MULTIMODE LIGHT EMITTING MODULE, SEMICONDUCTOR LASER AND OPTICAL FIBER AMPLIFIER

摘要

PROBLEM TO BE SOLVED: To provide a multimode light emitting module in which the variation of a monitor current of a monitor light receiving element can be reduced. SOLUTION: The multimode light emitting module 1 comprises optical resonators 12b and 14c, and a light receiving element 16. The optical resonator comprises a semiconductor optical amplifier 12 and an optical fiber 14 having a grating 14c. Since the grating 14c has an apodized periodic refractive index distribution, a reflection spectrum varies such that the variation of the wavelengthλp imparting maximum reflectivity is slower on a long wavelength side than on a short wavelength side. In the grating 14c, a following relation is satisfied; 0.5 nm>λ0.2 -λp >0.1 nm. Theλ0.2 is given byλ0.2 -λ0.2 , whereλ0.2 represents the larger one of two wavelengths at which relative reflectivity to the maximum reflectivity becomes 0.2 and theλ0.2 represents the smaller one of two wavelengths at which the relative reflectivity to the maximum reflectivity becomes 0.2.