| 摘要 |
One end of semiconductor laser 1 is coated an antireflection film 1A. And, the external resonator is constructed with a diffraction grating 2 and an external reflective mirror 4. Additionally, a beam splitter 3 is provided between the diffraction grating 2 and the external reflective mirror 4. An output light from antireflection film 1A of semiconductor laser 1 is transformed to a parallel light by the convex lens 5A, and is supplied to the beam splitter 3. The parallel light 13A changes a light path thereof at beam splitter 3, and is then supplied to the external resonator. A wavelength of the parallel light 13A is determined by the diffraction grating 2, so that the light has a selected wavelength, and a phase which is matched with a phase condition of the external resonator. A portion of the resonated light is reflected by the beam splitter 3, and is fed back to the semiconductor laser 1 via convex lens 5A, as a reflected light. When the light is fed back, the semiconductor laser 1 outputs a light of narrow spectral line width. This light is outputted from another end, which is not coated with antireflection film 1A, of semiconductor laser 1, and is transformed to a parallel light by the convex lens 5B. This parallel light 13B forwards to a light isolator 6, is then collected at optical fiber 8 by the convex lens 7. The light which supplied at optical fiber 8 is output to an external apparatus.
|
