and intercontinental fiber-optic networks.
- Fiber Bragg gratings (FBGs) are optical filters that are written into optical fibers. They are used to reflect light of specific wavelengths, which can be used to create lasers, multiplexers, and other optical devices.
- Semiconductor optical amplifiers (SOAs) are optical amplifiers that are made from semiconductor materials. They are used to amplify optical signals, which can be used to increase the range of optical communications systems.

‘Laser’ evolved from the abbreviation of LASER (Light Amplification by Stimulated Emission of Radiation). Laser is a kind of coherent light, with the characteristics of the same frequency, the same vibration direction and the same phase (or the phase difference remains constant). Optical communication system, to a large extent, depends on high quality laser light source https://www.glsun.com/article-p102-types-of-lasers-for-optical-modules.html