| Stable wavelength locking of a semiconductor laser to a Bragg wavelength of a multimode fiber Bragg grating is demonstrated. Furthermore, it is found that the oscillation wavelength of the semiconductor laser can be selected to the different Bragg wavelengths of a multimode fiber Bragg grating by changing the alignment between the laser diode and the multimode fiber.;Characteristics of the multimode fiber Bragg gratings and multimode fiber Bragg grating-based external-cavity semiconductor lasers are systematically studied. The dependencies of the reflection spectra of multimode fiber Bragg gratings on the excitation conditions, the profile of the refractive index change, the grating length, and the polarization state of the input light are explored. The mechanism of wavelength locking of the multimode fiber Bragg grating-based external-cavity semiconductor lasers is discussed. As well, the effects of the anti-reflection coating of a semiconductor laser on the output spectra of fiber Bragg grating-based external-cavity semiconductor lasers are investigated. |
