DFB laser is one type of semiconductor lasers. DFB lasers use the Bragg reflection of a diffraction grating formed along an active waveguide to unify the laser longitudinal mode. DFB provides high wavelength stability and narrow linewidth.
A DFB laser is a laser diode or optical fiber laser. DFB Laser has a low linewidth grating that extends throughout the cavity rather than simply at the opposite edges. DFB Laser are single-frequency lasers, with short linewidth and effective side modes.
DFB Laser Linewidth:
Since the cavity length of a DFB is rather short, the DFB Laser Linewidth are typically in the 1 MHz to 10 MHz range.
Here we list the DFB Laser linewidths for different DFB lasers from Different suppliers.
| Company Name | DFB Laser Product Name | Linewidth | Product Link | Wavelength & Output Power | Note |
| Laser Diode Source | 1550nm DFB Laser (400kHz), 8mW | 400kHz | RLS/EP1550-NLW-400 | 1550nm 8mW | Eblana's EP1550-NLW-B |
| INPHENIX INC | inphenix 1310nm -1660nm 3mW-20mW | 50kHz | DFB Laser 1310nm-1660nm | 1310nm 1520nm 1550nm 1660nm | USA Company |
| Thorlabs, Inc | 1555nm 1642nm-1654nm | 50kHz | DFB1550 DFB1642 DFB1650P | 1555nm 1642nm-1654nm | Butterfly Package |
| INNOLUME | 968nm-986nm 1300nm-1330nm | 1 MHz | DFB09XX000YY030MFXXX | 1120nm-1200nm 1200nm-1280nm | DORTMUND | GERMANY |
| NANOPLUS | 760nm - 14000 nm | 3 MHz | standard for DFB laser | 760.8nm 1278.8nm 1392.0nm | SLD FP |
| Toptica | Single-frequency laser distributed-feedback | 500 kHz | DFB pro | 633 nm, 760 nm .. 3500 nm | Mode-hop free tuning |
| BeamQ | 1550nm 40mW DFB 14PIN | 3 MHz | 1550nm Butterfly Laser Diode | 760nm - 3000nm | Wavelength Range |
The standard architectures lasers need two mirrors on both sides of the active zone to form optical cavities. DFB laser has diffraction on the active region serves as a wavelength select component and provides feedback through one mirror.
Because of high output power and stability, DFB laser is primarily utilized for high data rate long-distance transmission and clean single-mode operation.