Distributed feedback type semiconductor device

Abstract

Abstract PURPOSE:To enable excellent oscillation of single axial mode by giving the periodical distribution of refractive index to a section of the strongest photo field by a method wherein the neighborhood betweeen an active layer and an optical guide layer is provided with a grating layer made of a semicondoctor material having refractive index lower than both have, and the layer thickness thereof is varied periodically. CONSTITUTION:A non-doped InGaAsP active layer 12 and a P type InP grating layer 13 are epitaxially grown on an N type InP substrate 11, and a grating is formed to the layer 13. Next, a P type InGaAsP optical guide layer 14, a P type InP clad layer 15, and a P<+> type InGaAsP contact layer 16 are epitaxially grown so as to fill the grating layer 13. Since the DFB laser thus manufactured is given a large periodical distribution of refractive index by the P type InP grating layer 13 buried between the active layer 12 with the strongest photo field and the optical guide layer 14 in periodical form, the excellent coupling of the photo field with the grating can be obtained, thus showing excellent oscillation of single axial mode.

Inventors

• 👤 Masayuki Yamaguchi
• 👤 山口　昌幸

Bibliographic Details