Oki Electric Industry Co., Ltd.

Yoji Hosoi

Takashi Tsubota

Yasumasa Kashima

Masao Kobayashi

A laser diode comprises a substrate, a first blocking layer having a groove, an alternate combination of a lower cladding layer and a second blocking layer, an active layer formed in the groove, and an upper cladding layer. A light-amplifying region and a light-absorbing region are formed alternately in the waveguide. Both regions are disposed periodically at a period corresponding to bragg wavelength.

Laser diode

A superluminescent diode has an active layer confined in a channel cut into current blocking layers on a semiconductor substrate. This structure gives a small output beam diameter and high coupling efficiency, even when coupled into single-mode fiber. At the end of the channel distant from the output facet, the active layer makes slanting contact with a rough diffusing surface formed by the current blocking layers and substrate. This easily-manufactured diffusing surface reduces optical gain within the active layer, thereby preventing lasing without requiring an antireflection coating.

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Tokyo, Japan

Yoji Hosoi