• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.12
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• pp.53-62
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• 1999

Center of photon mass(CPM), defined as the center of axial photon distribution, is proposed as a unified design parameter, which contains information about both threshold gain and nonuniformity of axial photon distribution in DFB lasers with low and high-reflection facets. The CPM is inversely proportional to threshold gain and is 0.5 when axial photon distribution is the most uniform. Therefore, a general rule of single-frequency leser design is that main mode CPM should be around 0.5 for-uniform axial photon distribution and side mode CPM should be minimized to maximize the threshold gain difference.