The simple approach to acquire the fluorescence spectra of vitamin b1,b2 and b6 is proposed by direct illumination on solid powder sample.The experimentally acquired fluorescence spectra are in accordance with the previous measurements on soluble samples.The fluorescence spectra for a mixture of vitamins b1,b2 and b6 with different concentrations have been investigated,and the fluorescence mechanism is explained on the basis of molecular structure.Possible reasons of the blue-shift of the fluorescence peak and enhancement of the peak power are explained as well.The advantages of solid powder method is analyzed and discussed.
A novel all-fiber self-organization coherent Erbium-doped fiber laser is proposed and demonstrated. The laser system is composed of two independent lasers. When each of the two branch lasers operates independently, the output power is 10. 41mW and 8.69 mW respectively. By adjusting a polarization controller (PC), the two lasers achieve coherent coupling, and the output power is 24.4 mW, which is more than two times that the single laser yields. Furthermore, we bring forward and discuss the factor estimating the effect of coherent combination—coherent coupling factor. The value of growth factor to evaluate the effect of coherent combining is 1.27. The coherent fiber laser has the advantages of simple structure, high efficiency and single frequency, which conduce to coherent coupling easily.
JIA Xiu-jie LIU Feng-nian FU Sheng-gui ZHANG Jian LIU Yan-ge GUO Zhan-cheng YUAN Shu- zhong KAI Gui-yun DONG Xiao-yi
An intracavity coherent coupling Michelson erbium-doped fibre （EDF） laser （MCEDFL） is proposed and demonstrated. By using this laser system, we find a means to obtain a maximum power output at the same pumping power level. From the experiment based on fibre Bragg gratings （FBGs） with different refiectivities from 6% to 100%, we find that the reflectivity of the FBG plays a vital role in improving the performance of the MCEDFL. At the same time, the MCEDFL with a polarizer can be coherently combined effectively. This type of system, in principle, is compatible with other more powerful pumping methods, such as cladding pumping, and brings some novel perspectives to the realization of high power lasers.
