Semiconductor laser device

Abstract

Abstract PURPOSE:To facilitate the formation of a diffraction grating and to improve the coupling efficiency of the grating by forming the grating as a tertiary diffraction grating, and forming the sectional shape of periodic uneven state substantially in a rectangular shape. CONSTITUTION:An n-type current blocking layer 2, a p-type clad layer 3, a p-type active layer 4, an n-type InGaPAs guide layer 5, an n-type clad layer 6, a cap layer 7 are laminated on a p-type GaAs substrate 1, and electrodes 8, 9 are respectively formed on the lower surface of the substrate 1 and the upper surface of the layer 7. Periodic uneven state is formed on a boundary between the layers 5 and 6 as a diffraction grating. The groove of the grating is directed in a direction (0-1-1), and uneven state is periodically continued in a direction (0-1 1). The period of the uneven state is so set that the grating becomes tertiary. The shape of the grating is rectangular wave shape. Thus, the grating is formed in the tertiary rectangular wave shape to increase the pitch of the grating. Accordingly, the control of marking and shape is facilitated, and the coupling efficiency is improved to reduce a threshold current.

Inventors

• 👤 Hiroaki Kudo
• 👤 裕章 工藤
• 👤 Haruhisa Takiguchi
• 👤 滝口　治久
• 👤 Shinji Kaneiwa
• 👤 進治 兼岩
• 👤 Chitose Sakane
• 👤 坂根　千登勢

Bibliographic Details