抄録
Noise characteristics induced by optical feedback are investigated for two types of single longitudinal mode lasers. One is a conventional VSIS (V-channeled substrate inner stripe) laser and the other is a VSIS laser with a number of grooves on both sides of the V-channel. In this modified VSIS laser, we obtained a thin p-cladding layer and a uniform active layer. In the modified VSIS laser with a uniform active layer, a gain modulation pattern observed in the conventional one is eliminated. In addition, the noise level is found to be smaller than that of the conventional one when optical feedback (F-0.05%) exists, mainly due to the difference in the mode hopping behavior between two types of lasers. These results verify that the uniformity of the active layer is essential for improving the noise characteristics induced by optical feedback.
