fabry perot laser vs distributed feedback laser-difference between fabry perot laser and distributed feedback laser

This page on fabry perot laser vs distributed feedback laser describes basic difference between fabry perot laser and distributed feedback laser types.

As we know in fiber optic chain, laser diode is used as optical source which emits photons. Laser is the short form of "light Amplification by Stimulated Emission of Radiation". Laser light consists of single wavelength emitted in narrow beam.

fabry perot laser

Fabry Perot Laser

The figure-1 depicts spectrum emitted by Fabry Perot Laser as well as schematic diagram of it. Following are the characteristics of this FP laser type.

➨The Fabry Perot laser is the most common type of laser diode.
➨It is used in OTDR design.
➨It is cost effective.
➨It has the ability to deliver high output power level.
➨It is used in singlemode OTDR applications at various wavelengths such as 1310 nm, 1550 nm and 1625 nm.
➨Fabry Perot Laser (i.e. FP laser) emits light at various discrete wavelengths which delivers spectral width between 5 nm to 8 nm.
➨FP laser emits a lot of harmonics over wavelengths in the range from 5 nm to 8 nm.

distributed feedback laser

Distributed Feedback Laser

The figure-2 depicts spectrum emitted by Distributed Feedback Laser as well as schematic diagram of it. Following are the characteristics of this DFB laser type.

➨It is more precise compare to FP laser type.
➨It has output power capability much lower than FP laser type.
➨Distributed feedback laser selects only one principal wavelength in FP laser spectrum. Hence it provides narrow spectral width of less than 0.1 nm.
➨DFB laser functions like FP laser type, except the fact that it contains Bragg grating inside its cavity between two end mirrors.

Laser related links


what is difference between

difference between FDM and OFDM
Difference between SC-FDMA and OFDM
Difference between SISO and MIMO
Difference between TDD and FDD
Difference between 802.11 standards viz.11-a,11-b,11-g and 11-n
OFDM vs OFDMA
CDMA vs GSM
Bluetooth vs zigbee
Fixed wimax vs mobile

RF and Wireless Terminologies