| 摘要 |
<p>The emission linewidth of a semiconductor laser can be reduced by operating it at a wavelength which is less than the wavelength of maximum gain at the threshold current, .lambda. max. An assembly for carrying out such operation comprises a ridge waveguide laser provided with a distributed feedback (DFB) grating. The period of the grating is selected to give a predetermined emission wavelength to the laser which is shorter than .lambda. max. The invention finds application in optical communications, particularly in coherent systems.</p> |
