Development of near-infrared germanium laser operating at room temperature using electron injection into the direct-gap valley.

2015 Fiscal Year Final Research Report

• Project/Area Number: 25246021
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Crystal engineering
• Research Institution: The University of Tokyo
• Principal Investigator: FUKATSU Susumu 東京大学, 総合文化研究科, 教授 (60199164)
• Co-Investigator(Kenkyū-buntansha): YASUTAKE Yuhsuke 東京大学, 総合文化研究科, 助教 (10526726)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ゲルマニウム / レーザー / 直接遷移 / 電子制御バレートロニクス / 量子カスケード類似構造 / 熱い電子 / バレー間ファノン散乱 / 直接バレー電子注入

Outline of Final Research Achievements

Germanium (Ge) is the frontrunner in pursuit of integrating and/or hybridizing the photonic/electronic functionalities on one chip. This is due to the fact that its direct-band-gap emission covers the telecommunication wavelengths besides the compatibility with silicon processing and inherent high carrier mobility. An attempt was made to create a new class of near-infrared interband lasers operating at room temperature using such direct-band-gap emission of Ge. We aimed at defeating the otherwise intractable indirect-gap nature of Ge through the development of a viable valleytronic technique that allows efficient electron injection to the direct conduction-band-valley with an applied field. A deeper physical insight was gained into some of the Ge-specific properties such as hot electrons, intervalley coupling and its impact on the room-temperature Landau splitting, and resonant electronic Raman scattering, which likely make inroads into a new realm leading to novel group-IV lasers.

Free Research Field

応用物理学