| 摘要 |
A light emitting module is provided with an optical element having an optical waveguide with a predetermined refractive index, and a semiconductor optical amplifier for generating light in response to an electric current supplied thereto. The semiconductor optical amplifier has an optical emitting facet optically coupled with the optical waveguide, and an optical reflecting facet. The optical element includes the optical waveguide, a diffraction grating optically coupled with the optical waveguide, and electrodes and provided to apply an electric field to the diffraction grating. Light generated from the semiconductor optical amplifier is reflected by the diffraction grating. When an electric field is applied to the diffraction grating by the electrodes, the refractive index of the optical waveguide changes. In accordance with the change of the refractive index, the Bragg wavelength of the diffraction grating changes. As a result, the wavelength of the reflected light can be changed, so that the wavelength of light emitted from the light emitting module can be controlled. <IMAGE> |
