| 摘要 |
<p>A tuneable laser having an active section, a phase section and a Bragg reflector comprising a plurality of discrete grating units, at least two of which gratings have a different pitch, wherein current is applicable to at least the grating having a longer pitch, such that the effective wavelength of the grating having a longer pitch can be tuned to the wavelength of the grating having a shorter pitch. A chirp grating can provide the difference in pitch.</p> |
