High power, broadband light source by tandem combination of a superluminescent diode and an er doped fiber amplifier

Abstract

Broadband light sources have been proven to be very useful in fiber gyro applications. In the past, the broad band light sources which have been used for fiber gyro applications are light emitting diodes (LED), superiuminescent diodes (SLD), and superfluorescent fiber light sources (SFF). Let us compare these light sources performances at the 1550 nm wavelength. LEDs have a very wide spectrum (~100 nm FWHM), but very low fiber coupled power (~10 μW.). SLDs have about 50 nm spectral width and about 1 mW fiber coupled power [1]. SFFs have high output power (typically a few mW depending on pump power) and very stable optical spectrum with respect to temperature variation. However, SFFs have undesirable twin peak characteristic (at 1532 and 1558 nm) in the fluorescence spectrum. At high output power, the peak at 1532 nm dominates and the resulting spectral width is very narrow (~2 nm) [2].