| 摘要 |
<p>A mode-locked laser comprises a two-electrode semiconductor laser (3) including a saturable absorption region (31) and a gain region (32) and an optical waveguide (4) provided outside the gain region (32) of the two-electrode semiconductor laser (3). The optical waveguide (4) comprises a ring resonator (43) having a resonator length equal to an integral fraction of the total resonator length of the mode-locked laser, another ring resonator (44) having passband filter characteristics having a band width narrower than the gain band, and a reflective surface (46) for reflecting laser light, which has reached from the two-electrode semiconductor laser (3) via the first and second ring resonators, toward the two-electrode semiconductor laser (3).</p> |
