Tan Manqing

Theoretical study on erbium ytterbium co-doped super-fluorescent fiber source

Erbium ytterbium co-doped super-fluorescent fiber source (EYD-SFS) has been simulated by a theoretical model based on rate equations and power transfer equations. The output performances of four basic structures of EYD-SFS have been expressed, and it indicated that the DPF structure is a preferable structure. The dependence of output power, mean wavelength and bandwidth stability on the pump fiber length and the concentration of Er3+ and Yb3+ have also been studied. The results indicated with a proper doping concentration of Er3+ and Yb3+ of 6.0 × 1026 ions/m3 and 1.0 × 1027 ions/m3, the optimal gain fiber length is 3.6 cm. In this condition, good performances of DPF structure of EYD-SFS have been achieved.

980 nm fiber grating external cavity semiconductor lasers with high side mode suppression ratio and high stable frequency

The coupling cavity theory is used to analyze the impact of high side mode suppression ratio (SMSR) on fiber grating external cavity semiconductor lasers (FGECSL). The high SMSR and high stable frequency FGECSLs were obtained by experiment. The center wavelength is 974 nm, SMSR is 45 dB, the center wavelength change rate reaches 3.08 ppm/?C in the temperature range of ?20 to 80 ?C.

Long-term storage life of light source modules by temperature cycling accelerated life test

Light source modules are the most crucial and fragile devices that affect the life and reliability of the interferometric fiber optic gyroscope (IFOG). While the light emitting chips were stable in most cases, the module packaging proved to be less satisfactory. In long-term storage or the working environment, the ambient temperature changes constantly and thus the packaging and coupling performance of light source modules are more likely to degrade slowly due to different materials with different coefficients of thermal expansion in the bonding interface. A constant temperature accelerated life test cannot evaluate the impact of temperature variation on the performance of a module package, so the temperature cycling accelerated life test was studied. The main failure mechanism affecting light source modules is package failure due to solder fatigue failure including a fiber coupling shift, loss of cooling efficiency and thermal resistor degradation, so the Norris-Landzberg model was used to model solder fatigue life and determine the activation energy related to solder fatigue failure mechanism. By analyzing the test data, activation energy was determined and then the mean life of light source modules in different storage environments with a continuously changing temperature was simulated, which has provided direct reference data for the storage life prediction of IFOG.

Rapid evaluation method for the normal lifetime of an infrared light-emitting diode

Based on the Arrhenius model, a rapid evaluation method for an infrared diodes normal lifetime is proposed, and the theoretical model is constructed. Accelerated life testing of an infrared light-emitting diode (IRLED), which takes less time than usual, is carried out under temperature and electric current stress. Using this method, the activation energy and the IRLEDs normal lifetime are calculated and analyzed.

Fabrication and characterization of 1 550 nm polarization-insensitive semiconductor optical amplifiers

A 1550 nm polarization-insensitive semiconductor optical amplifier (SOA) was fabricated with InGaAs tensile-strained bulk active region. Beam propagation method and planar wave expansion method are used to calculate the mode field profile and the mode reflectivity. For the SOA with a buried waveguide deviated 70 from the normal direction of cleaved mirrors, the thickness tolerance of the mirror is 3% for keeping the reflectivity of TE mode and TM mode less than 10−4 simultaneously. For a SOA with a cavity length of 800 μm, the polarization sensitivity of amplified spontaneous emission spectra is less than 0.5 dB at an injection current of 250 mA, the corresponding fiber-to-fiber gain is 11.9 dB at 1550 nm with a 3 dB bandwidth of 63 nm, and the saturation output power is 5.6 dBm. The noise figure shows 8.8 and 7.8 dB at 1550 and 1570 nm, respectively. For a packaged SOA with a cavity length of 1000 μm, the fiber-to-fiber gain is 15 dB at an injection current of 190 mA.