Experimental optimization of an erbium-doped super-fluorescent fiber source for fiber optic gyroscopes

Double-pass forward and double-pass backward erbium-doped super-fluorescent fiber sources(ED-SFSs) were combined in one configuration. A980 nm laser diode pumped the same erbium-doped fiber from both directions using a coupler as a power splitter. The double-pass configuration was achieved by coating the fiber end face. Firstly, an optimal fiber length was found to obtain a high stability of output light wavelength with pump power, and then1530/1550 nm wavelength division multiplexing was used for spectrum planarization, which expanded the bandwidth to more than22 nm. The final step was a test of temperature stability. The results show that the rate of the central wavelength change kept to below3.5 ppm/°C in the range of-40 to60°C and1-2 ppm/°C in the range of20-30°C. Considering all the three factors of the fiber optic gyro applications, we selected80 mA as the pump current, in which case the central wavelength temperature instability was calculated as2.70 ppm/°C,3 dB bandwidth22.85 nm, spectral flatness0.2 dB, output power5.17 mW and power efficiency up to9.92%. This experimental result has a significant reference value to the selection of devices and proper design of ED-SFSs for the application of high-precision fiber optic gyroscopes.?2011 Chinese Institute of Electronics

Effect of Mesa Size on Thermal Characteristics of Vertical-cavity Surface-emitting Lasers

The effect of mesa size on the thermal characteristics of etched mesa vertical-cavity surfaceemitting lasers(VCSELs) is studied. The numerical results show that the mesa size of the top mirror strongly influences the temperature distribution inside the etched mesa VCSEL. Under a certain driving voltage, with decreasing mesa size, the location of the maximal temperature moves towards the p-contact metal, the temperature in the core region of the active layer rises greatly, and the thermal characteristics of the etched mesa VCSELs will deteriorate